Occupational Safety Training Document for Food Processing

DOWNLOAD THE OCCUPATIONAL SAFETY DOCUMENT SET (6 GROUPS, OVER 300 INDUSTRIES)

The document of the occupational safety training course in food processing helps workers equip themselves with safety knowledge and prevent hazards during food processing.

INTRODUCTION

The quality and hygiene of food safety are directly, daily, regularly, continuously, immediately, and long-term related to human health and have a lasting impact on the nation’s genetic lineage. The use of food that does not meet quality or hygiene standards can lead to acute or chronic poisoning. Foodborne infectious diseases and poisoning caused by contaminated food and beverages sometimes accumulate over time and cause outbreaks. Furthermore, food poisoning affects socioeconomic development as well as national and international political security.

According to the World Health Organization (WHO), “More than 200 diseases are transmitted through food; millions of people become ill every year and many die due to unsafe food consumption. Diarrheal diseases kill about 1.5 million children each year, and most of these diseases are believed to result from contaminated food or water.”

In Viet Nam, the issue of food hygiene and safety has become a top concern at all levels, sectors, and in society as a whole. According to the Food Safety Department’s report, in six years (2007–2012), there were 1,095 cases of food poisoning nationwide, with a total of 36,275 affected people and 264 deaths. In 2013, the whole country recorded 139 food poisoning incidents with 4.7 thousand people affected and 26 deaths. It can be seen that food poisoning cases occur not only individually but also collectively. Analysis of 927 food poisoning cases recorded from 2007–2011 shows that cases occurring in collective kitchens accounted for 12.7% to 20.6% of total cases each year.

At present, the demand for food processed in collective kitchens is very high due to its convenience for consumers. This type of catering service is common in areas with large numbers of workers, such as industrial companies or school canteens. With 12 industrial zones spread across various regions, collective kitchens in export processing zones serve a large number of meals for workers—from several hundred to several thousand meals per day. Therefore, if food poisoning occurs, many people will be affected simultaneously, mainly those who belong to the main labor force—an important group of individuals that society cares deeply about.

1. Determine the percentage of people directly involved in food processing in collective kitchens at export processing zones, schools, hospitals, and food production or business establishments who have proper knowledge and practices of food hygiene and safety.
2. Determine the percentage of collective kitchens at export processing zones, schools, hospitals, and food production or business establishments that meet food hygiene and safety conditions as stipulated in Decision No. 4128/2001/QĐ-BYT.
3. Determine the percentage of foods containing borax or formaldehyde in collective kitchens at export processing zones, schools, hospitals, and food production or business establishments.

---

CHAPTER I: THE SITUATION OF FOOD SAFETY IN COOKING, FOOD PROCESSING, AND SANITATION CONDITIONS IN COLLECTIVE KITCHENS

I. The situation of food safety in cooking and food processing at collective kitchens

1. Concepts in the food processing safety training material

• Food: A product that humans consume through eating or drinking, either raw or processed, and preserved. Food does not include cosmetics, tobacco, or substances used as pharmaceuticals.
• Food hygiene and safety: According to the Food and Agriculture Organization (FAO) and the World Health Organization (WHO): “Food hygiene and safety ensures that food does not cause harm to the health or life of consumers, is not spoiled, and does not originate from diseased animals or plants that may cause illness in humans.” In Vietnam, legal documents and official materials define food hygiene and safety as ensuring that food is not harmful to human health or life during use, that it is not spoiled, does not contain physical, chemical, or biological agents or chemicals exceeding permissible limits, and is not derived from diseased animals or plants that may be harmful to human health.
• Conditions ensuring food safety: These are technical standards and other regulations concerning food, food production, business establishments, and food-related activities, issued by competent state management agencies, to ensure that food is safe for human health and life.
• Collective kitchen: A facility that prepares and cooks meals for a group of many people (usually 30 or more) either on-site or elsewhere.
• Collective canteen or collective kitchen: A building used for collective dining, including food preparation and cooking areas.
• Food business: Refers to conducting one, several, or all activities such as introducing, preserving, transporting, or trading food.
• Food service establishment: A facility that prepares food, including food stalls, ready-to-eat food outlets, restaurants, pre-packed meal preparation facilities, canteens, and collective kitchens.
• Food contamination: The presence of agents that pollute food and cause harm to human health and life.
• Food poisoning: An illness caused by consuming food contaminated with bacteria, bacterial toxins, or other harmful substances.
• Food poisoning outbreak: An acute poisoning incident involving two or more people showing signs of poisoning after consuming the same food at the same time and place. Even a single fatal case is also considered a food poisoning outbreak.

2. Conditions ensuring hygiene and food safety

The Ministry of Health Decision No. 4128/2001/QĐ-BYT dated October 3, 2001, promulgates regulations on conditions ensuring food safety at collective canteens, kitchens, and pre-packed meal processing establishments.

• Hygiene conditions for kitchen facilities
  • The location of the kitchen, dining area, or pre-packed meal processing facility must ensure environmental hygiene and be separated from toilets and other sources of contamination.
  • The kitchen must be designed and organized in a one-way flow: area for receiving, storing, and handling fresh food and ingredients – processing area – serving or distributing area. The kitchen must be built with waterproof and easy-to-clean materials.
  • Dining rooms, tables, food preparation tables, and storage areas must be kept clean.
  • Trash bins must have lids, and waste must not scatter or leak. Waste must be collected away from food processing and dining areas and removed daily.
  • Leftover food containers must have tight-fitting lids and must not allow leakage or spillage.
  • Drainage systems in processing areas and kitchens must be unclogged, covered, and not exposed.
  • The facility must have a sufficient supply of clean water for regular activities and for workers to wash hands before and after eating. Wells or tanks must be covered and protected from contamination. Water containers for processing and handwashing must be cleaned regularly.
• Hygiene conditions for staff
  • Persons directly involved in food processing and service must be trained in food safety and hygiene knowledge and understand their responsibilities.
  • Workers must undergo health checks before employment, annual checkups, and stool tests at least once a year. Those with skin diseases or infectious diseases as listed in Decision No. 505/BYT-QĐ dated April 13, 1992, must temporarily stop handling food until fully recovered.
  • Personal items and clothing must not be kept in food preparation areas.
  • All staff must maintain personal hygiene, keep nails short and clean, and wash hands with soap before handling or serving food. Food must be portioned using utensils, not bare hands.
  • Food handlers must not eat, drink, chew gum, or smoke in the kitchen.
• Hygiene conditions for utensils
  • Dishes, bowls, spoons, chopsticks, and other utensils used for dining must be cleaned and dried.
  • Holders for chopsticks and spoons must be clean, dry, and made of waterproof materials. Utensils must only be placed in holders after cleaning and drying.
  • Food baskets must be kept clean and not placed on dirty or damp floors.
  • Knives, cutting boards, pots, and other tools must be cleaned immediately after use and stored hygienically. Food preparation surfaces must be waterproof and easy to clean.
  • Separate knives and cutting boards must be used for raw and cooked foods.
  • Only detergents approved for food preparation may be used; industrial cleaning agents are prohibited.
• Hygiene conditions in food processing and storage
  • Water sources must be tested quarterly (or monthly during digestive disease outbreaks) by the provincial Preventive Medicine Center and disinfected according to health regulations.
  • It is strictly prohibited to use food additives, colorants, or artificial sweeteners not approved by the Ministry of Health.
  • Spoiled, bruised, or diseased animal products must not be used for cooking.
  • Cooked food must be covered to prevent flies, dust, and insects; cloths must not be used directly to cover food.
  • Cooked foods containing meat or seafood must be reheated after two hours if not kept at temperatures below 10°C.
  • Fresh vegetables and fruits must be soaked thoroughly and rinsed at least three times with clean water or washed under running water.

