Safety Document Group 3

Occupational Safety Training Materials in the Construction Sector

Posted on by LÊ THẾ QUÝ
Occupational Safety Training Materials in the Construction Sector
03
Apr
Home > Occupational safety training > Study and get certified > Occupational safety knowledge > Occupational safety documents > Safety Document Group 3 > Occupational Safety Training Materials in the Construction Sector

DOWNLOAD THE OCCUPATIONAL SAFETY DOCUMENT SUITE (6 GROUPS, OVER 300 PROFESSIONS)

In recent years, Occupational Safety and Health has always been a concern for businesses and has achieved positive results. However, there are still limitations and weaknesses that need to be addressed. Many organizations and individuals who employ labor have not demonstrated a high sense of responsibility and have violated legal regulations on Occupational Safety and Health. The majority of workers still lack the knowledge, skills, and proactiveness in preventing occupational accidents and diseases.

The materials for the occupational safety training course in construction will help workers equip themselves with safety knowledge and prevent hazards on the construction site.

Table of Contents

CHAPTER 1: SAFETY TECHNIQUES IN CONSTRUCTION WORK

1. Occupational safety during demolition of structures in the construction safety document

a. Risks of occupational accidents during demolition of structures in the construction safety document

When demolishing structures, the risks affecting workers’ health and causing occupational accidents are very high, including: dust, noise, dirty water, foul odors; or falls, being hit by falling or flying concrete, bricks, steel, or wood; or the sudden collapse of loads on structural columns, beams, and floors; or damage to surrounding structures and people…

b. Preventive measures for occupational accidents during demolition of structures in the construction safety document

The demolition method must be established and checked by a qualified person, paying attention to the site layout, demolition method with detailed drawings… including:

  • Before demolition: Survey and assess the condition of the foundation, footings, and other structures…; The entire electrical system, water system, and other technical systems of the structure must be disconnected;
  • During demolition: Ensure safety for people and the surrounding environment, such as noise from machinery, air pollution from dust; pay attention to the structure, construction materials…;
  • A closed fence system with a height of at least 2m must be used to avoid attracting the attention of people outside the structure and to prevent workers inside from looking out;
  • There must be posters and notices placed at workstations, rest rooms, and restrooms reminding workers to practice good hygiene;
  • There must be solutions to prevent dust, and waste must not be burned on the construction site;
  • The demolition plan must clearly state:
    • Measures for managing site entry and exit; working and non-working hours; + Checking the continuity of the structure;
    • Adequate placement of warning signs, barriers, and fire and explosion prevention systems;
    • Collecting and transporting waste and keeping the construction site always neat and clean;
    • Providing full personal protective equipment for workers;
    • There must be continuous supervision throughout the demolition process;
    • Emergency plans and first aid measures in case of an accident.

2. Occupational safety in loading, unloading, and transporting materials

a. Risks of occupational accidents when loading, unloading, and transporting materials in the construction safety document

  • When handling materials with incorrect methods, it can cause injury to the spine, or workers may not be provided with personal protective equipment, or they may not comply with technical procedures, leading to accidents at work…

b. Safety measures when loading, unloading, and transporting materials in the construction safety document

  • Workers must be in good health and fully equipped with personal protective equipment as required for each type of work and must be instructed on the working methods;
  • There must be specific plans and measures to ensure safety for each job;
  • When a vehicle is carrying loose materials, the materials must be at least 10cm below the truck bed. Do not exceed the vehicle’s specified load capacity;
  • When transporting long and bulky materials, they must be securely tied down. If the cargo is 1.5 times longer than the truck bed, a trailer with a floor height equal to the truck bed’s floor must be used;
  • Box-shaped materials or bags (cement) should be stacked neatly and close together. Pipe or bar-shaped materials should be placed on sturdy racks. Cylindrical materials like drums should be placed in a single layer on the ground and chocked with wedges;
  • The best place to store materials is in a warehouse; otherwise, there must be a roof or tarpaulin to protect them from rain and sun; For stacks of bricks, they should not be stacked more than 25 rows high;
  • Comply with measures to ensure occupational safety when using machinery to transport materials and equipment on a construction site.

c. Hygiene on the construction site in the construction safety document

  • Clean up the site neatly after each work shift; dirt should be transported away immediately after being excavated.
  • Scrap wood, waste paper, or dry mortar debris… on the floors must be brought down and gathered in one location and must be transported off the site.
  • Oil and grease from construction machinery must not be allowed to flow into the natural environment. Measures such as tightly closing cans and drums must be taken to prevent them from spilling. Regularly check the condition of containers for holes or rust to plan for transferring the oil or grease to another container.
  • At the site office: It should be cleaned regularly to create a good working space for staff.
  • On the construction site, there must be separate sanitation areas for men and women, located downwind. In addition, there must be bathing areas for workers and staff after each work shift.

3. Occupational safety during the construction of the substructure in the construction safety document

a. Excavation with sloped sides (excerpt from QCVN 18: 2014/BXD) in the construction safety document

  • When excavating foundation pits and trenches, to prevent landslides, slopes must be created with angles of inclination not greater than the values in the following table:
SOIL TYPE SOIL CONDITION
DRY MOIST WET
Angle of slope to horizontal Ratio of slope height to horizontal projection Angle of slope to horizontal Ratio of slope height to horizontal projection Angle of slope to horizontal Ratio of slope height to horizontal projection
Gravel, pebbles 40 1: 1.20 40 1: 1.20 35 1: 1.45
Coarse sand 30 1: 1.75 32 1: 1.60 25 1: 2.15
Medium sand 28 1: 1.90 35 1: 1.45 25 1: 2.15
Fine sand 25 1: 2.15 30 1: 1.75 20 1: 2.77
Sandy clay 50 1: 0.84 40 1: 1.20 30 1: 1.75
Organic soil 40 1: 1.20 35 1: 1.45 25 1: 2.15
Peat soil without roots 40 1: 1.20 25 1: 2.15 15 1: 3.75

 

  • Do not excavate water-saturated sand or sandy soil without a shoring system.
  • For slopes longer than 3m and with a slope greater than 1:1, or slopes with a slope greater than 1:2 but are wet, workers on them must wear safety harnesses tied to a securely anchored stake;
  • Machinery working near trenches and pits must ensure that the distance from the nearest support point of the machine to the trench or pit is not less than the value in the following table:
DEPTH OF PIT (m) SAND SANDY SOIL CLAYEY SOIL CLAY
Horizontal distance from the nearest support point of the machine to the toe of the slope of the trench or pit (m)
1 1.5 1.25 1 1
2 3 2.4 2 1.5
3 4 3.6 3.25 1.75
4 5 4.4 4 3.0
5 6 5.3 4.75 3.5

 

b. Foundation reinforcement in the construction safety document

When a structure is built on a foundation that is not too weak, a foundation reinforcement solution is often chosen to bear the building’s load. There are many different ground improvement technologies, but the most common are sand piles, cement piles, lime-soil-cement piles, and bamboo piles. People use machines or mechanical hammers, hand hammers to drive these piles into the ground, so there are risks of occupational accidents when reinforcing the foundation, such as:

  • Construction machinery causing accidents for workers; + Objects falling or toppling from above;
  • Incorrect operation of technical procedures;
  • Equipment, materials, and supplies not meeting quality specifications…

Preventive measures for occupational accidents when reinforcing the foundation:

  • Preparing the construction site and correct technical plans;
  • Checking the safety condition of machinery, equipment, materials, and supplies before construction;
  • Workers must be in good health and have received occupational safety training;
  • Supervising and inspecting the construction process and having a plan to handle any incidents that occur…

c. Construction of driven piles, pressed piles, and bored piles in the construction safety document

  • Risks of occupational accidents during pile construction
    • This involves using various types of supporting machinery to drive, press, or bore piles into the ground to create a solid foundation base. Therefore, there are risks of occupational accidents, such as:
      • Lack of records, history, and instruction manuals for machine installation, use, and maintenance.
      • Failure to register, inspect, or perform maintenance and repair of machinery and equipment as required, or lack of hazard warning devices…
      • Lack of lighting or protective guards, warning signs, and barriers in hazardous areas.
      • Unclear assignment of responsibility for managing and using machinery; machine operators lacking the professional qualifications, skills, and experience to handle incidents… such as: violating internal rules; using machinery not for its intended purpose or technical capabilities; lack of awareness while working…
  • Preventive measures for occupational accidents during pile construction
    • Measures for organizing machine management:
      • The head of the unit must assign responsibility in writing to the unit and individuals for managing and using the machinery, including: Managing records, history, descriptions, and technical instructions for safe installation, maintenance, and use; performing registration and inspection as required by the State;
      • Performing periodic maintenance and repair of machinery. In case of an incident or damage to the machine, it must be repaired, tested, and inspected according to the manufacturer’s regulations.
    • Machine operators must meet all the following standards:
      • Have a health certificate issued by a competent medical authority;
      • Have a diploma or certificate of professional training as required;
      • Have a card or certificate of occupational safety training;
      • Workers must be fully equipped with appropriate personal protective equipment.
    • Ensuring good machine quality and safe operation, such as:
      • Having full and appropriate safety devices that operate accurately and reliably (automatic safety devices, preventive devices, and devices that signal danger);
      • Inspecting and testing the durability and reliability of moving parts, mechanisms, and machine components such as cables or chains… (according to TCVN 244:2005).

Construction safety document

      • Testing structural components, brakes… of the equipment.

Construction safety document
Construction safety document
Construction safety document

    • Ensuring the stability of construction machinery: this is a necessary condition for the safe use of machinery. Stability must be ensured for stationary machines, when moving, during operation, or when not in operation, paying attention to:
      • Do not overload the crane, lift or lower the boom quickly, or brake suddenly when lifting a load. + Do not place the crane on a foundation or track with a steep slope.
      • Do not swing the crane or boom quickly; do not work in winds of level 5 or higher.
    • Installing protective guards and barriers in hazardous areas of the machine:
      • Protective guards and barriers serve to prevent parts of the worker’s body from entering the machine’s hazardous area to avoid occupational accidents.
      • Both protective guards and barriers must meet the requirements of preventing hazardous factors from affecting people and being durable under mechanical, thermal, or chemical impacts.