3. Overview of Borax and Formaldehyde in the food processing safety material

• Some regulations on Borax and Formaldehyde
  • Borax and Formaldehyde are prohibited for use in food processing under Decision No. 3742/2001/QĐ-BYT dated August 31, 2001, issued by the Minister of Health.
  • Decision No. 3390/2000/QĐ-BYT promulgates “Standards for qualitative and semi-quantitative determination of Sodium Borate and Boric Acid in food.”
  • Decision No. 3671/QĐ-BYT dated September 27, 2012, approves “Guidelines for infection control,” allowing the use of Formaldehyde only for sterilizing medical instruments.
• Borax
  • Chemical properties: Borax (Sodium Tetraborate, Na₂B₄O₇·10H₂O) is a white crystalline powder, slightly astringent, with a strong odor. It is insoluble in acid, slightly soluble in cold water, more soluble in hot water, and hydrolyzes to form boric acid: Na₂B₄O₇ + 7H₂O → 4H₃BO₃ + 2NaOH.
  • Industrial production: Produced from minerals such as polyborates through reactions like:
    2Ca₂B₆O₁₁ + 4Na₂CO₃ + H₂O → 3Na₂B₄O₇ + 4CaCO₃ + 2NaOH or from Mg₃B₈O₁₅ + 6HCl + 9H₂O = 8H₃BO₃ + 3MgCl₂; 4H₃BO₃ + 2NaOH = Na₂B₄O₇ + 7H₂O
  • Uses: On the market, borax is widely used, for example as an antibacterial agent, in laundry detergents, cleaning agents, corrosion inhibitors, and in the ceramic glaze and heat-resistant glass industries. Occasionally, borax is also used as an antibacterial and food preservative. However, when used in high concentrations, it is highly toxic to human health. When ingested, borax is broken down into boric acid in the digestive tract, causing systemic poisoning.
  • Borax can also cause chronic toxicity (due to accumulation in the body), affecting digestion, absorption, and metabolism, and negatively impacting kidney function, with symptoms such as loss of appetite, weight loss, diarrhea, seizures, and kidney failure.

  • Borax is highly toxic; in children, ingestion of 5–10 grams can cause acute poisoning with symptoms of nausea, vomiting, severe diarrhea, shock, and possibly death. Short-term toxicity testing of borax on white rats and cats has shown growth retardation and liver damage. The oral median lethal dose (LD₅₀) of borax in rats is 5.66 g/kg; the oral LD₅₀ of boric acid in rats is 2.66 g/kg. If ingested, boric acid can cause nausea, vomiting, diarrhea, muscle stiffness and cramps in the abdominal region, erythema of the skin and mucous membranes, cardiovascular collapse, rapid heart rate, hallucinations, convulsions, and coma. Continuous ingestion of boric acid may lead to Borism (characterized by dry skin, rash, and stomach disorders). Ingestion of 5 grams of boric acid by a child or 5–20 grams by an adult can be fatal.

• Formaldehyde
  • Formaldehyde is a highly toxic organic compound, widely used in industry, with the chemical name Formaldehyde.
  • It exists as a colorless gas with a pungent odor and dissolves easily in water to form Formalin.
  • It is flammable and volatile at room temperature, present in car exhaust, smoke, and industrial emissions. It is produced by oxidizing methanol (CH₃OH) with a silver catalyst at 500–600°C.
  • Formaldehyde combines with food proteins, preventing decomposition but making them indigestible. This property is misused to preserve foods like noodles, rice papers, and vermicelli.
  • In medicine, Formaldehyde is used as a disinfectant and preservative for biological specimens and corpses. However, prolonged exposure causes severe health risks.
  • Health impacts:
    • Causes acute irritation of the eyes, nose, and respiratory tract.
    • Leads to coughing, asthma, bronchitis, and even suffocation at concentrations of 1/20,000 in air.
    • Causes dermatitis, allergies, and hives upon skin contact.
    • Ingestion may lead to digestive disorders, stomach ulcers, and colon inflammation.
    • High exposure can cause death and increase the risk of various cancers (nasal, throat, lung, and gastrointestinal).
    • May cause chromosomal abnormalities and fetal developmental issues in pregnant women.

4. Knowledge and practices on food hygiene and safety for food handlers

• Knowledge: Individuals directly involved in food production and processing must have basic knowledge of:
  • Food hygiene and safety hazards.
  • Conditions ensuring food hygiene and safety.
  • Methods of maintaining food hygiene and safety in production, processing, storage, transportation, and consumption.
  • Good hygiene and safety practices.
  • Legal regulations on food hygiene and safety.
  • Good Manufacturing Practice (GMP), Good Hygiene Practice (GHP), and Hazard Analysis and Critical Control Point (HACCP).
• Practice: Individuals directly involved in food processing must comply with the following requirements:
  • Personal hygiene:
    • Wear protective clothing, aprons, masks, and hairnets when processing food.
    • Keep nails short and clean; do not wear jewelry when handling ready-to-eat food.
    • Do not eat, drink, smoke, or chew gum in food production areas.
  • Good food processing practices:
    • Use safe raw materials with clear origins and proper certification. Do not use unapproved food additives or processing aids. Maintain records of food sources and processing documentation.
    • Regularly clean equipment, the production area, and dining areas; properly dispose of waste.
    • Do not allow animals into food processing areas.
  • Good hand hygiene practices:
    • Wash hands after using the toilet, touching raw food, blowing the nose, touching waste, scratching, or touching any part of the body, and after breaks.
    • Wash hands before handling food.
    • Dry hands using disposable paper towels, clean cloth towels, or air dryers; do not wipe hands on clothes or aprons.
    • Wash hands thoroughly with soap and clean water.
    • If there are cuts or wounds on hands, cover them with waterproof bandages and wear gloves when handling food.

---

II. The Situation of Food Hygiene and Safety in the Occupational Safety Document on Food Processing

1. The Situation of Food Hygiene and Safety Worldwide in the Occupational Safety Document on Food Processing

• According to a recent report by the World Health Organization (WHO), more than one-third of the population in developed countries is affected by foodborne diseases each year.
• In developing countries, the situation is much more severe, causing more than 2.2 million deaths annually, most of which are children. The recent crisis (2006) in Europe involved 1,500 farms using hay contaminated with Dioxin, resulting in the residue of this toxin in livestock meat products circulated across several continents. The global spread of meat and bone meal from cattle infected with Bovine Spongiform Encephalopathy (BSE, commonly known as mad cow disease) raised concerns in many countries. According to WHO’s 2006 report, the avian influenza (H5N1) outbreak occurred in 44 countries across Europe, Asia, Africa, and the Middle East, causing significant economic losses. In France, 40 countries refused to import French chicken products, leading to losses of 48 million United States Dollars per month. In Germany, avian influenza caused losses amounting to 140 million Euros. In Italy, 100 million Euros were spent on avian flu prevention, while the United States spent 3.8 billion United States Dollars to combat the disease.
• Food poisoning incidents have been increasing globally. In the United States, there are approximately 76 million cases of foodborne illness each year, with 325,000 hospitalizations and 5,000 deaths. On average, 175 out of every 1,000 people suffer from foodborne illness annually, and the cost per case is 1,531 United States Dollars (US-FDA 2006). Australia, despite having a Food Law since 1908, still records about 4.2 million cases of foodborne illness and foodborne infectious diseases each year. On average, 11,500 acute foodborne cases occur daily, and the cost per case is 1,679 Australian Dollars. In the United Kingdom, 190 out of every 1,000 people suffer from foodborne illness annually, with an average cost per case of 789 British Pounds. In Japan, the 2000 food poisoning incident caused by contaminated low-fat milk containing Staphylococcus aureus resulted in 14,000 victims across six provinces. SNOW BRAND Dairy Company compensated 4,000 victims at a rate of 20,000 Yen per person per day, and the General Director was dismissed. During the 2001 mad cow disease (BSE) outbreak in Europe, Germany spent 1 million United States Dollars, France spent 6 billion French Francs, and the entire European Union spent 1 billion United States Dollars on measures to prevent foot-and-mouth disease in the same year. The European Union countries also spent 500 million United States Dollars on the “culling” and “import ban” measures. In China, on April 7, 2006, a school in Shaanxi Province experienced a food poisoning outbreak affecting more than 500 students. On September 19, 2006, another incident occurred in Shanghai where 336 people were poisoned after consuming pork containing Clenbuterol hormone residues. In Russia, an average of 42,000 deaths occur annually due to alcohol poisoning. In South Korea, in June 2006, 3,000 students from 36 schools suffered from food poisoning.