d. Excavating foundation pits in the construction safety document

  • Risks of occupational accidents when excavating foundation pits
    • The soil wall collapses and buries the worker below, such as:
      • The pit has vertical walls that exceed the height and slope limits for each type of soil; + The pit wall collapses due to moisture, rain, or groundwater causing the soil wall to fail; + Due to materials or excavated soil being piled near the edge of the pit, affected by vibrations…;
      • When installing or dismantling the wall shoring structure incorrectly, it can render the shoring system ineffective or cause strong vibrations that lead to soil collapse…
    • A person falls into the pit:
      • Ascending or descending a deep pit without a ladder or without creating steps on the pit wall; climbing on the soil wall shoring structures; working on a steep slope without wearing a safety harness;
      • No barriers, no warning lights at night…
    • A worker is asphyxiated by toxic fumes or gases: Toxic fumes and gases are often encountered when excavating pits near old landfills, near sewage lines, etc., such as CO₂, CH₄…
    • Occupational accidents due to underground power cables, underground pipelines, bombs, mines…
  • Preventive measures for occupational accidents when excavating foundation pits
    • Preventing soil wall collapse: According to TCVN 5308-1991, the critical depth of a pit with vertical walls is specified as follows:
      • Not more than 1m for sand and loose soil or newly filled soil; + Not more than 1.25m for sandy soil;
      • Not more than 1.5m for clayey soil and clay;
      • Not more than 2m for very hard soil that requires a crowbar or pickaxe to excavate;
      • When excavating a deep pit or trench by machine in cohesive, high-density soil, vertical soil walls up to 3m deep are permitted, but no one is allowed below. If workers are needed below, the area must be shored or excavated with sloped sides;
      • Regularly check the stability of the pit walls; do not undercut.
    • Excavating a pit with vertical walls and shoring:
      • Use planks 4-5 cm thick, place them horizontally against the soil wall as excavation progresses, with vertical posts on the outside and horizontal braces;
      • For deep pits, the shoring must be done in several stages from top to bottom, each stage being 1-1.2m high (suitable for the working height of a worker);
      • Do not cause strong impacts to the bracing system during manual or machine excavation or when performing other tasks inside the foundation pit;
      • Always monitor the shoring structure of the excavated pit and promptly handle any issues that arise.
    • Preventing people from falling into the excavated pit
      • A ladder or soil steps must be used for workers to ascend and descend;
      • Do not jump over or climb on the soil wall shoring structure;
      • A safety harness must be worn when working on a slope greater than 45° and the pit depth (slope height) is greater than 3m, or on a soil slope less than 45° that is wet and slippery;
      • There must be sturdy barriers at least 1m high and warning signs 1m from the edge of the pit (trench); at night, there must be warning lights if the pit is excavated near a high-traffic area;
      • If work is temporarily suspended, the foundation pit must be covered with a net;
      • To cross the pit: a bridge at least 0.8m wide (for one-way traffic) and 1.5m wide (for two-way traffic) must be built. The bridge must have a railing at least 1m high and be illuminated at night.
    • Preventing soil (rock) from rolling or falling from above
      • When dumping excavated soil (rock) from below, it must be at least 0.5m away from the edge of the pit and have a slope of no more than 45° to the horizontal;
      • Install a retaining board about 15cm high to prevent soil or objects from falling into the pit;
      • During breaks, no one is allowed to sit at the bottom of the pit;
      • When excavating with a machine, workers are prohibited from standing within the swing radius of the excavator’s boom while the machine is operating;
      • Do not work at the edge of the pit while there are people working below;

Construction safety document

Construction safety document

    • Preventing asphyxiation from toxic gases in the construction safety document
      • When excavating a pit, if unpleasant fumes or gases are detected, or if a person experiences dizziness, difficulty breathing, headache, etc., stop immediately and move away from the construction area. When the issue has been resolved and it is ensured that there are no longer dangerous fumes or gases to health, work can resume. If work must continue in an area with toxic fumes or gases, a gas mask, oxygen tank, etc., must be used;
      • Before descending into a deep pit, test for toxic fumes and gases with specialized equipment;
      • If toxic fumes or gases are detected, a fan or exhaust fan must be used to clear them.

Construction safety document

  • Preventive measures for occupational accidents when constructing basement retaining walls
    • Have a safety solution for the retaining wall;
    • The temporary bracing system must be strong enough to bear the load and not deform or become unstable;
    • Workers are strictly prohibited from working or climbing on the horizontal braces of the basement retaining wall without wearing a safety harness or without scaffolding;
    • Prevent groundwater from bursting through the bottom or sides of the basement or adjacent areas;
    • Strengthen inspection, supervision, and safety training for workers.
    • Have measures to prevent, handle incidents, and respond to emergencies in case of an unsafe event.

Construction safety document
Construction safety document

4. Occupational safety during the construction of the superstructure in the construction safety document

a. Occupational safety in the fabrication, erection, and dismantling of formwork in the construction safety document

Formwork in construction is mainly for components such as foundations, walls, columns, beams, floors, and stairs, etc., and is constructed from panels connected together and held securely in place by a system of yokes, walers, vertical or inclined props… Workers erecting and dismantling formwork almost always have to work at height above the ground. When dismantling formwork, there are many nails or sharp wood scraps… that can cause occupational accidents:

  • Risks of accidents in the fabrication, erection, and dismantling of formwork
    • During the process of fabricating, erecting, and dismantling formwork, workers are at risk of occupational accidents such as:
      • Accidents caused by the use of fabrication machinery and tools (circular saw, planer, handsaw, chisel…);
      • Workers falling during the installation and dismantling of formwork;
      • Using low-quality scaffolding, frames, or supports, or those that do not meet the safety requirements for load-bearing capacity and stability, resulting in collapse;
      • Work platforms without guardrails, working in precarious and dangerous places without wearing a safety harness;
      • Formwork, tools, or materials collapsing, falling, or being thrown from a height;
      • Stepping on nails or getting scraped by the sharp edges of formwork, components…
  • Preventive measures for occupational accidents in formwork construction
    • Comply with safe working procedures for machinery, tools, and supporting equipment;
    • All types of machinery, hand tools… must be sturdy, safe, and convenient, and must be regularly inspected and maintained;
    • To prevent formwork collapse, it must be constructed according to the technical design;
    • A safety harness must be worn, and the safety harness must be secured to sturdy structures;
    • When installing or dismantling formwork at a height of 1.5m or more above the ground or floor, workers must stand on a sturdy work platform, which is placed on a support frame, trestle scaffold, or high scaffold, with a guardrail at least 1m high and two horizontal bars spaced 30cm apart;
    • When installing formwork for columns or beams up to a height of 5.5m, mobile trestle scaffolds can be used; if higher than 5.5m, a high scaffold must be used;
    • Do not gather a large number of people on slip formwork platforms and hanging scaffolds;
    • When installing large panel formwork in several lifts, the upper lift can only be installed after the lower lift formwork has been securely fixed. Pre-assembled formwork in blocks or large panels must be sturdy and avoid impact with previously installed structural parts when lifted by machine;
    • The support system must be placed on a solid foundation to avoid settlement during construction;
    • When dismantling formwork, props… they must be immediately brought down to the floor. Heavy, bulky formwork parts must be supported by winches, pulleys, cranes…; do not throw them from a height;
    • There must be signs and warnings for the work area and hazardous areas, restricting or prohibiting people from passing underneath the construction site;
    • Formwork can only be dismantled after the concrete of the structure has reached the allowable strength and with the permission of the responsible technical officer; dismantling is carried out from top to bottom, dismantling one part at a time, do not pull down large sections at once;
    • While dismantling formwork, constantly observe the condition of the structural parts; if there are signs of deformation such as sagging or cracking, stop dismantling and immediately report to the construction technical officer;
    • Workers must be trained in safety and be continuously supervised during construction.

Construction safety document

Construction safety document

b. Occupational safety in rebar fabrication and installation in the construction safety document

When fabricating and installing rebar, machines such as rust removers, cutters, and benders, or hand tools like clamps, hammers, or anvils are used, so the following accident risks exist:

  • Risks of occupational accidents in rebar fabrication and installation
    • Accidents caused by supporting machinery and tools, such as clamping, rolling, or hitting workers’ hands and feet, or electric shock, or possibly being electrocuted or touching bare electrical wires…;
    • Tripping or stepping on sharp iron bars, or pieces of iron flying into people;
    • Slipping and falling on the floor surface, or a concentration of many people causing the floor to collapse;
    • Steel frame cages, iron bars can fall, topple, and crush people.

Construction safety document
Construction safety document

  • Preventive measures for accidents in rebar fabrication and installation
    • Workers must strictly adhere to the safety rules when using machinery and equipment during rebar fabrication and installation;
    • Before starting work, run the machine without a load to check it;
    • When working, workers must wear safety glasses and gloves;
    • Clean dust and metal shavings from the workbench or fabrication machine with a vacuum pump or brush. It is forbidden to use hands to brush away dust and iron shavings (even with gloves);
    • For mechanical drive cutting machines, it is forbidden to cut rebar pieces shorter than 30cm without a protective guard;
    • For bending machines, the position of the rebar can only be adjusted, and the rebar can only be chocked, and the locking pin and jig on the machine can only be reset when the machine’s disk is not rotating;
    • All types of rebar fabrication machines must be grounded or have a neutral connection to ensure electrical safety;
    • After fabrication, the rebar should be neatly stacked in the designated area, not left on or next to the machine or in walkways;
    • There must be measures to prevent rebar from breaking due to excessive tension during stretching;
    • To prevent the rebar from slipping, the end of the rebar must be secured to the end of the pulling cable with a clamping device, not by tying;
    • Workers must not stand near the rebar while it is being tensioned. The rebar tensioning area must be fenced off to prevent unauthorized entry. When the rebar has been straightened, the winch must be slowly braked to reduce the tension until the winch stops completely, at which point workers can approach to remove the end of the rebar from the clamp and take out the straightened rebar;
    • When cutting steel manually, very good tools must be used: hammers must have sturdy handles, the hammer head must not have burrs or frays, and must be tightly wedged into the handle. Chisels must be sharp, and the cutting edge must fit snugly with the diameter of the rebar being cut. The person swinging the sledgehammer must not wear gloves. The person swinging the hammer and the person holding the chisel must coordinate very smoothly. While working, they must concentrate on the job;
    • Rebar can be bent manually if the amount of rebar is small and the diameter is not more than 20mm. Pay attention to securing the bending table firmly to the floor and securely driving the steel pins on the bending table (used as a fulcrum for bending the rebar);
    • Reinforced concrete components such as foundations, columns, beams, or floors, after the formwork has been erected, the rebar must be installed, and the steel bars must be linked together to form a steel frame or steel mesh by welding or tying;
    • When connecting rebar by tying, a tying hook must be used; workers must wear gloves during the work process;
    • When installing rebar for structures such as columns, beams, or walls at height (over 1.5m above the ground or floor level), workers must stand on a sturdy work platform with a safety rail. Do not stand or cling to the steel frames or mesh of columns, beams, or walls;
    • A fixed ladder must be used for ascending and descending; do not climb on the steel frames or mesh;
    • Do not stack rebar on the work platform or on the formwork system during construction;
    • Before moving rebar cages to the installation position, check the welds, ties, and lifting points when using cables for lifting and transport;
    • There must be measures to prevent rebar from touching electrical wires if the rebar is erected and installed near power lines…

c. Occupational safety in concrete mixing and pouring in the construction safety document

Currently, construction sites often use forced concrete mixers to supply concrete during construction. There are many different types of forced concrete mixers, such as mini and regular types…

  • Risks of occupational accidents when mixing and pouring concrete
    • A worker standing under the material loading bucket while it is being raised without being securely fixed may have the bucket suddenly drop if the brake fails or the holding cable breaks;
    • A worker accidentally or intentionally puts a shovel into the mixing drum while the machine is rotating;
    • Repairing the machine while it is in operation;
    • The formwork and propping system are not strong enough and partially or completely collapse during concrete pouring;
    • The walkway or planks are not sturdy or are too weak, causing a worker to fall while transporting concrete;
    • The buckets (baskets) for transporting concrete are not of a suitable size (too large), exceeding the worker’s endurance after a period of work, or they break…;
    • The posture for lifting the bucket (basket) onto the worker’s shoulder or head is incorrect, causing them back pain, headaches, or body aches;
    • The concrete pouring bucket is too weak and may break or leak during lifting and transport;
    • The discharge gate of the pouring bucket opens unexpectedly because the bucket’s locking pin slips or is damaged, causing concrete to spill out of the bucket while being lifted;
    • The cable for lifting the pouring bucket may slip or break while transporting concrete;
    • A worker may be electrocuted while vibrating concrete with a vibrator due to an exposed electrical wire (when moving the vibrator from one position to another, the wire rubs against the rebar and becomes exposed) or the vibrator’s casing being live;
    • The concrete pump boom touches a power line near the construction site;
    • High risk of falling when pouring concrete on floors, beams, etc…
  • Preventive measures for occupational accidents when mixing and pouring concrete
    • Only workers who have been trained in their specialty and in occupational safety are allowed to operate and service concrete mixers and vibrators;
    • The pit and loading bucket of the mixer can only be cleaned after the bucket has been securely fixed in the raised position;
    • Workers must not stand under the bucket until it is securely fixed;
    • The mixer must be grounded or have a protective neutral connection to prevent electric shock from a live casing;
    • Do not repair malfunctions of the concrete mixer while it is in operation;
    • Do not put shovels, hoes… into the mixing drum while it is rotating;
    • After a mixing cycle, the mixing drum must be washed clean; do not let concrete harden in the drum. When scraping and cleaning the mixing drum, the circuit breaker must be switched off, and one must wait until the machine has completely stopped. The circuit breaker must be placed in a locked, enclosed box. When repairing or cleaning the machine… a warning sign must be hung there, such as: “Do not switch on power, people are working”…;
    • Before pouring concrete, the technical officer must inspect the condition of the formwork, rebar, props, and work platform to prevent the formwork system from breaking or collapsing;
    • The walkway below the area where concrete is being poured must have a barrier and a prohibition sign.
    • If people must pass through, protective covers must be installed above the walkway;
    • The floor planks for workers to transport concrete must be sturdy and stable;
    • Before transporting and pouring concrete with a crane, the safety of the crane must be checked; the concrete bucket must be sealed and sturdy, and the bucket gate must have a locking pin…;
    • Pour concrete when the components, rebar… have been fully installed;
    • When pouring concrete from a height of over 1.5m, to avoid segregation, an elephant trunk hose or an inclined chute can be used. In that case, the concrete hopper, elephant trunk hose, and inclined chute must be securely fixed to the formwork or work platform;
    • When pouring concrete at a height of 1.5m or more above the ground or floor, workers must stand on a sturdy work platform with a safety rail;
    • When working with concrete on structural parts with an incline of 30° or more, workers must wear a safety harness;
    • When working with concrete outdoors, there must be a shelter from rain and sun; at night, there must be lighting, with a general illumination level of 40-80 lux (maximum 150 lux);
    • When compacting concrete with a vibrator, measures must be taken to prevent electric shock (grounding, neutral connection, power supply cable must have a rubber sheath…) and to reduce the harmful effects of the machine’s vibration on the body. The operator of the vibrator must be in good health when starting the job and must undergo periodic health checks;
    • While working with a surface vibrator, do not press on the vibrator with your hands; use a soft pulling rope to move the vibrator, do not pull on the power cord or cable to move the vibrator;
    • To prevent the vibrator from overheating, turn off the machine and rest for about 5-7 minutes for every 30 minutes of work to let the machine cool down, and do not cool it down instantly with water;
    • When taking a break or leaving the work area, turn off the vibrator;
    • After finishing work, the vibrator and power cord should be cleaned of concrete and dirt, wiped dry, the cord coiled, and stored in a warehouse;
    • The operator of the vibrator should use gloves with a thick padded palm;
    • When curing concrete, scaffolding or supports must be used. Do not stand on props or the edges of formwork. Do not lean a ladder against concrete structural parts that are being cured; if curing concrete at night or on structural parts that are obscured, there must be lighting…

Construction safety document
Construction safety document

d. Occupational safety in assembly work in the construction safety document

In civil construction, structures are not always built using cast-in-place reinforced concrete. Many structures are built by assembling pre-manufactured components in a factory to become a complete structure. The pre-manufactured components can be wood, structural steel, or reinforced concrete, including foundations, columns, beams, panels, or prestressed floors, etc.

The method of assembling components is to use a crane to lift them into their designed position. Then, the joints of these components are fixed using bolts, welding, or by pouring concrete… Usually, the assembly of components is mainly carried out at height above the ground or the floor levels, which poses a risk of accidents.

  • Risks of occupational accidents in assembly work
    • Using a crane for assembly that does not meet the technical specifications such as weight, distance, and installation height of the components… can lead to the crane being overloaded, the boom overreaching, the component being dragged or colliding with previously installed structures, causing the structure to collapse or the crane to break and fall;
    • The lifted component falls due to the use of improper slinging tools and methods, such as insecure knots, lifting slings or hooks not being strong enough… Incorrect determination of the component’s lifting points causes the component to lose balance, swing, tilt, or change the load-bearing capacity of the structural parts, leading to breakage, fracture, or deformation, or the lifting lugs or hooks breaking off the component…;
    • The component falls or topples when being adjusted and fixed into its designed position (when the component has been detached from the crane’s hook). Insecure temporary fixing also causes the component to topple;
    • Falling due to working on a work platform without wearing a safety harness;
    • Assembling not according to the designed sequence, not ensuring the stability of each component or of the structural part;
    • Welded, riveted, bolted connections, or poured concrete joints between components not meeting quality standards;
    • Workers serving the assembly work (crane operator, rigger, assembler, or welder,…) violating labor discipline and occupational safety rules, such as: walking, going up and down without using a ladder but climbing on top of the components being assembled, clinging to or sitting on the component, throwing or catching materials and tools at height…
  • Preventive measures for occupational accidents in assembly work
    • General preventive measures
      • To prevent occupational accidents in assembly work, basic technical safety measures must be studied and proposed in the design, and members of the assembly team must be trained to understand and correctly implement them during construction.
      • The description and drawings of the assembly construction design must specify: + The type of crane used for assembly;
        • The position and method of arranging the components on the lifting and assembly site; + The layout and operating area of the assembly crane;
        • The tools, accessories, and methods for slinging the components; the method for reinforcing and strengthening the components before lifting, if necessary;
        • The sequence of assembling the components of the structure;
        • The method of assembling each type of component into its designed position: lifting, installing, adjusting the component into position according to the design, temporary or permanent fixing;
        • Arrangement of means for working at height (scaffolding, trestle scaffold, hanging scaffold, ladder, or work platform,…).
      • Arrangement and placement of components on the lifting and assembly site
      • The components must be arranged within the operating range of the crane and be stacked according to the correct height and distance between the stacks of components.
      • The height of the stacks of concrete and steel components is specified as follows: + Floor panels stacked in 10 to 12 layers with a height not exceeding 2.5m; + Foundation and wall blocks stacked in four layers, not exceeding 2.25m;
        • Beams and columns not higher than 2m;
        • There must be wooden dunnage with a cross-section of 60 x 60mm or 100 x 100mm between the layers; + Wall panels must be stacked in A-frame racks;
        • A minimum distance of 1m must be left between the stacks of components.
      • Preventing incidents or occupational accidents when using an assembly crane
        • Have measures to prevent accidents when working with construction machinery and equipment;
        • The cranes for lifting must meet the required parameters for assembling components in terms of weight, size… and their installation position on the construction site;
        • In all cases, do not lift a component whose weight is greater than the crane’s lifting capacity at the corresponding reach;
        • Do not lift a component that is buried in the ground or is under another heavy object;
        • Do not lift a component beyond the maximum reach, do not drag a component, and workers must not pull or push a component while it is suspended in the air.
      • Preventing a component from falling when slung
      • Slinging components for lifting is a very important operation to prevent them from slipping, breaking, or falling, causing occupational accidents, such as:
        • The lifting slings are usually steel cables with a diameter and load-bearing capacity calculated to be suitable for the weight of the lifted object;
        • The knots must be tight, the lifting points must be secure, to prevent the component from slipping and falling during lifting;
        • The lifting slings must be inspected regularly. If the number of broken steel wires in the cable or the diameter of the cable is worn beyond the specified limit, it must be discarded.
        • The lifting points of the component must be chosen so that when lifted, it is in a balanced state, without tilting or flipping. If the component has sharp edges, the sling points must be padded with wood or rubber to prevent the sling from being abraded or cut… The padding must be securely attached to the component or the sling, so it does not fall when the sling is slack or when the component has been placed in position.
        • The crane hook as well as the hooks at the ends of the slings must have a safety latch to prevent the cable from slipping off the hook, causing the component to fall.
      • Preventing occupational accidents when lifting and moving components
        • When moving a component horizontally, it must be lifted at least 0.5m higher than other objects;
        • For components longer than 6m, tag lines with a diameter of not less than 25mm or small steel cables can be used to steady and control the component from rotating;
        • If the weight of the component is close to the crane’s capacity at the corresponding reach, check the stability of the crane and the safety of the brake by test-lifting the component to a height of 10-20 cm. If the load or the crane is not balanced, the load must be lowered to the ground for readjustment. It is forbidden to adjust the load while it is suspended;
        • During lifting and moving, it is strictly forbidden for people to cling to, sit on, or stand on the component, and it is forbidden to place any object on it unless it is securely tied down;
        • During the assembly of components, the hazardous area must be fenced off and have signals and warning signs. It is forbidden for people to stand underneath while assembly is in progress, as well as in the area where components are being moved by the crane;
        • It is forbidden to leave an assembled component suspended in the air during work breaks.
      • Preventing a component from falling or toppling during lowering, placing, and adjusting
        • Component installation: when the component has been lowered to within 30cm of its set point, workers can approach to guide, place, and adjust it into its designed position;
        • The crane hook can only be detached from the component after it has been installed and securely fixed;
        • After the component has been detached from the hook, it is forbidden to make any other movements. If the position of an installed component needs to be adjusted, it must be re-slung to the crane’s hook, lifted, and adjusted while suspended from the hook;
        • To temporarily fix the components that have been placed in their designed position, appropriate temporary fixing devices must be used for each type.
      • Preventing assembly workers from falling from a height
        • To prevent falls from height during assembly, the construction design must specify the location for installing means for working at height (high scaffold, trestle scaffold, hanging ladder, hanging cradle,…);
        • When ascending (descending), a hanging ladder attached to a sturdy structure must be used; do not climb on the parts of the structure, walk on top of walls, beams, purlins, or roof trusses…;
        • When assembling in positions where there is no protective equipment for working at height, a safety harness must be worn, and this harness must be tied to sturdy locations;
        • Assembly workers must be experienced and knowledgeable about assembly safety measures, and must be equipped with personal protective equipment when working;
        • There must be a construction technical officer or team leader to guide and supervise construction throughout the assembly process;
        • Lifting must be stopped when there is a wind of level 5 or higher, or when it is dark.
      • Preventing occupational accidents when assembling steel components
      • In addition to the preventive measures for occupational accidents mentioned above, when assembling steel components, the following measures should also be noted:
        • For large steel components, before lifting, they must be reinforced with temporary bracing devices to ensure stability and prevent deformation, warping, or even local deformation or breakage;
        • Install permanent (or temporary) bracing members at the same time as assembling the main components.
        • When installing the roof, it is forbidden for workers to walk on the bracing members, purlins, and the ridge of the trusses; to walk on the steel trusses, a platform at least 0.5 m wide with a guardrail at least 1m high must be built.
        • The crane hook can only be detached from the components after they have been securely fixed;
        • For columns, there must be at least four anchor bolts on all sides or after temporary guy ropes have been installed;
        • For trusses, after the temporary bracing members or purlins have been installed with the previously installed and fixed trusses;
        • For crane girders and truss support frames, after at least 50% of the bolts or rivets according to the design have been tightened;
        • For welded structures, temporary bolts are used in all bolt holes.
        • For thin-plate riveted structures, after at least 20% of the holes along the perimeter have been bolted. When bolts or clamps are not used, tack welding is performed with a length of at least 10% of the designed weld length and not less than 50mm.
      • Preventing occupational accidents when assembling reinforced concrete components
        • Before lifting, mark the axis lines and elevations on the components;
        • After installing a column in a socket foundation, if the column is less than 10m long, the base of the column can be temporarily fixed with wooden or concrete wedges;
        • For columns over 10m long, in addition to wedges, guy ropes anchored to the ground or a guide frame placed on the foundation surface must be used;
        • Multi-story building columns can be temporarily fixed with guy ropes or inclined props to the floor, or a guide frame can be used to ensure stability and for adjustment;
        • For structures such as crane girders, floor beams, and roof beams and trusses, after being placed in their designed position, they can be fixed with guy ropes on both sides anchored to the ground or floor; or horizontal bracing can be used, hooked to the previously installed and fixed beam or truss;
        • When lifting wall panels, they must be kept in a vertical position;
        • For floor or roof panels, they can only be assembled after their supporting beams or trusses have been securely fixed;
        • When installing balcony panels (awnings), they must be propped before being fixed;
        • When welding and pouring concrete, the joints connecting the components must be carried out from a work platform on a scaffold, mobile trestle, or hanging platform with a safety rail. Leaning ladders must not be used to perform these tasks;
        • The structures of the upper floor can only be assembled after the lower floor has been completed.