2. The Situation of Food Hygiene and Safety in Viet Nam in the Occupational Safety Document on Food Processing

• According to statistics from the Ministry of Health, between 2004 and 2009, there were 1,058 food poisoning incidents, averaging 176.3 cases per year, with 5,302 people affected and 298 deaths (49.7 deaths per year). On average, the incidence rate of acute food poisoning was 7.1 people per 100,000 population per year. In 2009 alone, there were 152 cases of food poisoning affecting 5,212 people and resulting in 31 deaths. Compared with 2008, the number of food poisoning cases in 2009 decreased by 53 incidents (25.9%); the number of affected people decreased by 2,616 (33.4%); the number of hospitalizations decreased by 1,888 (31.3%); and the number of deaths decreased by 26 cases (42.6%). Regarding the causes of food poisoning, 29.6% of incidents were due to microbial contamination, 5.2% due to chemical contamination, 24.7% due to naturally toxic foods, and 40.5% were of unidentified causes.
• In 2010 alone (up to December 20, 2010), there were 175 food poisoning incidents nationwide (including 34 incidents involving more than 30 people), affecting 5,664 people and causing 42 deaths. Compared with the average data of 2006–2009, the number of food poisoning incidents decreased by 9.1%, the number of affected people decreased by 17.6%, and the number of deaths decreased by 19.2%.

It is noteworthy that among the 42 deaths, 14 were caused by methanol (industrial alcohol) poisoning, accounting for 33.3%; 23.8% were due to poisonous mushrooms; and 16.7% were due to pufferfish poisoning.

---

III. Legal Documents Related to the Occupational Safety Document on Food Processing

• QCVN 14:2008/BTNMT – Domestic wastewater
• QCVN 26/2016/BYT – Environmental temperature standards at workplaces
• Law on Occupational Safety and Hygiene No. 84/2015 dated May 15, 2015, effective from July 1, 2015
• Circular No. 06/2020/BLĐTBXH – Promulgating the list of occupations and jobs with strict requirements on occupational safety and hygiene
• Decision No. 3733/2002/QĐ–BYT, dated October 10, 2002, issued by the Ministry of Health – Promulgating 21 occupational hygiene standards, 5 principles, and 7 occupational hygiene parameters.
• Law on Fire Prevention and Fighting No. 40/2013/QH13, dated November 22, 2013 – Amending and supplementing a number of articles of the Law on Fire Prevention and Fighting No. 27/2001/QH10.
• Chemical Law No. 06/2007/QH12, dated November 21, 2007 – Regulating chemical activities, safety in chemical operations, rights and obligations of organizations and individuals participating in chemical activities, and state management of chemical activities.
• QCVN 26/2016/BYT – National technical regulation on microclimate – permissible microclimate values at workplaces.
• TCVN 7321 – Thermal environment – determination and calculation…
• According to Circular No. 30/2012/TT-BYT – Regulations on food safety conditions for food service businesses and collective kitchens.
• Circular No. 15/2012/TT-BYT dated September 12, 2012, issued by the Ministry of Health – Regulations on general food safety conditions for food production and business establishments.

---

CHAPTER II: RISKS CAUSING UNSAFETY IN COOKING AND FOOD PROCESSING AT COLLECTIVE KITCHENS

I. Risks Causing Unsafety in Food Processing

1. Splashing in the Occupational Safety Document on Food Processing

• During the cooking and food processing process in collective kitchens, ingredients or food may splash and cause burns to workers.

2. Sharp Objects in the Occupational Safety Document on Food Processing

• Knives, scissors, and sharp utensils used during cooking and food processing in collective kitchens or household kitchens always pose potential safety risks, which may cause skin injuries or damage to functional body parts.

3. Slippery Surfaces in the Occupational Safety Document on Food Processing

• The floor at workplaces or in households becomes slippery and hazardous when splattered with oil, grease, or food. Such incidents may lead to regrettable accidents for workers during cooking and food processing. The likelihood of slipping or not slipping depends on the awareness of the slippery hazard. If the floor or stairs are detected to be slippery, greasy, or wet, extra caution and focus are needed to avoid falling. The ability to regain balance when slipping accidentally may help escape danger, but this ability is limited, especially for the elderly, women, and children.

4. Food Poisoning in Food Processing Safety Documents

• The main causes of food poisoning are consuming contaminated or chemically polluted food (heavy metals, mycotoxins, etc.). Summer food poisoning often occurs due to microbial contamination (bacteria, parasites), as the high temperatures during summer create favorable conditions for microorganisms to multiply and thrive. In particular, animal-based foods such as meat, eggs, fish, and milk are rich in protein, making them an ideal environment for pathogenic microorganisms to develop, turning food into toxic substances.
• Infectious organisms, including various types of bacteria, viruses, parasites, or their toxins and secretions, are the most common causes of food poisoning. The bacteria that contaminate food can exist everywhere in the air, especially when the weather is sunny or during seasonal changes, which accelerate bacterial growth in food.
• Certain types of food are at higher risk of causing food poisoning:
  • Poisoning from eating food contaminated with microorganisms or microbial toxins: Eating raw or undercooked meat, fish, and seafood (clams, mussels, oysters, crabs); eating dishes containing undercooked eggs; consuming salads; drinking unpasteurized fruit juice; or consuming unpasteurized milk and dairy products.
  • Poisoning from spoiled or expired food.
  • Poisoning from naturally toxic foods such as sprouted potatoes, pufferfish, toxic mushrooms, or poisonous toads.
  • Poisoning from food contaminated with chemical toxins, pesticides, or food additives: Consuming unprocessed raw vegetables such as Brussels sprouts or beans.
  • Natural toxins.
  • Other toxic agents originating from food production, storage, and processing stages. Food poisoning may result from preservatives, ripening chemicals, pesticides, or additives.

5. Pulling and Crushing Hazards in Food Processing Safety Documents

• In every restaurant or hotel, multifunctional bone saw machines are indispensable, especially for cutting large chunks of meat or bones that cannot be handled manually. When choosing a bone saw, attention should be paid to its functions, size, and performance to ensure cost-effectiveness and safety during operation. The bone saw is an essential tool in food processing, particularly for cutting large fish or bones that require precision cuts. However, improper use can cause hand entanglement, skin injuries, or other safety incidents.

• The bone saw is widely used in:
  • Frozen meat processing industries, restaurants, hotels, and meat processing facilities: The bone saw helps divide large frozen meat or fish blocks quickly and efficiently.
  • Noodle and soup restaurants: Used daily for cutting large bones (such as marrow bones) to prepare broth.

• Outstanding features of bone saw machines:
  • The entire industrial bone saw is made from smooth and durable aluminum alloy.
  • The wide cutting table provides comfort and safety. Made from high-grade stainless steel, it ensures food hygiene and safety. With high power and load capacity, the machine can operate continuously for longer than most models on the market.
  • Ensures user safety during operation.
  • Blade replacement is simple and quick.
  • Automatic blade tension adjustment maintains blade tightness during use.
  • The machine is easy to operate, safe, highly productive, durable, and meets all user expectations for a professional bone saw.
  • Safe operation and durability guaranteed.

6. Chemical Impacts in Food Processing Safety Documents

• Organophosphates
  • Organophosphates are chemicals found in certain agricultural pesticides. They are harmful to the nervous system, interfere with bodily functions, and are dangerous to human health. They are also considered one of the causes of hyperactivity disorders in children.
  • In agriculture, organophosphates are used to kill pests on crops, so residues may remain in agricultural products. Continuous absorption can lead to accumulation in the human body, causing harm. Therefore, choose agricultural products with clear origins and verified quality.

• Dioxin – Toxic Chemical in Food
  • Food is the primary route of dioxin exposure.
  • Dioxin is one of the most toxic chemicals to humans and the environment. It is a by-product of industrial processes involving chlorine, such as pesticide and paper manufacturing. In Vietnam, environmental dioxin contamination is primarily due to U.S. military activities during the war.
  • Dioxin present in soil, water, or pesticides can contaminate food. Studies show that 90% of human dioxin intake comes from food sources.
  • Dioxin damages cell activity, alters DNA, causes deformities, neurological disorders, cancer, and genetic diseases.

• Camel Coloring Agent
  • This coloring agent is present in many foods and beverages such as soft drinks, confectionery, beer, and sauces.
  • It contains carcinogenic compounds like 2-methylimidazole and 4-methylimidazole. When accumulated in large quantities, these compounds can cause cancer. Although most commercial foods maintain safe 4-MEL levels, it is still advisable to limit consumption of artificially colored foods.

• BHA (Butylated Hydroxyanisole)
  • BHA is an antioxidant commonly used in fat-containing foods such as snacks, potato chips, popcorn, cereals, jams, meats, and sausages to prevent oil spoilage.
  • Small doses are generally safe, but prolonged exposure to large doses can damage the liver and kidneys and may cause cancer.

• Artificial Sweeteners
  • Artificial sweeteners are used to reduce sugar intake, especially for diabetic patients. However, excessive consumption can negatively affect gut microbiota, impair glucose absorption, increase blood sugar levels, and raise risks of diabetes, obesity, brain cell damage, and cancer.

• Arsenic (Asen)
  • Arsenic is a highly toxic inorganic compound found in groundwater and surface water. It can contaminate fish, rice, beer, and wine through polluted water sources.
  • A dose as small as 0.06 grams can cause poisoning and death. Long-term low-level exposure leads to intestinal inflammation, gastritis, hair loss, eye and ear pain, weight loss, and potentially death if untreated.

• Preservatives
  • Preservatives are used to extend the shelf life of cooked or processed food. Common preservatives include sulfites, which enhance flavor but may increase toxicity and cancer risks if chlorine compounds are added for whitening.

• Food Coloring Chemicals
  • There are two main types of food colorants: synthetic and natural. Synthetic dyes are water-soluble, stable, and resistant to time, heat, and light. However, exceeding safe limits can pose serious health risks.
• Freshness Enhancing Chemicals
  • Urea is commonly used to preserve seafood like shrimp and fish by inhibiting bacterial growth. However, excess urea can convert into nitrite and nitrate, leading to digestive disorders and cancer. Some producers also use nitrite to keep fruits and vegetables fresh and green, which is equally hazardous.
• Whitening, Crisping, and Preservation Chemicals
  • These chemicals help improve the appearance and texture of food, making them whiter, crispier, and longer-lasting. Borax is often used in making rice paper, noodles, and spring rolls. Overuse can cause severe allergies or even death. Exposure through the respiratory tract, skin, or eyes may also cause irritation, though milder.
  • Food-grade chemicals are necessary in modern processing, but they must be used within safe limits. Overuse for profit endangers consumer health.

---

II. Safety Risks in Food Cooking Operations

1. Fire and Explosion Hazards in Food Processing Safety Documents

• Industrial kitchens pose high risks, particularly fire and explosion hazards, which can cause catastrophic damage. Therefore, fire prevention is critical—not only for kitchen workers but also during the design phase.
• Accidents commonly occur in industrial kitchens, hotel kitchens, and fast-food chains due to the use of open flames, cooking oils, heat-producing appliances, and flammable materials.
• Fires can rapidly escalate into explosions if not handled properly. Hence, fire prevention and firefighting preparedness are vital for safe industrial kitchen operations.

• Statistics show that most kitchen fires are caused by deep fryers and Western-style cooking stoves due to excessive heat, unsafe equipment, or human negligence. High-temperature appliances like six-burner stoves and ovens pose significant fire risks, while Asian-style gas stoves (woks) can also cause severe incidents.

2. Electrical Hazards in Food Processing Safety Documents

• Depending on voltage and current levels, electrical hazards include electric shock, arc flash, electromagnetic radiation, and fire, which can paralyze the respiratory or cardiovascular systems.
• Common causes of electrical accidents include:
  • Contact with live conductors;
  • Touching metallic parts of appliances with damaged insulation;
  • Arc discharge, step voltage, or static electricity.
• Industrial kitchens contain high-power electrical devices such as induction cookers, refrigerators, dishwashers, ovens, microwave ovens, rice cookers, and blenders. Electrical systems must be designed to support total load capacity with additional allowance for future equipment.
• Avoid operating multiple high-power devices simultaneously to prevent overloading and electrical fires.
• Install electrical devices in safe, dry, and well-ventilated areas, away from gas sources and direct sunlight.
• Use three-pin sockets and plugs. Appliances with metallic casings (ovens, induction cookers, refrigerators, etc.) must use grounded three-pin plugs to prevent electric shock from leakage.
• Equip the system with residual-current circuit breakers (RCCB) to automatically cut power during leakage or short circuits. Regularly check grounding systems every six months to ensure safety.

3. Burn Hazards in Food Processing Safety Documents

• Working with heat pressure equipment (ovens, stoves, pots, cabinets, devices, etc.): operating boilers, drying cabinets, cooking stoves, steam ovens, heating devices, heat exchangers, pressure cookers, steam engines, and incinerators.
• During frying operations, inattention may lead to placing a pan of boiling oil on an uneven stove, causing it to tip over and spill onto the lower legs.
• Many fires occur because of cooking at excessively high temperatures. Keep an eye on your food and turn off the stove if you notice smoke or boiling oil. You should also use a cooking thermometer—it helps prevent burning and ensures food is properly cooked.
• Thermal burns are common accidents during cooking. Fires can occur due to cooking at high heat levels. Always monitor your food and turn off the stove when you see smoke or boiling oil. Pot handles or pan grips positioned too far forward can easily be bumped, spilling hot food and causing burns or fires.
• Always wear neat and fitted clothing. Loose clothing made of flammable materials can easily catch food and fire.
• Exercise caution when cooking:
  • Avoid wind blowing directly into the stove flames. Never spray insecticides while cooking, as these contain flammable compounds.
  • Do not leave the stove unattended while in use. Modern electric or induction cookers have timer functions and automatic shutoff mechanisms in case of overheating or spillage.
  • Keep the stove away from flammable materials such as towels, rags, and paper.
  • A fire extinguisher should always be available in the kitchen.
• Preventing burn accidents in domestic and collective kitchens:
  • Arrange kitchen utensils such as thermos bottles, soup pots, and hot rice containers in safe areas to prevent fire, explosion, or electric shock risks.
  • Properly manage and use household chemicals and detergents following safety regulations and safe distances to minimize burn hazards.

4. Splattering Hazards in Food Processing Safety Documents

• Commonly encountered during frying or grilling when there is no protective covering. Some ways to minimize oil splattering while cooking include:
• Choose the appropriate pan: Select wide pans for frying with a minimum side height of 5 centimeters.
• Be mindful of pan handle placement:
  • Turn the handle inward and ensure the pan sits level and centered on the stove. This prevents accidental contact by the cook or passersby.
• Pay attention to the food being fried:
  • Do not place wet food, such as water-soaked potatoes, into hot oil because water causes oil to splatter. Water and oil do not mix. Likewise, avoid transferring vegetables or roots directly from boiling water into hot oil—allow them to drain and cool completely before frying.