Construction safety document

Construction safety document

d. Occupational safety in masonry work in the construction safety document

The walls of a building are generally built in many different locations, such as below ground when building the foundation, and at height when building the walls of the upper floors.

If workers do not understand the safety measures for masonry work, accidents are very likely to occur. Therefore, they need to understand the potential risks of occupational accidents and the preventive measures.

  • Risks of occupational accidents in masonry work
    • Masonry collapse, the main risks of masonry collapse are:
      • The mortar does not ensure quality in terms of adhesion and strength;
      • When mixing mortar, the proportions of lime, sand, cement, and water are not correct. Improper mixing of mortar results in a non-uniform mixture;
      • The wall is built too high, without buttresses, the mortar joints are not dry, wet from rain…
    • Violation of technical building rules:
      • Laying bricks incorrectly, too many overlapping joints in the layers, misaligned corners;
      • Mortar not completely filling the joints (not full mortar) or mortar being too thick, wet bricks; + The wall is built tilted, not vertical;
      • The building surface is not level; pushing against the wall, hitting the wall with materials;
      • Exceeding the specified height or building too high for each lift;
      • Building a 11cm wall (a single-leaf wall) too long without buttresses;
      • Not covering a newly built wall during rain, causing the mortar to wash out;
      • The built wall encounters unexpected wind, storms, or gusts without timely support…
    • Not providing sturdy and safe means of working at height, such as scaffolding, work platforms, props, or lack of safety railings…
    • Violation of safety rules when transporting materials to the workstation + Tossing or throwing bricks up or down;
      • Dumping bricks en masse from the ground into the foundation pit.
    • Materials or tools falling on people working below
      • Above the work area or walkways below, there are no protective platforms or nets to catch falling objects;
      • No fencing around the structure under construction at height.
    • Workers violating safety rules and labor discipline
      • Walking, standing, or working on top of a wall or pillar;
      • Building in dangerous high places (corners of high floors or edges of high structures,…) without wearing a safety harness…
    • Stacking too many materials on the work platform.
  • Preventive measures for occupational accidents in masonry work
    • Safety when building foundations
      • Before working in the foundation pit, check the condition of the soil walls (vertical or sloped) or the shoring system (if any), or whether materials, bricks, stones, or machinery are placed at the edge of the foundation pit, paying special attention to pits excavated in loose, overly moist soil or near transport routes, which are affected by vehicle vibrations;
      • Do not pile excavated soil or materials around the foundation pit; they must be at least 0.5m away. Do not place heavy machinery or allow vehicles to drive close to the edge of the excavated pit;
      • Mortar, bricks, and stones can be lowered into the foundation pit in sturdy containers and transported by mechanical or manual means;
      • Bricks can be transported using a slide; do not dump or throw bricks and stones into the pit;
      • It is forbidden to work or transport materials over the pit in an area where people are working below without ensuring safety measures;
      • When lifting materials into the pit, lower them slowly, without shaking, jerking, or strong impacts on the material container;
      • It is forbidden to stand under the material container while it is being moved; only approach the container when it has been lowered to about 20-30 cm from the placement point;
      • When building a wall, if the foundation pit is flooded with rain or groundwater, all water must be pumped or bailed out before continuing work;
      • Do not backfill one side of the foundation before the mortar has hardened. For retaining walls, backfilling can only be done after the wall has reached its designed strength;
      • If the foundation pit is backfilled near the foundation of another structure whose footing is higher than the bottom of the backfilled pit, the shoring system should be left in place in the ground.
    • Safety when building walls (excerpt from QCVN 18: 2014/BXD)
      • The condition of the foundation or the previously built part of the wall, as well as the condition of the scaffolding and supports, must be checked before starting construction;
      • When building to a height of 1.5m from the floor or floor level, scaffolding or supports must be installed as required;
      • Materials must be transported to the work platform at a height of over 2m using lifting equipment. The brick-lifting platform must have a guardrail to ensure it does not fall or topple when lifted;
      • When working on an indoor work platform for construction, a barrier or warning sign must be placed outside the building, 1.5m from the base of the wall if building at a height not exceeding 7m, or 2m from the base of the wall if building at a height exceeding 7m;
      • It is not permitted to: Stand on the wall to build; Walk on the wall; Stand on an overhang to build; Lean a ladder against a newly built wall to go up or down; Leave tools or building materials on the wall being built;
      • Do not build more than two floors when the lower floor does not have a beam-floor system or a temporary floor;
      • When building, if there is heavy rain, a storm, or wind of level 5 or higher, the masonry must be covered and supported to prevent erosion or collapse;
      • When a free-standing pillar or gable is completed, it must be covered with a roof during the rainy season;
      • When building and fixing cladding panels at the same time, construction can only be stopped after building past the top edge of the cladding panels;
      • When building overhangs that project more than 20cm from the wall, cantilevered supports must be used. The width of the cantilevered supports must be 30cm wider than the overhang. The cantilevered supports can only be removed when the overhang structure has reached its designed strength.
    • Some notes when building walls:
      • When building a wall 1.2m or higher from the floor or floor level, one must stand on a trestle scaffold with a guardrail. The work platform surface must be 2-3 brick layers lower than the wall surface so that the worker does not have to bend down and to create a protective edge for the worker;
      • For walls 33cm thick or more, scaffolding must be erected on both the inside and outside of the wall;
      • When installing and dismantling protective covers, workers must wear a safety harness;
      • It is forbidden to use the protective cover as scaffolding, to walk on it, or to stack materials on it;
      • It is forbidden to build more than two stories of a house when the middle floor does not have a floor or a temporary floor.
    • Wall openings from the second floor upwards must be covered if a person can fall through;
      • When building a cornice (overhang) that projects more than 30cm from the wall, cantilevered supports must be used. Workers must stand on an external scaffold or a cantilevered scaffold; the work platform must have a safety rail 1m high, and the distance between the rail and the outer edge of the cornice must be at least 60cm;
      • It is forbidden to pass bricks by tossing them up a height of more than 2m;
      • In one day, a single lift of masonry should not be higher than 1.2m.

Construction safety document

5. Occupational safety during the finishing of a structure

a. Occupational safety in plastering work in the construction safety document

  • Occupational safety in plastering work
    • Plastering work includes plastering interior walls, exterior walls, ceilings, cornices, and creating architectural details for the structure. Plastering is mainly done manually. In addition, some construction sites use plaster spraying machines. When working, at many locations, workers have to work at height above the ground or floor levels as the structure rises, with the help of a scaffolding system.
  • Risks of occupational accidents in plastering work
    • Risks of accidents when working at height;
    • Objects can fall, walls can collapse and hit people;
    • Patches of ceiling plaster can fall on the worker’s face due to an overly damp substrate causing the plaster to sag;
    • Supporting machinery and tools can cause accidents;
    • The plaster spray nozzle can be exposed or punctured, causing plaster to spray onto people…
  • Preventive measures for occupational accidents in plastering work
    • Have measures to prevent accidents when working with construction machinery and equipment, and when working at height.
    • Preventing occupational accidents when plastering inside a structure:
      • Interior plastering can only begin after door frames, partitions, ventilation ducts, and other specialized construction and installation work have been completed…;
      • It can only be carried out on all types of scaffolding or trestle scaffolds with sturdy safety railings on all four sides;
      • Hanging ladders can only be used in separate areas with small workloads.
    • Preventing occupational accidents when plastering outside a structure: When plastering on two or more floors at the same time, an intermediate protective platform should be arranged between the people working on the different floors. Workers must be staggered when plastering on different floors.
    • Preventing occupational accidents when using a plaster spraying machine:
      • Unauthorized persons must stay at least 10m away from the machine;
      • Only workers who have been trained in using a plaster spraying machine should be used, as this work requires strict adherence to technical procedures and safety techniques;
      • Machine operators should be equipped with personal protective equipment such as masks, goggles, or gloves…;
      • Before starting work, all parts of the machine must be checked, such as: the nozzle, rubber hose, pressure gauge, safety valve, or signaling system…;
      • While working, always monitor to ensure the plaster hose does not get kinked or coiled. If any abnormalities such as a leaking or cracked hose are noticed, stop work immediately and replace the hose;
      • It is forbidden to stop the supply of plaster to the spray nozzle by kinking the plaster hose;
      • After finishing work, the hose system must be blown clean. The machine’s power must be turned off when cleaning or repairing the machine;
      • Wait until the pressure in the machine has completely dropped before blowing, cleaning, repairing…

b. Occupational safety in tiling and equipment installation in the construction safety document

  • Tiling and flooring work generally require the use of electric power tools to cut or grind tiles…, so the following should be noted:
    • Comply with safety regulations when working with all types of supporting tools and equipment;
    • Adhere to occupational safety regulations on the construction site;
    • Use appropriate personal protective equipment during construction.

c. Painting and whitewashing of structures (excerpt from QCVN 18: 2014/BXD) in the construction safety document

  • Whitewashing, painting, and decorating the exterior of a building must be done from scaffolding as required;
  • Painting skylight frames must be done from specialized scaffolding, and workers must wear a safety harness. Do not walk on the skylight frame;
  • A leaning ladder can only be used for whitewashing or painting small areas at a height of no more than 5m from the floor or ground. At heights above 5m, if a leaning ladder is used, the top of the ladder must be fixed to stable structural parts of the building. Do not lean the ladder against a window frame;
  • The use of whitewashing and oil painting machines must follow regulations;
  • When painting inside a building or using paints containing hazardous substances, workers must be equipped with a respirator;
  • When painting inside a building with paints containing hazardous substances, all doors and ventilation equipment in the room must be opened at least 1 hour before starting work;
  • Do not smoke or perform any work that uses fire or generates sparks in the area where nitro paint is being used. The power must be turned off if there are power lines or operating electrical equipment in the room;
  • Do not allow people to enter a room that has been whitewashed or painted with hazardous substances that are not yet dry and have not been well-ventilated without safety protective equipment;
  • The paint mixing room must be well-ventilated. The lighting and equipment in the paint mixing room must be safe in terms of fire and explosion. Paint containers must be labeled with the name of the material, code, type of solvent, product number, production date, and weight;
  • When using oil for mixing, measures must be taken to prevent the oil from splashing out. Do not fill the cooking container with oil more than 1/4 of its capacity. The oil heating area must be located separately and must comply with current fire prevention and fighting regulations;
  • When removing old paint layers with chemicals, workers must wear rubber gloves and use a long-handled ladle to scoop. The waste solution after removal must be collected in a separate container for disposal according to current environmental protection regulations.
  • Preventive measures for occupational accidents in painting and whitewashing:
    • Workers must be fully equipped with personal protective equipment such as: goggles, hats, masks, and gloves. If the painting room is too enclosed and cannot be ventilated, workers must be equipped with an oxygen tank;
    • In all cases, a local ventilation system such as a fan must be used to ventilate the painting area. The air must be changed at least 2 times per hour;
    • Before working with a paint sprayer, check the rubber hose and test it with a pressure 1.5 times the working pressure;
    • It is forbidden for people to stay in a newly painted room for more than 4 hours.