• Use protective screens:
  • Cover the pan with a splatter screen to prevent hot oil from escaping while frying. These screens are available at kitchenware stores.
• Use the benefits of salt:
  • Sprinkle a small amount of salt on the pan surface before frying foods high in fat. Salt helps reduce oil splattering during cooking.

5. Slipping and Falling Hazards in Food Processing Safety Documents

• Cooking processes often cause slippery conditions in kitchen areas when water, oil, or other liquids spill on the floor. Employees and cooks may fall if they lack proper safety skills or appropriate personal protective equipment.

6. Environmental Pollution and Its Impact on Human Health

• Everyday activities such as cooking, cleaning, and opening windows may seem harmless but can contribute to indoor air pollution. In collective kitchens, this pollution is a serious issue since up to 80% of human activities involve food preparation. Many people believe air pollution only occurs outdoors, but indoor environments, especially kitchens, can also pose significant air quality risks.
• Recent studies have examined the relationship between outdoor and indoor air pollution, particularly in collective kitchen environments.
• Researchers measured six outdoor and six indoor points in collective kitchens. Results showed that ultrafine particle concentrations outdoors during peak hours reached 27,000–31,000 particles/cm³, similar to the average fine dust levels recorded in Beijing in 2014 (30,000 particles/cm³).
• The research revealed that indoor dust not only comes from outdoor sources but also from food processing activities, especially cooking. In one measurement, indoor dust concentration exceeded outdoor levels during frying and cooking periods. The United States Environmental Protection Agency (EPA) found that dust and harmful microorganisms accumulate on surfaces, fabrics, and in the air—originating from cooking, smoke, and poor ventilation. Regular dust particles measure about 20 micrometers (μm), fine dust about 10 μm, and ultrafine dust less than 2.5 μm. Ordinary masks cannot block such small particles, which easily enter the body, causing respiratory diseases, cancer, and even altering human DNA.
• The World Health Organization (WHO) reports that 4.3 million people die prematurely each year from indoor air pollution caused by inefficient solid fuel use during cooking. Among these, approximately 12% die from pneumonia, 34% from stroke, 26% from ischemic heart disease, 22% from chronic obstructive pulmonary disease, and 6% from lung cancer.
• Researchers at Texas Tech University and Utah State University heated oil in a pan and observed what happened when water was added. They discovered that evaporating water caused fats to explode into microscopic droplets that dispersed into the air, contributing to indoor pollution. Inhalation of these particles poses health risks.
• According to Professor Jeremy Marston from Texas Tech University, “No matter the type of cooking involving oil and grease, chefs are exposed to the effects of water interacting with hot oil. We found that even a single drop of water releases numerous tiny oil droplets into the air. Foods with high water content, such as chicken and vegetables, are the most hazardous.”
• Professor Marston added, “Millions of people die globally due to indoor air pollution, yet the danger from cooking like this is rarely recognized. Our research aims to guide improved ventilation system designs to remove ultrafine grease particles.”
• Scientists are now using high-speed video technology to record and analyze the size and distribution of oil droplets to understand how they pollute unventilated kitchens.

• Researchers hope their findings will guide the design of improved ventilation systems to remove ultrafine airborne grease particles.
• The findings were presented at the 70th Annual Meeting of the American Physical Society’s Division of Fluid Dynamics in Denver, Colorado.

7. Wastewater in Food Processing Safety Documents

• Kitchen and canteen wastewater primarily contains high levels of grease and oil from cooking and cleaning activities. It also includes organic matter and nutrients such as nitrogen and phosphorus. If discharged untreated, this wastewater can severely affect aquatic environments. Part of the wastewater also originates from employee restrooms in kitchen facilities.

No.	Parameter	Unit	Value	QCVN 14:2008/BTNMT, Column A
1	PH	—	6.8	5 – 9
2	BOD5	mg/l	450	30
3	SS	mg/l	300	50
4	Oil and Grease	mg/l	55	10
5	Nitrate (NO3-)	mg/l	25	5
6	Phosphate (PO4 3-)	mg/l	12	6
7	Total Coliform	mg/l	5000	3000

 

• Process Description
  • Preliminary Treatment
    • Wastewater from canteens and kitchens, after being discharged, passes through a bar screen to remove large-sized waste. After that, the wastewater is directed to an oil separation tank to remove oil generated from the cooking process in the kitchen area. The collected oil is regularly skimmed off and stored in containers, which are periodically collected by an authorized unit. Wastewater from the septic tank and the oil separation tank is gathered into the equalization tank to stabilize the flow rate and concentration before passing through subsequent biological treatment units. At the bottom of the tank, an aeration system is installed to prevent sludge deposition and the generation of unpleasant odors.
  • Biological Treatment
    • The wastewater then flows into the Anoxic tank (oxygen-deficient tank). In the Anoxic tank, NO₃– present in the wastewater is converted into molecular nitrogen (N₂) and released into the atmosphere, thereby reducing nitrate concentration. After that, the wastewater continues to the Aerotank (aerobic biological tank). In the Aerotank, the ammonia in the wastewater is converted into nitrite and nitrate. A portion of the nitrate generated during the aerobic process is recirculated to the Anoxic tank for denitrification, while another portion settles in the activated sludge at the bottom of the biological settling tank. The treated wastewater overflows to the disinfection tank after sedimentation, while sludge accumulates at the bottom of the tank.
  • Sludge Treatment
    • A portion of the sludge from the tank is recirculated to the Aerotank to maintain biomass levels, while another portion is directed to the sludge holding tank. The sludge is then compressed and periodically collected by an authorized unit. The separated water is pumped back to the equalization tank for further treatment.
    • Chlorine is added to the wastewater in the disinfection tank to remove any remaining impurities. The treated wastewater is discharged into the receiving source, meeting the standards of QCVN 14:2008/BTNMT.
  • The kitchen is always the main area for food preparation in households, hotels, and restaurants; therefore, absolute hygiene must always be ensured. However, currently, in some restaurants and hotels, kitchen wastewater treatment is not sufficiently prioritized. Many facilities still directly discharge untreated wastewater into the environment, contributing significantly to current pollution problems.

• Characteristics of Kitchen Wastewater
  • As you may know, kitchen wastewater contains many difficult-to-decompose substances that pose serious risks to the ecological environment. This impacts living organisms in the discharge areas or downstream environments. Without thorough treatment, kitchen wastewater can cause severe harm to the surrounding ecosystem.
  • Due to the diversity of wastewater types, treatment becomes challenging. Without modern treatment technologies, the results will be ineffective. In particular, if outdated wastewater treatment systems are used, the treated water will fail to meet quality standards. Consequently, the problem remains unsolved while costs increase unnecessarily.
  • Environmental sanitation in the kitchen is of utmost importance.
• Overview of Kitchen Wastewater Properties
  • Kitchen wastewater is essentially domestic wastewater generated from human activities in cooking and cleaning areas. Activities such as washing ingredients and dishes contribute to its composition, which is similar to general domestic wastewater.
  • Kitchen wastewater contains a high concentration of organic substances, numerous pathogenic microorganisms, and bacteria that decompose organic matter. These organisms are essential for biodegradation processes but simultaneously generate harmful detergents and chemical residues. If kitchen wastewater is not properly treated, it will become a serious environmental hazard.
  • It is especially important to note that kitchen wastewater flow is unstable, depending on the cooking and cleaning activities within the kitchen. Therefore, treating kitchen wastewater is extremely difficult for any treatment system. However, if not promptly managed, this wastewater will be discharged directly into the environment.
  • This must not be allowed to happen, as it causes extremely negative effects on the ecological and living environment. It also heavily impacts local water bodies. Therefore, it is necessary to apply advanced wastewater treatment technologies.
• MET Technology Kitchen Wastewater Treatment System
  • For kitchen wastewater with unstable flow characteristics, selecting an appropriate treatment system is difficult. For instance, using chemical treatment methods would be costly due to the need for reaction tanks that must be operated multiple times daily.
  • Because leftover food decomposes rapidly, repeated treatment is required throughout the day to avoid unpleasant odors, especially in restaurants and hotels, where bad odors could negatively affect customers and reduce business performance. Hence, high-quality and reliable technology is needed. The MET Technology Kitchen Wastewater Treatment System applies mechanical treatment methods. The MET technology features a closed system that provides superior efficiency in kitchen wastewater treatment.
  • With an automatic filtration mechanism, the unstable flow rate of kitchen wastewater is no longer a problem. Designed and manufactured domestically using local materials, it ensures low investment and installation costs, offering practical advantages for kitchen wastewater treatment in our country today.