CHAPTER 2: SAFE USE OF MACHINERY, EQUIPMENT, AND SUPPORTING TOOLS

In construction, various types of machinery, tools, and construction equipment are indispensable. They support quality and on-schedule construction, increase labor productivity, and reduce heavy work for workers. However, not understanding the safety measures and techniques when working with these machines or equipment can lead to a high risk of occupational accidents. Therefore, ensuring occupational safety in the use of construction machinery and equipment is very important.

1. Groups of construction machinery in the construction safety document

Construction machinery and equipment are numerous and diverse, with many types on the list of items with strict occupational safety requirements as specified by the state. They can be classified into the following groups:

  • Foundation and pile construction machinery, such as pile drivers, pile boring machines, pile pressing machines…
  • Earthmoving machinery, such as excavators, bulldozers, soil compactors…
  • Material lifting and lowering machinery, such as cranes or hoists…
  • Material transport machinery, such as automobiles or excavators, loaders…
  • Concrete pouring support machinery, such as mortar mixers, concrete mixers, vibrators…
  • High-pressure gas supply machinery, such as air compressors…
  • Prestressing equipment, such as hydraulic jacks…
  • Electrical machinery, such as generators, transformers, welding machines…

The machines above are those, and the jobs involving them have strict requirements for occupational safety and health. Workers operating these types of machines must attend a separate training course. This textbook only covers safety in construction for handheld equipment and tools.

2. Supporting equipment and tools in construction in the construction safety document

a. General requirements (excerpt from QCVN 18: 2014/BXD) in the construction safety document

  • Handheld tools and equipment must be safe and convenient, moving parts must be maximally shielded, have an instant-off mechanism and not accidentally turn back on, not work beyond the safe speed indicated on the tool, and only start from the lowest speed.
  • Tools and equipment weighing 10kg or more must be equipped with a mechanism for lifting and hanging when in use;
  • Handheld tools and equipment used for striking and chiseling must ensure:
    • The tip is not cracked or has any other damage;
    • The handle is not cracked, broken, has no sharp edges, and must have a suitable length to ensure safety during operation.
  • Tools and equipment supplied to workers must be complete, accompanied by easy-to-understand and easy-to-follow user instructions;
  • Power cords and pneumatic hoses must be buried underground or hung overhead,
  • must not be stretched, twisted, or folded during operation. Power cables, welding cables, and steam hoses must not be placed on top of each other;
  • Only trained and designated persons are allowed to use electrical and pneumatic equipment… Tools and parts of tools must be used according to their designed function; must be in a healthy, alert state and wear full PPE (clothing, hat, glasses, mask, gloves, shoes, boots, safety harness,…). When working at height, a small tool container must be provided; tools and the tool container must be tied with a rope to prevent them from falling and causing an accident;
  • When not in use, handheld tools and equipment must be turned off, packed, and stored neatly and carefully, avoiding falls, breakage, and injury from sharp parts. The sharp parts of tools and equipment must be covered when being moved;
  • Before use: check the safe working condition of the tool, test run it without a load to detect errors, and parts that are or are about to be damaged must be repaired immediately;
  • While working, the worker must stand in a safe, stable position on both feet, use both hands to control the tool, and must not stand on an extension ladder. Clamp the object securely before drilling or tightening a nut. Do not use hands to clean metal shavings, grasp rotating machine parts, or place hands or feet near moving machine parts;
  • The power source must be disconnected when an unusual phenomenon is observed, when there is a power or air outage, when moving the tool, or when stopping work;
  • Only insulated tools or tools made of non-conductive materials may be used near live electrical currents where there is a risk of electric shock.
  • Only non-sparking tools may be used in areas with flammable and explosive dust and vapors;
  • During construction, measures must be taken to prevent the possibility of penetrating structures and causing various materials to be ejected at surrounding people.

b. Risks of accidents when using construction equipment and tools

In construction, various types of handheld equipment and tools are very useful. However, without good awareness, lack of protective equipment, and lack of safe working methods, the following risks of occupational accidents can be considered:

  • Shortcomings in machine management
    • The inspection, repair, and maintenance regime is not in accordance with regulations;
    • Unclear assignment of responsibility for managing and using the machine;
    • Lack of records, history, and instruction manuals for machine installation, use, and maintenance.
  • Poor condition of the machine in use
    • The machine is incomplete or lacks safety mechanisms during use;
    • Damaged machines are not repaired in time;
    • Lack of protective guards or barriers in hazardous areas;
    • The machine is used continuously for a long time;
    • Lack of lighting during construction…
  • Due to the machine operator
    • Not ensuring professional qualifications, such as: not being proficient, inaccurate operations, lack of experience in promptly handling incidents…;
    • Violation of safety rules and regulations, such as using the machine not for its intended purpose or technical capabilities (exceeding capacity, overload, or overspeed…);
    • Not meeting health requirements, such as poor eyesight, hearing loss, or heart disease…;
    • Violation of labor discipline, such as leaving the machine while it is still running, being under the influence of alcohol or beer while operating the machine; handing over the machine to an unauthorized and unqualified person…

Construction safety document

Construction safety document

c. Preventing accidents when using construction equipment and tools

  • There are 5 main principles:
    • Always ensure that this equipment is properly maintained and still in good working condition;
    • Use the right tool or equipment for the job;
    • Carefully inspect the equipment before use, do not use damaged tools; + Use the equipment according to the manufacturer’s instructions;
    • Be provided with and use the accompanying personal protective equipment correctly.
  • Good organization of machine management
    • The head of the unit assigns the unit and individuals to be responsible for managing and using construction equipment and tools, including: Managing records, history, descriptions, technical instructions for safe installation, maintenance, and use; periodic maintenance and repair according to plan.
  • Selection and use of operators must meet the following standards
    • Have a health certificate issued by a competent medical authority;
    • Have a diploma or certificate of professional training issued by a competent authority;
    • Have a card or certificate of occupational safety training;
    • Be fully equipped with personal protective equipment suitable for the job;
    • Be instructed and trained on safety before starting the job…
  • Ensuring good machine quality and safe operation
    • Have full and appropriate safety devices that operate accurately, reliably, and dependably;
    • Inspect and test the durability and reliability of moving parts, mechanisms, and machine, equipment, and tool components before operation;
    • Install protective guards and barriers in hazardous areas;
    • Implement measures to prevent electrical accidents.
  • Some safety measures at the workplace
    • The work area must always be kept clean and tidy so that workers do not trip or fall into construction equipment and tools;
    • When working with equipment that has saw blades or sharp knives, they must be pointed away from the walkway of workers or others working together;
    • For machines that generate sparks, they must absolutely not be used in an environment with gasoline vapor, gas, or coal dust…;
    • When moving equipment to other work locations, do not hold the power cord, hose, or pipe to pull it, and do not jerk it hard;
    • Do not place power cords, hoses, or pipes near heat sources, where there is gasoline or oil, or where there are sharp objects; unauthorized persons are not allowed to approach the equipment;
    • Always maintain body balance and do not wear jewelry while working;
    • Do not try to use equipment that has a malfunctioning part, especially parts related to electricity;
    • Do not let water fall into sockets or plugs. Do not use handheld electrical tools in the rain; Electrical tools and equipment must be grounded, except for double-insulated tools that have been inspected and have a distinguishing mark; Use handheld electrical tools and equipment in areas with a high risk of electrical hazards with a voltage not exceeding 36V. In areas with a low risk of electrical hazards, a voltage of 110V or 220V can be used, and workers must wear insulated boots or shoes and gloves. When using handheld electrical tools and equipment inside metal tanks or wells, a person must be monitored from the outside (excerpt from QCVN 18: 2014/BXD);
    • Use full personal protective equipment during work; + Always ensure adequate lighting at the workplace;
    • Equipment and tools must be wiped clean, and stored carefully;
    • When not in use, they must be stored in a dry, cool place…

Construction safety document
Construction safety document

CHAPTER 3: PREVENTION OF OCCUPATIONAL ACCIDENTS DUE TO FALLS FROM HEIGHT

1. Causes of occupational accidents in construction

According to statistics on occupational accidents collected over many years, accidents from falls from height are the most common, accounting for the highest proportion (20-30%) of all occupational accidents that occur. Among them, fatal falls from height have also consistently accounted for a high proportion of other types of fatal accidents for many years.

Accidents from falls from height not only occur on large, concentrated construction sites and tall buildings but also on small, low-rise, and scattered construction sites. The distribution of accidents at different heights is as follows:

  • Below 5m: 23.4%;
  • From 5 – 10m: 25.8%;
  • Above 10m: 51.6%.

Falls from height account for up to 80% of occupational accidents in construction. Every year, about 60,000 people in the world die from falls from height.

a. Cases of falls from height in the construction safety document

  • Falls from height have occurred in all types of construction work at height, such as: masonry, installation, formwork dismantling, rebar installation, concrete pouring and compacting, assembly of building structures and equipment, transporting materials to height, roofing, and finishing work…
  • Falls from height are most common when workers are working around the perimeter of the building, or on structural parts that protrude from the building (eaves, cantilevers, railings, corridors…) or on the roof (especially sloped roofs), roofs made of brittle materials that are easily broken…
  • Falls from height have occurred at work locations such as: climbing on walls, on assembled structures, on scaffolding, on formwork frames, and rebar to go up and down, walking on the top of beams, top of walls, through windows… Falls when working on ladders, temporary work platforms that collapse or break, or in precarious, dangerous positions without wearing a safety harness, without scaffolding, or safety railings…

b. Main causes of fall from height accidents in the construction safety document

  • Organizational causes, accounting for 20-30% of accidents, such as:
    • Assigning workers who are not qualified to work at height, who are not in good health (pregnant women, people with heart disease, high blood pressure, hearing or vision impairment…) and workers who have not been trained in professional skills and occupational safety, leading to violations of technical procedures, labor discipline, and occupational safety rules.
    • Walking and working in dangerous and unstable positions, such as rotten purlins, asbestos cement tiles…
    • Lack of regular inspection and supervision to detect, prevent, and promptly rectify unsafe working conditions at height.
    • Workers not being trained in professional skills and occupational safety;
    • Lack of personal protective equipment such as shoes, safety harnesses, safety helmets…
  • Technical causes, accounting for 50-60% of accidents, such as:
    • Not using means for working at height such as ladders, various types of scaffolding (trestle scaffold, high scaffold, hanging scaffold, hanging cradle…), safety harnesses, railings, or nets…
    • Using means for working at height that do not meet safety requirements, causing incidents and accidents due to specific or coincidental errors in four stages: Design, fabrication, erection and dismantling, and use.
      • Causes due to design errors: Incorrect determination of the diagram and calculation loads for the actual working conditions. The structural details and connections of the component parts are not suitable for the fabrication capabilities and conditions.
      • Errors due to fabrication: Poor quality materials are used, which are broken, cracked, warped, or rusty… fabrication is not accurate according to the design dimensions; welded connections are not strong.
      • Errors in erection and dismantling: Incorrect dimensions of the spacing according to the design (between columns in both longitudinal and transverse directions; height between floors). Scaffolding columns are placed on a slope, not vertically, causing eccentricity of the vertical acting forces, leading to overstressing; not arranging enough and in the correct positions the anchor points of the scaffolding to the building under construction; scaffolding is placed on a weak foundation, causing settlement; when erecting the scaffolding, workers do not wear safety harnesses, and violate the installation and dismantling sequence.
      • Violations in the process of using scaffolding: Stacking too many materials or a large number of people on the work platform, causing an overload. Not regularly inspecting the condition of the scaffolding to promptly repair and replace damaged parts.
  • In addition to the causes of scaffolding collapse and falls from height, the risk of falling from height when working on scaffolding is also due to the work platform not having a safety rail, no ladder to go up and down between the floor levels on the scaffolding, the scaffolding is located near power lines; workers are working on the scaffolding floors in a vertical line…

Construction safety document
Construction safety document

2. Direction for preventing falls from height in the construction safety document

To prevent and limit falls from height, depending on the nature and characteristics of the construction project, and the specific conditions and capabilities of the construction site, the following directions and preventive measures can be studied and applied:

a. First direction: Limiting and reducing work at height in the construction safety document

To implement this direction, it is necessary to study and change the technological and organizational measures for work at height so that it can be performed at a lower level. This is a proactive direction to prevent falls from height during construction (the fewer people working at height, the lower the probability of falls from height). Some measures can be mentioned as follows:

  • Improving the quality of production and fabrication of assembled components:
    • Ensuring accurate dimensions of fabricated products to avoid having to chisel, trim, or shim components at height during their lifting and installation into the designed position;
    • Completely finishing components on the ground before lifting and installing, such as chiseling off burrs, treating pitted concrete surfaces, removing rust, painting metal structural details….
  • Studying the change of wet joint designs to dry joints in assembled structures made of precast reinforced concrete. This will avoid the stages of installing and dismantling formwork and pouring concrete for the assembly joints at height;
  • Combining formwork and rebar into components, semi-finished products, and using a crane to lift and install them into the designed position. In this way, tasks such as welding, tying rebar, and assembling formwork… can be performed by workers on the ground, which is both convenient for operation and avoids the risk of falling from height;
  • Studying and carrying out the “amplification” of the lifting and assembly structure, from small, individual components into large structures or blocks suitable for the crane’s lifting capacity. This will reduce the number of times components are lifted and assembled, and also reduce the number of assembly joints at height;
  • Studying and applying structural slinging devices with automatic or semi-automatic locks to release the structure from the crane hook. Thanks to this device, workers can stand on the ground, floor, or in a safe position to release the crane hook from the structure, without having to climb up;

Construction safety document

  • Organize construction reasonably, so that workers have to change their working position at different heights as little as possible during a work shift. Utilize lifting equipment such as cranes, hoists, and winches… to transport materials. Minimize the manual transport of materials and components to height (carrying, shouldering, etc.).

The above are some measures within the direction of preventing falls from height by limiting and reducing work at height. This is a positive preventive direction: “to avoid falling from height, do not go up.”

However, this direction is only mentioned in a general way within a limited scope, referring to experiences from abroad or from advanced construction sites in the country that have applied it. To implement it, it is necessary to conduct in-depth research on specific organizational and construction technology measures, depending on the actual conditions and capabilities in terms of technical level, materials, equipment, and materials of the construction unit.

b. Second direction: Implementing measures to ensure safety and prevent falls from height

In cases where workers must work at height, it is essential to implement safety measures. These measures must be implemented as follows:

  • Specify specific standards for people working at height, such as: health, occupational safety training when working at height…;
  • Develop and disseminate specific rules and regulations on safety work and conduct propaganda and occupational safety training for workers working at height;
  • Implement specific fall prevention measures suitable for each type of work, each scope and location of work at height, including:
    • General safety measures when working at height;
    • Equip with personal protective equipment when working at height;
    • Fall prevention measures when carrying out construction and installation work at height;
    • Inspect, supervise, urge, remind, and handle violations of safety work.

Construction safety document

3. General requirements when working at height (excerpt from QCVN 18: 2014/BXD) in the construction safety document

  • Construction is not permitted without a full set of design documents (documents) for technical and organizational construction measures, which must show the technical measures to ensure occupational safety and fire and explosion prevention;
  • Workers working at height and in deep tunnels must have a tool bag. Do not drop or throw any kind of materials, tools, or equipment from a height;
  • Workers working on the construction site must use the correct and sufficient personal protective equipment as required;
  • When working at height (from 2m or more) or not yet at that height, but there are dangerous obstacles below the work area, safety harnesses for workers or protective nets must be provided. If it is not possible to build a work platform with a safety rail, workers are not allowed to work without wearing a safety harness;
  • Do not work on two or more floors at the same time in a vertical line, if there is no safety protection for the workers below;
  • Do not work on scaffolding, chimneys, water towers, power poles, bridge piers or beams, or roofs of two-story buildings or higher during heavy rain, thunderstorms, storms, or winds of level 5 or higher;
  • After each storm, strong wind, or after a long break in construction, the safety conditions must be re-checked before resuming construction;
  • There must be adequate ventilation measures and means to prevent toxic gases or collapse when working in deep wells, underground tunnels, or in enclosed containers. Before and during work, there must be a strict inspection regime, with a person on duty outside to ensure regular communication between inside and outside and to provide timely first aid in case of an accident;
  • On the construction site, a full lighting system must be arranged on traffic routes and construction areas at night. It is not allowed to work in unlit places. Local lighting at the workplace should be from 100 to 300 lux, and general lighting from 30 to 80 lux;
  • There must be a lightning protection system to protect the entire construction site during construction;
  • The construction site must have an occupational safety logbook and record all incidents, accidents, and remedial and handling measures during construction;
  • On the construction site, all work areas must be kept neat and tidy. Equipment and tools must always be placed in their designated places. Waste and surplus materials must be collected regularly…;
  • There must be a solution for moving surplus materials and waste from a height (over 3m). Do not dump surplus materials and waste from a height when the area below is not fenced off, has no warning signs, and has no guards;
  • Insulating materials stacked in piles must not be higher than 1.2m and must be stored in a closed, dry warehouse;
  • Steel pipes with a diameter of less than 300mm must be stacked in layers and not higher than 2.5m. Steel pipes with a diameter of 300mm or more, and all types of cast iron pipes, must be stacked in layers, not higher than 1.2m, and must have secure support measures;
  • Steel plates and structural steel must be stacked in piles not higher than 1.5m. Small-sized types should be stacked on racks with a similar height; the load of steel stacked on the rack must be less than or equal to the permissible load of the rack;
  • Logs must be stacked in piles, with dunnage underneath, must have stakes on both sides, and must not be higher than 1.5m. Sawn timber must be stacked in piles not higher than 1/2 the width of the pile; if stacked in alternating horizontal and vertical layers, it must not be higher than the width of the pile, including the thickness of the dunnage layers.
  • Measures must be taken to ensure the safety of people and property (such as fencing, posting warning signs, or making canopies…) in hazardous areas where objects may fall freely from a height. The limits of this hazardous area are determined according to the following table:
Height from which objects may fall (m) Hazardous zone limit (m)
For a building or structure under construction (from the outer perimeter) For the load movement area (from the horizontal projection of the largest dimension of the moving load when it falls)
Up to 20 5 7
From 20 to 70 7 10
From 70 to 120 10 15
From 120 to 200 15 20
From 200 to 300 20 25
From 300 to 450 25 30

 

4. Preventive measures for occupational accidents due to falls from height in the construction safety document

a. Organizational measures in the construction safety document

  • Requirements for people working at height
    • Must be 18 years of age or older;
    • Have a health certificate issued by a competent medical authority;
    • Must undergo a health check-up at least once a year;
    • Pregnant women, people with heart disease, circulatory problems, hearing loss, or poor eyesight are not allowed to work at height;
    • Have a certificate of occupational safety training confirmed by the project manager;
    • Be fully equipped with personal protective equipment suitable for the working conditions as required;
    • Strictly adhere to labor discipline and occupational safety rules when working at height;
    • Do not drink alcohol, beer, or smoke before or during work; No horseplay or climbing over railings; Do not wear slippers, clogs, or high heels while working…;
    • Workers must have a personal tool bag and equipment. Do not throw or drop any kind of tools, equipment, or any object from a height;
    • Work should be arranged reasonably so that workers do not have to walk or move their work position many times during a work shift.
  • Implementing safety supervision and inspection when working at height
    • Technical officers, production team leaders, and occupational safety officers are responsible for regularly supervising and inspecting, detecting, and promptly preventing unsafe phenomena at the workplace, such as the condition of scaffolding, work platforms, ladders, safety railings, and other means of working at height;
    • Regularly check and guide the correct and sufficient use of personal protective equipment such as safety harnesses, safety helmets, shoes, and work clothes…;
    • If a dangerous situation is detected, such as a weak work platform or overloaded scaffolding, work must be stopped and immediate repairs and corrections must be made. Work can only resume after safety is ensured;
    • Regularly monitor and remind workers to strictly comply with labor discipline and occupational safety rules when working at height. In cases where workers continue to violate occupational safety rules after being reminded, they must be retrained and retested on occupational safety, or handled according to regulations.

b. Technical measures in the construction safety document

  • Use of personal protective equipment (this section is covered in the next chapter 4)
  • Use of various types of scaffolding during construction (covered in section 4.3 of this chapter)
  • Safety for ladders (excerpt from QCVN 18: 2014/BXD)
    • Ladders must be placed on a flat, stable surface and securely chocked. A leaning ladder must not be placed at an angle greater than 60° or less than 45° to the horizontal. If a ladder is placed contrary to this regulation, someone must hold the ladder, and the base of the ladder must be securely chocked;
    • When extending a ladder, it must be securely tied with a rope; the top of the ladder must be anchored to the structure;
    • Before working on a folding ladder, a rope must be used to prevent the ladder from spreading apart;
    • Before using a ladder, check its general safety condition. For a new ladder or a ladder that has not been used for a long time, it must be tested with a load of 120daN before use;
    • Before allowing someone to climb a ladder, re-check the ladder chocks and the ladder’s support position;
    • Do not hang heavy objects exceeding the permissible load on the ladder while someone is working on it. Do not use a folding ladder as scaffolding or a support.