---

CHAPTER III: CONTROL AND PREVENTIVE MEASURES

I. System Control Measures in the Food Processing Safety Document

1. Identification of Hazardous and Harmful Factors in Food Processing and Cooking

a) Hazardous Factors

• • These are factors that, when acting on the human body, often cause immediate accidents such as injuries, crushing of body parts, destruction of the human body, or even death.
  • Transmission mechanisms of machinery, equipment, kitchen tools, meat grinders, bone saws, and other food processing or cooking devices.
  • Gears; Belts, Chains; Moving machinery;
  • Conveyor belts; Rolling, pressing, stamping machines; Crushing or grinding machines; and others.
• Causes of Occupational Accidents
  • Loss of balance during operation;
  • Failure to use specialized tools or personal protective equipment;
  • Lack of guarding for hazardous areas; Inadequate safety supervision.
• Corrective Measures
  • Ensure that newly purchased equipment has proper guards and safety covers;
  • Install barriers or shields to prevent direct contact with dangerous components;
  • Provide workers with safety work instructions and appropriate protective equipment.
• Preventive Measures
  • Cover all transmission components;
  • Isolate hazardous zones.
  • Electrical Source
    • During food processing and cooking, electrical accidents may occur due to equipment, tools, and sockets in the kitchen area.
    • Depending on voltage and current intensity, electrical hazards may include: Electric shock, Electrical discharge, Electromagnetic fields, Fire—potentially causing paralysis of the respiratory and cardiovascular systems.
  • Common Electrical Accident Scenarios:
    • Contact with conductive materials carrying electric voltage;
    • Touching metallic parts of electrical devices when insulation is damaged;
    • Electrical arc exposure;
    • Step voltage incidents;
    • Static electricity discharge.
• Corrective Measures
  • Insulation: ensure proper insulation of equipment and wires; maintain safe distances for high-voltage systems;
  • Grounding protection: to reduce voltage levels;
  • Neutral grounding protection: for single-phase short circuits;
  • Protective circuit breakers: disconnect electrical equipment from the grid during faults;
  • Use isolation transformers to lower voltage levels;
  • Potential equalization: isolate and limit current through the human body.
• Electrical Safety Preventive Measures
  • Safe operation: workers must be professionally trained in electrical work, receive electrical safety training, and be physically fit. Work must follow diagrams, safety procedures, and operation permits;
  • Provide timely and proper first aid for electric shock victims;
  • Prevent static electricity;
  • Provide adequate protective tools, personal protective equipment, safety barriers, and warning signs.
• Heat Source
  • Thermal pollution is a type of pollution that must be considered during food cooking and processing. Heat mainly originates from cooking areas, particularly from collective kitchens handling large food quantities.
  • Some harmful effects of heat sources
    • Excessive heat weakens health;
    • Can cause occupational accidents, heat stroke, burns, or even fires and explosions.
  • Preventive Measures
    • Use standard-compliant tools and equipment;
    • Operate following proper procedures and safety methods;
    • Ensure that workers are professionally trained, and receive occupational safety and fire prevention training;
    • Provide adequate fire extinguishing devices and personal protective equipment;
    • Ensure readiness for firefighting conditions.
• Splashes
  • Food, ingredients, or cooking oil splashing onto workers can cause burns, skin injuries, or even blindness if it reaches the eyes. Food processing facilities and collective kitchens must ensure safety measures such as using lids and protective meshes, maintaining safe distances, and providing personal protective equipment such as masks, gloves, and aprons.
• Sharp Objects
  • Knives, scissors, cutting blades, machinery, kitchen tools, and other sharp equipment can injure the skin, fingers, or other body parts of workers. Machines and equipment with sharp parts must be guarded or isolated. Employers must provide safety training and equip workers with appropriate personal protective equipment. Technical measures should be prioritized to minimize direct contact with sharp objects.
• Falling or Collapse
  • Restrict unauthorized personnel and vehicles from entering hazardous areas; use safe lifting and lowering devices when moving goods, materials, or equipment during food processing and cooking; avoid storing materials near floor edges or high platforms; install floors, railings, and safety nets when working at heights; provide solid support when working under potentially collapsing areas.
• Fire and Explosion
  • Boiler explosion risks may arise due to low water levels or overfilling;
  • Molten metal from electric arcs can ignite flammable materials or heat combustible chemicals, leading to further fire and explosion risks;
  • Electrical sparks are a common heat source in industrial production, with temperatures exceeding ignition points of fuels, thus easily causing fires and explosions;
  • Heat and radiation from furnaces or hot surfaces can ignite nearby chemicals or flammable vapors, leading to fires and explosions;
  • Heat from direct or indirect sunlight intensified by metal roofing, plastic, or glass materials can also cause similar effects, resulting in fires or explosions;
  • Food processing and cooking operations typically involve large quantities of fuel (oil, coal, gas, etc.). Therefore, preventive measures such as lightning protection, short-circuit prevention, and particularly fire and explosion prevention are necessary. If such incidents occur, they can cause severe economic, social, and environmental damage, affecting water, soil, and air ecosystems.
  • Moreover, they endanger human and animal lives and property in the affected area.
  • Fire and explosion prevention: Since most materials used in factories are flammable, especially during the dry season, workers must wear protective clothing and necessary labor safety equipment during working hours.