Construction safety document

    • Do not use ladders longer than 5m; extend a 2-rung ladder if the ladder is 3m long and a 3-rung ladder if the ladder is 5m long;

Construction safety document

    • Have a measure to securely fix the ladder and have one person work on the ladder, limiting the carrying of equipment and tools;
    • When working on a ladder, do not reach too far; when ascending and descending, face the ladder and hold on to the two side rails or handrails with both hands;
    • Do not use a metal ladder to work in conditions where an electrical wire could touch the ladder;
    • Regularly wipe off mud, oil, and grease, and check for and eliminate any damage.
  • Ventilation to ensure safety (excerpt from QCVN 18: 2014/BXD)
    • Underground structures must ensure ventilation with appropriate ventilation equipment. Single-entry tunnels deeper than 10m must have forced ventilation.
    • Ventilation in underground structures must always ensure:
      • The oxygen content in the air is not less than 20% by volume;
      • The content of other toxic gases is below the permissible limit;
      • The amount of air required for one person’s respiration is not less than 4m³/min; + The maximum temperature does not exceed 30°C.
    • The power source for the main fan must be supplied from two independent sources (one active, one backup).
    • Main ventilation fan:
      • Must have a mechanism to reverse the airflow within 10 minutes in case of an incident and ensure 60% of the standard airflow compared to normal operation;
      • Must have a backup motor; if there is methane gas, there must be a backup fan.
    • If toxic gases or methane appear, workers must be fully equipped with protective equipment and tools according to the prescribed regulations and other inspection and testing equipment;
    • If a large amount of toxic gases appear or the ventilation system fails while working, work must be stopped immediately, and everyone must evacuate to a safe place. Work can only be resumed after the situation has been resolved and safety is ensured.
  • Installation and use of electricity in construction (excerpt from QCVN 18: 2014/BXD)
    • When installing, using, and repairing electrical equipment and the construction power grid on the site, in addition to the regulations in this Standard, the regulations in QCVN QTĐ-5: 2009/BCT, QCVN QTĐ-06: 2009/BCT, QCVN QTĐ-07: 2009/BCT, QCVN 01: 2008/BCT and other current regulations on electrical engineering and electrical safety must also be followed;
    • Electricians as well as operators of electrical equipment must be trained and certified as meeting the requirements for electrical safety. Electricians working in any area on the construction site must be familiar with the power supply diagram of that area. Electricians on duty at electrical equipment with a voltage up to 1000V must have an electrical safety level of 4 or higher;
    • On the construction site, there must be a power grid diagram, a main circuit breaker, and sectional circuit breakers to be able to cut off power to the entire site or to each area of the building when necessary. There must be two separate systems for power and lighting;
    • The bare live parts of electrical equipment (conductors, busbars, contacts of circuit breakers, fuses, terminals of electrical machines and tools…) must be fully insulated with insulating material or placed at a height that ensures safety and convenience for operation. The ends of bare conductors and cables must be insulated, fully covered, or hung high. For live parts left exposed as required by the design or by the structure, they must be hung high, have a barrier, and be marked with a warning sign;

Construction safety document

    • The conductors used for construction in each area of the building must be insulated wires; they must be installed on sturdy poles or supports; they must be at a height of at least 2.5m above the construction floor and 5.0m in areas with vehicle traffic. Electrical wires with a height of less than 2.5m from the ground or work platform must be rubber-insulated cables. Electrical cables used for mobile construction machinery must be wound on a drum or run in a cable trench. Electrical cables must not be dragged on the ground, or be run over by vehicles, or have other structures placed on them;
    • Lighting fixtures with a voltage greater than 36V must be hung at least 2.5m above the work platform;
    • Do not use power grids, distribution mechanisms, electrical panels, and their branches that are in the process of installation to replace temporary power grids and electrical equipment used on the construction site. Do not allow construction power lines and welding cables to come into contact with the live parts of the building’s structures;
    • Do not remove and install light bulbs without cutting off the power. If the power cannot be cut off, the worker doing this must wear insulating gloves and protective goggles;
    • Do not use fixed lighting fixtures as handheld lights. In areas with electrical hazards, lights with a voltage not exceeding 36V must be used. Handheld lights must have a metal guard to protect the bulb, the cord must be rubber-insulated, and power must be supplied through a socket. Sockets and plugs for voltages not exceeding 36V must have a structure and color that distinguishes them from sockets and plugs for higher voltages. Lights for illuminating the workplace must be placed at a suitable height and angle to avoid glare from direct light from the lamp;
    • It is not allowed to use power sources to make protective fences for the construction site;
    • Handheld electrical tools (electrical tools, portable lights, safety step-down transformers, frequency converters…) must be checked at least once every 3 months for any live casing, and for the condition of the protective ground wire; they must be checked at least once a month for the insulation of the power cord, power source, and any exposed electrical parts. For portable transformers, in addition to the above points, the short circuit of the high-voltage and low-voltage windings must also be checked;
    • Do not use an autotransformer as a power source for lighting and handheld electrical tools with a voltage not exceeding 36V;
    • Only connect electric motors, electrical tools, lighting, and other equipment to the power grid using the specified accessories. Do not twist or splice the ends of electrical wires.

c. Use of various types of scaffolding in construction in the construction safety document

  • Terms and concepts
    • Scaffolding is a temporary structural system placed on a solid foundation or can be hung, anchored, or supported against a structure to create a workplace for workers at high positions relative to the ground or a fixed floor.
  • Classification of scaffolding
    • According to “Vietnam Construction Standard TCXDVN 296: 2004,” 15 types of scaffolding are classified. However, depending on the purpose of use, we can classify them into the following 07 common types of scaffolding:
    • Cantilevered beam scaffolding: Scaffolding with a work platform placed on cantilevered beams from within a wall or on the surface of a building. The inner end is securely anchored to the building or structure.

Construction safety document

    • Prefabricated tubular steel frame scaffolding: A system of metal tube frames (scaffold legs), assembled together with bracing members.

Construction safety document

    • Tubular steel scaffolding and coupler assembly: A scaffolding system constructed from steel tube members such as standards, ledgers, transoms, and bracing members; with base plates for the standards and special couplers to connect the standards and other members.

Construction safety document

    • Suspended beam scaffolding: A work platform placed on two beams, suspended by cables.

Construction safety document

    • Continuous suspended scaffolding: A work platform placed and hooked onto two parallel horizontal steel cables, with the ends of the cables securely connected to the structure.

Construction safety document

    • Single-post scaffolding: A work platform placed on horizontal beams with the outer end placed on longitudinal beams connected to a row of single columns or standards. The inner end of the horizontal beam is anchored into or onto the wall of the building.

Construction safety document

    • Multi-level suspended scaffolding: Scaffolding with work platforms at different elevations, placed on the same support system. This system can be suspended from two or more points.

Construction safety document

  • General requirements for using scaffolding (excerpt from QCVN 18: 2014/BXD)
    • All types of scaffolding and supports must be designed, constructed, erected, accepted, and maintained to ensure safety. Pay attention to the instructions, regulations, and technical requirements recorded on or attached to the manufacturer’s certificate for specialized scaffolding;
    • Scaffolding, supports, and ladders must not be used for purposes other than their intended function. Scaffolding and supports assembled from different types or forms, or using multiple types without a separate design, must not be used;
    • Do not prop scaffolding on an inclined surface without technical measures to prevent the prop from slipping;
    • Scaffolding and supports must not be used when:
      • Made of materials that do not meet the technical requirements according to the applicable standards;
      • They do not meet the technical requirements and occupational safety conditions stated in their design or manufacturer’s certificate;
      • They are deformed, cracked, worn, rusted, or have missing parts;
      • The gap between the work platform and the wall of the building or structure is greater than 5cm during construction and greater than 20cm during finishing;
      • The distance from the edge of the working limit of the scaffolding or support to the adjacent edge of a transport vehicle is less than 60cm;
      • The scaffolding columns and support frames are placed on an unstable foundation, with the possibility of slipping, collapsing, or placed on parts or structures of a building or structure without being fully considered and calculated to ensure stable load-bearing for that part or structure and for the scaffolding columns and support frames;
    • Do not stack loads on scaffolding or supports outside the designated locations (where a sign indicating the permissible load is placed above) or exceed the load according to its design or manufacturer’s certificate. Do not stack or store any type of load on the ladders of the scaffolding or the work platform;
    • When the scaffolding is higher than 6m, at least two work platforms must be built, including the upper working platform and the lower protective platform. When working on two platforms at the same time, there must be a protective platform or net between the two platforms. Do not work on two work platforms in the same bay at the same time without ensuring safety measures;
    • When the scaffolding is higher than 12m, a staircase must be built in one bay of the scaffolding. The slope of the staircase must not be greater than 60°. The opening in the work platform for access must have a safety rail on all three sides;
    • The width of the work platform of the scaffolding must not be less than 1m. When transporting materials on the work platform with a handcart, the width of the platform must not be less than 1.5m. The wheel path must be paved with planks; the ends of the planks must be tight and securely connected to the work platform;
    • The wooden planks for the work platform must not be rotten, worm-eaten, or cracked, and must be designed to ensure load-bearing capacity and stability;
    • When a work platform is required by regulation, it must have a railing at least 1m high and at least 2 horizontal bars capable of preventing people from falling;
    • Walkways under scaffolding and supports must have overhead protection;
    • Scaffolding and supports near excavated pits, roads, and within the operating range of cranes must have measures to prevent the excavated pit walls from collapsing or transport vehicles from colliding and causing the scaffolding or supports to collapse or break;
    • When erecting and using scaffolding and supports near power lines (less than 5m, including low-voltage lines), very strict measures must be taken to ensure electrical safety for workers;
    • On scaffolding and supports where lighting is installed and used, and electricity-consuming equipment is used, the regulations must be followed;
    • Scaffolding and supports up to 4m high can only be put into use after being accepted by a technical officer and recorded in the construction log; if higher than 4m, they can only be used after being accepted according to quality management regulations;
    • For slip forms, work platforms, protective railings, ladders, and windbreaks must be securely connected to the formwork system. The steel ties supporting the jacks must be designed, and the part of the tie above the concrete block must be braced to ensure stability. The jacks and lifting equipment must be equipped with a lock or an automatic anti-fall device;
    • Every day, before starting work, the technical officer must re-check the condition of all structural parts of the scaffolding and supports. While working, any worker who detects a dangerous defect in the scaffolding or supports must stop working and report to the technical officer to carry out supplementary repairs;
    • When construction on scaffolding or supports is suspended for a long time (over one month), if work is to be resumed, it must be re-accepted according to regulations;
    • The dismantling of scaffolding and supports must be carried out according to the instructions in the design or manufacturer’s certificate. The dismantling area must be fenced off, with signs prohibiting people and vehicles from passing. Do not dismantle scaffolding and supports by pulling them down;
    • Do not erect, dismantle, or work on scaffolding or supports during heavy rain, thunderstorms, or winds of level 5 or higher. When the rain stops, if work is to be resumed, the scaffolding and supports must be re-checked according to regulations, and measures must be taken to prevent slipping and falling;
    • When erecting and dismantling steel scaffolding near power lines (less than 5m), the regulations must be followed;
    • When erecting scaffolding higher than 4m, a lightning protection system must be installed according to the design. Except in cases where the scaffolding is erected within the protected area of an existing lightning protection system. (According to TCVN 296:2004, scaffolding is calculated with a load of: Heavy 375kg/m², medium load 250kg/m², light load: 125kg/m²).