b) Harmful Factors

• These are unfavorable elements of working conditions that exceed the permissible limits of occupational hygiene standards, reducing workers’ health and causing occupational diseases, such as microclimate, noise, vibration, radiation, lighting, dust, toxic substances, vapors, gases, and harmful microorganisms.
• Harmful factors in production are elements that cause diseases to workers.
• Occupational harmful factors are those that exist in the production process or workplace and adversely affect workers’ health and working capacity.
• Chemicals
  • Chemicals used for food preservation, heavy metals accumulated in food, and similar elements negatively impact human health and can lead to food poisoning and intoxication risks.
  • Chemicals are increasingly used in industrial, agricultural, and construction production, accumulating in soil and water such as Arsenic, Chromium, Benzene, alcohol, dust gases, acid, base, alkali, salt solutions, and non-degradable waste materials. Toxic chemicals can exist in solid, liquid, gas, or dust form, depending on temperature and pressure conditions.
  • Toxic chemicals can affect workers in the form of acute or chronic poisoning. Toxic chemicals are usually classified into the following groups:
    • Group 1: Substances causing burns and skin irritation, such as concentrated acids and alkalis.
    • Group 2: Substances irritating the respiratory system, such as Chlorine, Ammonia, Sulfur Trioxide (SO₃).
    • Group 3: Asphyxiant substances such as Carbon Oxides (CO₂, CO), Methane (CH₄).
    • Group 4: Substances affecting the central nervous system, such as Hydrogen Sulfide (H₂S) with a rotten egg smell, gasoline, etc.
    • Group 5: Substances toxic to body systems such as hydrocarbons (toxic to multiple organs), Benzene, Phenol, Lead, Arsenic, etc.
  • When exposed to toxic chemicals, workers can be poisoned through ingestion, inhalation, or skin contact. Among these, inhalation is the most dangerous, accounting for 95% of poisoning cases. The toxins enter the body and may participate in biochemical processes, transforming into non-toxic substances, or sometimes into more toxic ones. Some toxins accumulate in the body, while others are expelled through the skin, breath, urine, sweat, or milk, depending on each chemical’s nature.
• Microclimate
  • The microclimate is the physical state of the air in a confined workspace, including temperature, humidity, radiant heat, and air movement speed. These factors must remain within specific limits suitable for human physiology.
  • Temperatures above or below permissible standards weaken the body, cause muscle paralysis, and increase accident risks when using machinery and equipment. Excessive heat causes neurological, cardiovascular, skin diseases, heatstroke, sunstroke, and occupational cataracts. Excessive cold causes respiratory diseases, rheumatism, mucosal dryness, and colds.
  • High humidity can increase the electrical conductivity of insulation materials, the risk of explosions caused by dust and gases, and hinder the body’s ability to perspire.
  • Wind speed and radiant heat factors that exceed hygiene standards affect health, cause diseases, and reduce human work capacity.
  • Some measures to prevent heat and humidity and ensure appropriate microclimate conditions at work include:
    • Workshops must have natural ventilation, fully utilizing prevailing winds and rational factory layout.
    • Regularly inspect and maintain steam and hot air pipeline systems for leaks.
    • Strictly follow operational procedures, accurately measure raw materials and fuels to ensure high process stability, minimize waste, and facilitate waste management and treatment.
• Microorganisms
  • Workers exposed to pathogenic microorganisms, bacteria, viruses, parasites, insects, and molds during food preparation and cooking in collective kitchens are at risk of occupational diseases.
• Vibration and Noise
  • Vibration and noise in food processing and cooking areas depend on the machinery used for meat grinding, bone sawing, and kitchen equipment, affecting workers’ health.
• Ergonomics
  • All work activities must be comfortable, safe, and ensure workers’ health. If work activities are uncomfortable, constrained, or stressful, they can affect health and increase the risk of occupational accidents.
  • Standing posture, lifting, food handling, and cooking operations must ensure safety, avoid collisions, and prevent breakage in kitchen areas.
  • Accident Prevention: Design a comfortable and rational work environment with safety components. Work tools should fit workers’ anthropometrics, and machinery use must be simple and not overly cumbersome, ensuring a balance between work requirements, technology, and human capability to avoid accidents and equipment damage due to human error.
  • Fatigue Prevention: Design workspaces according to workers’ vision range, and establish reasonable work-rest regimes to avoid psychological and visual fatigue.
  • Musculoskeletal Injury Prevention: Determine the forces acting on muscles, bones, and joints, particularly in the lumbar area, and design lifting tasks to prevent strain or injury. Eliminate or reduce unfavorable postures that may cause cumulative trauma. Avoid repetitive manual tasks within one shift to reduce cumulative injuries such as tendonitis, epicondylitis, tenosynovitis, and carpal tunnel syndrome.
• Dust
  • In case of malfunction, these systems emit large amounts of air pollutants such as dust, Carbon Monoxide (CO), Sulfur Dioxide (SO₂), and Nitrogen Oxides (NOx), which impact ecosystems and human health.
  • Food processing includes numerous operations such as grain handling, baking, roasting coffee, canning, meat and poultry processing, cooking, and ready-to-eat meat production. Airborne contamination characteristics should be evaluated to design proper dust or vapor control systems.
• Bioaerosols
  • Airborne microorganisms or bioaerosols—solid or liquid micro-particles—may carry bacteria and sometimes cause dangerous diseases that affect environmental quality and safety during food processing. These include bacteria, yeasts, molds, viruses, and pollen.
  • Transmission Mechanism: They may develop in hidden areas such as forklifts moving across wet floors or containers where condensation accumulates in HVAC systems. Microorganisms can remain airborne and spread through airflow, vehicle movement, pressure variations, and temperature gradients. However, under controlled ventilation conditions, bioaerosols are unlikely to spread widely, emphasizing the importance of maintaining proper air pressure and filtration levels exceeding Good Manufacturing Practices (GMP).
• Types of Air Pollution in Food Processing:
  • Dust generated during dry material handling.
  • Dry dust ranges from fine to coarse particles. Microorganisms may attach to these particles during product transfer at packaging or discharge points.
  • Transmission Mechanism: Particle size, process type, speed, and material properties affect dust characteristics and dispersal, often exceeding the local area. Their behavior depends on particle surface properties, traffic movement, and airflow. They may absorb moisture (hygroscopic) or, worse, be flammable or self-igniting, leading to explosions.
• Wet Emissions such as Fats or Smoke
  • Emissions from hot oil, grease, and vapor during deep frying in industrial kitchens or smoke from burning solid fuels require proper ventilation and fire suppression systems.
• Hazards
  • Vegetable oils and animal fats produce fine particles smaller than 1 μm, posing a Class K fire hazard. Ventilation and fire suppression systems must comply with NFPA 96 standards.
• Risk Assessment and Control
  • Dust and vapor control design in food processing begins with careful assessment of processes and contaminants present. Ducted vacuum systems are suitable for dry dust, while vapor collectors work best for wet exhaust from cooking chimneys.
  • Additional tools enhance system safety and reliability.
  • Measures to control air contaminant spread during food processing may require supplemental tools such as cyclone pre-filters, stainless steel designs, non-slip ducts, stainless steel surfaces, and FDA-compliant coatings. When handling combustible dust, use flame-retardant chemical filters and sprinkler-equipped collection chambers.
  • Lighting
    • Workshops and food preparation areas must be adequately lit for clear observation and processing.
    • Insufficient lighting increases defects, reduces productivity, and raises the risk of occupational accidents.
    • Proper lighting protects vision, reduces fatigue, prevents occupational accidents and diseases, and increases productivity.

2. Supervision of Food Processing Operations

a) Cleaning, Collection, and Disposal

• Food processing and cooking in collective kitchens generate dust accumulating on machinery, equipment, and walls; therefore, clean using vacuum devices, wash work areas thoroughly, and collect and manage waste (including hazardous waste) according to legal and company regulations.
• General principles for waste disposal:
  • Do not discard waste (containers, used packaging with hazardous residues, etc.) indiscriminately; all waste must be stored in approved, labeled hazardous waste containers.
  • Ensure that chemical disposal does not pose risks to humans or the environment.
  • Waste storage areas must comply with current legal safety regulations.
  • It is recommended to contract licensed waste treatment companies or individuals for hazardous waste disposal.

b) Exposure Monitoring

• Workplace environmental monitoring must be conducted regularly or periodically as required. Implement corrective actions to improve working environments, particularly in areas with hazardous chemicals.

c) Medical Surveillance

• Periodic health checks help detect early symptoms of occupational diseases and assess the effectiveness of existing chemical control measures.
• Do not assign individuals with chronic infectious diseases or allergic conditions to work in hazardous chemical areas.

d) Record Keeping

• All health and environmental records must be properly stored and maintained according to regulations.

e) Training and Education

• Food handlers and cooks in collective kitchens must receive adequate training and safety education to competently perform their assigned tasks. Essential training topics include:
• Understanding laws and regulations related to food processing and safety to prevent poisoning.
• Understanding and following food preparation procedures.
• Knowing how to use personal protective equipment and safety devices appropriately, selecting suitable protective equipment that meets quality standards.
• Maintaining personal hygiene, food safety, and learning safe methods for decontamination, washing, and changing protective clothing.
• Keeping and managing records and documents according to regulations.