Construction safety document

CHAPTER 4: PERSONAL PROTECTIVE EQUIPMENT

1. Concept and principles of use and maintenance in the construction safety document

  • Concept (according to Circular No. 04/2014/TT-BLDTBXH)
    • Personal protective equipment (PPE) are necessary tools and means that workers must be equipped with to use while working or performing tasks to protect their bodies from the effects of dangerous and harmful factors arising in the labor process, when technological, equipment, and technical safety and hygiene solutions at the workplace cannot completely eliminate them.
  • Principles of using personal protective equipment
    • The employer must organize instruction for workers to proficiently use appropriate personal protective equipment and must strictly inspect its use.
    • For specialized personal protective equipment with high technical requirements, the employer must inspect it to ensure quality and specifications before issuing it, and also periodically inspect it during use and keep a log; do not use equipment that does not meet technical requirements or has expired.
    • A person equipped with personal protective equipment must use that equipment according to regulations while working.
    • Workers do not have to pay for the use of personal protective equipment. The employer is responsible for re-equipping workers with personal protective equipment when it is lost, damaged, or has expired. In cases of loss or damage without a valid reason, the worker must compensate according to the establishment’s labor regulations.
  • Principles of maintaining personal protective equipment
    • The employer is responsible for arranging a place to store and maintain personal protective equipment according to the instructions of the manufacturer. Workers are responsible for taking care of the personal protective equipment they are issued.
    • Personal protective equipment used in unhygienic places, which are prone to poisoning, infection, or radiation contamination, must, after use, be cleaned, decontaminated, sterilized, and de-radiated by the employer to ensure hygiene and safety standards for the workers, the surrounding environment, and must be periodically inspected.

2. Personal protective equipment commonly used on construction sites

  • Protective helmet
    • This is a type of personal protective equipment, provided to workers to protect their heads. Hard hats (hard plastic hats) are usually provided to workers in industries such as mining, construction, metallurgy, telecommunications… Hard hats help protect the worker’s head from falling objects or from falls while working; in addition, they can protect the head from the effects of chemicals, electricity…
    • Structure: Hard hats are usually made of synthetic plastic and have 3 main parts:
      • The shell;
      • The inner part (suspension, connecting parts);
      • The chin strap.

    • Selection when using
      • When buying a helmet:
        • request the seller to provide a test report to determine the quality of the helmet. If buying a foreign-made product, request a catalog and clearly state the product quality standard number.
      • When using:
        • Check the helmet; if any are cracked, have a broken strap… discard them and do not use them.
        • When wearing the helmet, adjust the suspension to fit snugly on the head and have a certain distance from the underside of the shell. Wear the helmet straight and fasten the chin strap tightly under the chin.
    • Maintenance: Keep it clean, store it in a dry place, and avoid dropping, breaking, and impact.

  • Shoes and boots on the construction site
    • Shoes and boots for the construction site are intended to protect the worker’s feet during work, and can therefore prevent or limit:
      • A heavy object suddenly falling on the foot or rolling onto the foot;
      • Trips and falls during work;
      • Stepping on a nail or sharp object…
    • Structure: Shoes and boots on the construction site are usually made of leather, rubber… the toe cap and sole are made of steel or composite, which is lightweight, highly durable, and flexible for the feet during work.
    • Features: Oil and grease resistant, waterproof, impact resistant, puncture resistant, slip resistant, shock resistant, and anti-static to ensure safety on the construction site.
  • Safety harness in the construction safety document
    • This is a type of personal protective equipment, provided to workers to protect against falls from height when workers are working at height. Therefore, the safety harness must be of good quality and be regularly inspected before use.
    • There are two types of safety harnesses
      • Regular safety harness: Has a basic structure, consisting of a waist belt, lanyard, buckles, and hooks. This type of belt is lightweight and easy to use, but has the disadvantage of limiting the worker’s range of motion.
        • The waist belt and lanyard are usually made of synthetic fibers. + The hooks and buckles are made of steel.
        • To increase safety and provide comfort, the waist belt is also fitted with a padded belt.
        • The lanyard is usually about 1.2 to 1.8m long.
      • This type of safety belt is commonly used in many jobs at height in the construction, telecommunications, and electricity industries, such as: structural assembly, repair, or replacement of damaged parts on high poles…
        • Safety belt with a protective mechanism: fall height control and positioning lanyard. In terms of structure, in addition to the main parts like a regular belt, this type of belt also has a fall height control mechanism and a positioning lanyard. The fall height control mechanism is located on the positioning lanyard; it is both a place to attach the safety harness and is movable on the positioning lanyard, serving to control the fall height. With this structure, the user of the safety harness can expand their range of motion and work in places where there is no structure to hook the safety harness to.
        • Safety belt with additional leg and shoulder straps. This supplementary structure is securely connected to the waist belt. In the event of a fall, the resulting jerk force is distributed evenly over many parts of the body, making the worker safer.
    • How to use and maintain
      • Carefully observe the work area and find a safe place to attach one end of the belt.
      • Fasten the safety belt around the body.
      • Attach the hook at the other end of the belt to the bracing, railing…
      • The safety harness, as well as any extension lanyards, must be tested for strength with a load of 300daN (300kg) for 5 minutes before first use; if it is safe, it can be issued to workers. Every 6 months, or if there is any doubt about its quality (deterioration, cracks due to friction…), it must be re-tested with the above load by hanging a weight or using a specialized testing device;
      • Check for fraying, breakage, and the connections and hooks of the safety harness with a static load of 300kg (225kg for old harnesses), or with a dynamic load of 100kg;
      • The safety harness must be securely attached above and there must be no obstacles below;
      • The safety harness is used when working at a height of < 6m. If the height is 6m or more, a safety net must also be used;
      • When inspecting and using, monitor the condition of the safety harness, and record the test date, test load, and good/bad comments in a logbook;
      • Note: the attachment point must be sturdy and able to withstand the load of the body.
      • Maintenance: after finishing work, it must be coiled neatly, kept safe and clean, in a dry place, away from heat and direct sunlight.

  • Protective gloves in the construction safety document
    • This is a type of personal protective equipment, provided to workers to ensure the ability to protect their hands from the effects of dangerous and harmful factors, to prevent corrosion from various chemicals, oil, and grease that can damage the hands, to prevent electric shock, to protect against vibration, and to protect hands from acids… Safety gloves must meet the following requirements:
      • Protect against the effects of dangerous and harmful factors for the worker’s hands;
      • Not affect the worker’s movements;
      • Easy to use; easy to maintain and clean.
  • Dust mask in the construction safety document
    • This is a type of personal protective equipment provided to workers to protect their respiratory system from various types of dust or toxic air.
    • Currently, there are many types of masks on the market made of cotton fabric, so the cost is low. However, the dust filtering capacity of these types of masks is often not high, and it is difficult to filter out dust smaller than 5mm, which can easily cause pneumoconiosis. Therefore, a two-layer fabric mask must be used, with a layer of synthetic cotton or activated carbon in between, and an aluminum nose clip to prevent dust from entering through the gap at the nose.
    • Using a dust-filtering mask is easy, convenient, and highly cost-effective, so many workers are willing to use it.
  • Earplugs and earmuffs in the construction safety document
    • This is a type of personal protective equipment, provided to workers to protect their hearing from the effects of noise. There are two main types: earplugs and earmuffs.
    • Earplugs: usually made of plastic, foam plastic, or cotton. They are cylindrical, about 0.8 – 1cm in diameter, and 4cm long. They have low noise reduction capabilities and are widely equipped and used in textile factories.
    • Earmuffs: Have a two-layer structure: the outer layer is a hard plastic, and the inner layer is a foam pad. When worn, the earmuffs fit snugly over the ears, preventing the effects of noise on the worker. Earmuffs have good noise reduction capabilities at high frequencies…

CHAPTER 5: SIGNAL COLORS AND SAFETY SIGNS

1. Signal colors – Function and application regulations in the construction safety document

  • The safety signal colors are specified as follows: red, yellow, green, blue
    • The meaning of the signal colors:
SIGNAL COLOR BASIC MEANING OF THE SIGNAL COLOR CONTRASTING COLOR
Red Prohibition White
Immediate danger
Firefighting equipment
Yellow Caution Black
Warning
Warning of potential danger
Green Instruction White
Order
No danger
Blue Indication White
Guidance
Information

 

  • The red signal color is applied to
    • Prohibition signs.
    • Symbols and text on fire safety signs.
    • The shut-off mechanisms of equipment, including emergency shut-off mechanisms.
    • The inner surface of machine casings or boxes with lids and internal drive mechanisms, and the inner surface of the lids of those casings or boxes.
    • The handle of an emergency pressure release mechanism.
    • The casing of oil-immersed electrical switching equipment.
    • Firefighting technical means such as: fire water pumps; the starting mechanism of firefighting equipment; smoke exhaust pumps; fire alarms; fire extinguishers; the wooden handles of firefighting tools; etc…
    • Signal lights indicating a violation of safety conditions.
    • The border surrounding a white board used to mount firefighting tools and fire extinguishers. The width of this red border is from 30 to 100mm.
  • The yellow signal color is applied to
    • Caution and warning signs.
    • Parts of building structures that pose a risk of injury to people, such as: low beams; bumps and depressions on the floor (pits, protruding bars, etc.); indistinct stair edges; edges of ramps; places with a risk of falling (edges and corners of loading docks, loading trays, unfenced areas, edges of openings, edges of pits, etc.); edges of narrow passages; indistinct props; joints, columns, pillars, and pedestals in locations within the factory with high traffic intensity, the boundary edges of roads and transport routes in the production area, etc…
    • Parts of production equipment that can be dangerous to people, such as: exposed moving parts (flywheels, moving machine tables, etc.); edges of guards that do not completely cover moving parts (guards for grinding wheels, milling cutters, gears, chain drives, etc.); edges of press heads or stamping heads; edges of the hammer head of a power hammer; railings at high workplaces; technological accessories hanging from the ceiling or on the wall that encroach on the workspace.
    • Parts of the transport system within and between workshops; lifting and transport equipment and road construction machinery; control cabins and railings of cranes; rotating control cabins; the side surfaces of the lifting table of a lift; safety guard beams and the sides of electric carts, forklifts, wagons, the lower part of the turntable of an excavator; tower cranes, assembly cranes, and mobile cranes with clamshell buckets; the outside of the side edges of the bucket of an excavator; the casing of a crane hook.
    • Permanent and temporary fences; fences marking the boundaries of hazardous areas; openings in floors; openings of wells; openings of pits. Permanent or temporary fences of stairs, floors under construction, and balconies. Places where there is a risk of falling from height.
    • Mobile equipment used for assembly work or its parts; parts of slinging equipment; the moving part of a tipper, lifting beam, or lift; the moving part of a lifting cage and ladder.
    • Containers for hazardous and toxic substances are painted with a warning of danger in the form of a yellow band around them, 50 to 150mm wide depending on the size of the container.
    • The boundary line of the path to an escape route (main or backup). This boundary line is marked in yellow or white, 50 to 100mm wide, on the floor, and must be durable and not easily erased.
  • The green signal color is applied to
    • Instructional and mandatory signs
    • Doors and electric light signal panels (white text on a green background); emergency exit doors (main or backup); decompression chamber doors and signal lights.
  • The blue signal color is applied to:
    • Indication signs
    • Guidance
    • Information

2. Shape, color, size, and function of safety signs in the construction safety document

  • Regulation of 4 groups of safety signs, presented in Table 2

Construction safety document

CHAPTER 6: FURTHER REFERENCE

1. Group 3 Safety Training and Certification Services

Occupational Safety Training for Group 3

Occupational Safety Training for Group 3

99,000 ₫

2. Group 3 Occupational Safety Test

3. Price List for Occupational Safety Training Services

4. Download the document

LÊ THẾ QUÝ
LÊ THẾ QUÝ

Click here to view information about Occupational Safety and Health Training Instructor

Leave a Reply

Your email address will not be published. Required fields are marked *