---

II. PREVENTIVE MEASURES

1. Shielding or Isolating Dust, Waste, and Hazardous Chemical Sources

• Define safe distances or partitions between workers and food processing or cooking areas in collective kitchens to prevent exposure to health or life-threatening risks.
• Machinery and dust-generating sources may be fully enclosed, or the entire production process enclosed, to limit the spread of toxic vapors or gases into the working environment.

2. Ventilation in Food Processing Safety Guidelines

• When cooking areas use gas, oil, or generate dust, proper ventilation is one of the most effective control measures after substitution or enclosure. Suitable ventilation systems prevent harmful substances from escaping into the workplace and channel them through treatment systems before release.
• Common ventilation methods include:
  • Local Exhaust Ventilation: Delivers clean, cool air directly to specific workstations where heat and harmful gases are concentrated.
  • General Ventilation: Dilutes contaminated air by introducing fresh air from outside and removing polluted air from inside. This may be done mechanically (forced ventilation) using pumps or fans, or naturally through open windows, doors, and factory design to enable natural airflow. Forced ventilation offers better control of chemical, dust, and hazardous waste concentrations.
• General ventilation should only be applied in cases involving low-toxicity, non-corrosive substances in small quantities.
• A combination of both local and general ventilation is often most effective.

3. Personal Protective Equipment in Food Processing Safety

a) Respiratory Protective Equipment

• Medical Masks:
  • Workers in collective kitchens should wear respiratory protection during food preparation. When cooking emits toxic substances, gas-filtering respirators should also be used.
• Gas Mask with Filter Cartridge:
  • This type includes a filter cartridge made of tightly packed cardboard sheets that trap dust and vapor, combined with an absorption layer using activated charcoal granules impregnated with chemicals to capture specific toxic gases.
  • Use only when oxygen concentration is above 16% and toxic gas concentration does not exceed cartridge limits (usually below 2%). This mask is convenient but has limited usage time and range.
• Air Supply Respirator:
  • This type uses a rubber hose to draw clean air from outside, either passively or via a pump. It can be used in areas with varying toxicity levels but restricts mobility.
• Oxygen Cylinder Respirator:
  • Exhaled air passes through one-way valves into a backpack device where Carbon Dioxide (CO₂) is absorbed chemically, and oxygen from a cylinder is mixed to form breathable air.
  • This type is heavy, bulky, poses fire risks, and reduces sound perception during use.

b) Eye Protection

• Safety goggles are essential in production workshops and chemical laboratories, particularly when handling acids, alkalis, or generating dust and flying particles.
• Contact lenses must not be worn in dye preparation areas where chemicals may splash into the eyes.

c) Skin Protection

• Protective Clothing
  • Heat-resistant protective clothing should be made from suitable, light-colored materials capable of withstanding hot surfaces, ensuring durability, flexibility, and comfort.
  • Protective clothing must be mechanically durable and not overly stiff. Dark colors should be avoided since they absorb heat and increase discomfort. These garments provide limited-time protection (typically a few hours).
• Gloves
  • Each glove type offers protection against specific solvents. After prolonged use, gloves lose effectiveness, allowing solvents to permeate.
  • Heat-resistant gloves protect against hot surfaces.

4. Improving the Working Environment in the Food Processing Safety Document

• Regularly inspect air quality in production areas, paying attention to toxic gases such as CO, NOx, SO₂, H₂S, HCl, and dust, as well as specific toxic substances for each production zone such as solvent vapors, acid fumes, alkali, chlorine, etc.
• Periodically check and analyze the quality of wastewater and supplied water at the facility, especially drinking and domestic water.
• Organize tree planting and improve infrastructure conditions such as electrical networks, walkways, and drainage systems.
• Arrange workplaces to ensure clear visibility of information, control mechanisms, and signs (warning signs, control buttons, and notes in clear Vietnamese to avoid confusion that could lead to occupational accidents).
• Maintain workplace hygiene.
• Cleaning the workplace helps reduce environmental pollution directly at the worksite, typically performed at the end of the shift before stopping work. Depending on the specific characteristics of each area, cleaning objectives may vary to eliminate particular pollutants, for example:
• Prevent dampness: Ensure proper floor slopes for surface drainage, adequate drainage pipes, and prevent water or liquid spillage and leakage.
• Prevent dust: Perform regular dust extraction.
• Prevent slipperiness and contamination: Wash floors and equipment regularly.
• Prevent bacterial contamination: After normal cleaning, disinfect and sterilize workplaces, kitchen areas, etc.

---

CHAPTER IV: SAFETY TECHNIQUES IN COOKING AND FOOD PROCESSING IN COLLECTIVE KITCHENS

I. Safe Use of Gas in the Food Processing Safety Document

1. Installation of Household Gas Cylinders in the Food Processing Safety Document

• Gas cylinders must not show signs of swelling, corrosion, rusting, or base damage. The information on the cylinder must be clear, within the valid usage period, and consistent with the gas refilling manufacturer’s details. Cylinders must be installed upright, placed in shaded, well-ventilated, and visible locations, at least 1.5 meters away from heat sources or ignition points.
• Do not place gas cylinders in enclosed spaces or near manholes or drains.
• Place gas cylinders away from open flames (such as coal stoves, wood stoves, electric stoves, circuit breakers, switches, etc.).
• Avoid placing cylinders under direct sunlight or near heat sources. Avoid humid or chemically corrosive areas.
• After selecting a proper position, check the valve and ensure it is in the closed position.
• For Kosan “Click-On” regulators, pull the plastic ring downwards, press the regulator onto the cylinder, then push the plastic ring down. Check installation by rotating and pressing gently to ensure it is secure and tight.
• Connect the gas hose to the regulator and secure it using proper hose clamps (do not use metal wire). Ensure the hose is neatly arranged and kept away from heat sources.
• For HP high-pressure regulators: the connection is similar to “Click-On” type. For standard regulators with threaded valves (12 kg or 48 kg cylinders), tighten counterclockwise and check for leaks using soapy water after installation. Follow the same hose connection steps as above.

2. Installation of Gas Stoves in the Food Processing Safety Document

• Place gas stoves in cool, ventilated areas but away from direct drafts (such as windows or doors) and avoid humid or corrosive environments. The stove must be at least 15 cm from the wall and 1.5 meters from overhead objects.
• All hose joints connected to the stove and pressure regulator must be clamped securely. Threaded connections must match properly.
• After installation, check all connections for leaks using soapy water or foam solution. Never use open flames to check for leaks.
• Light the stove to test the flame and adjust the regulator if necessary. Turn off the stove and ensure the cylinder valve is tightly closed.

3. Installation of Gas Water Heaters in the Food Processing Safety Document

• Location: Gas water heaters should be installed in bathrooms, mounted on the wall above the user (height depends on the user’s needs).
• The bathroom must have ventilation openings or an exhaust fan at least 1 meter away from the heater (usually positioned opposite it).
• The gas hose must be fixed along the wall with brackets or hooks to prevent accidental detachment or breakage.

4. Safe Use of Household Gas Stoves in the Food Processing Safety Document

• When lighting the stove: open the cylinder valve first, then the stove valve.
• When turning off: close the cylinder valve first, let the remaining gas burn out, then close the stove valve.
• If the flame goes out unexpectedly, immediately close the cylinder valve, open all windows and doors to ventilate, and remove all sources of ignition.
• Do not relight the stove or operate any electrical devices until the gas smell has completely dissipated to avoid explosions.
• Some notes for safe use:
  • Avoid having the flame extinguished by wind, fans, or spilled water.
  • Use pots proportional to the stove size; avoid large pots on small stoves (risk of tipping) or small pots on large burners (risk of spillage).
  • Children must never be allowed to play with or use the stove.
  • If the stove does not ignite, turn it off immediately; prolonged gas leakage can cause fire or explosion.
• If gas leakage is detected:
  • Immediately recognize the fire and explosion hazard and close the cylinder valve.
  • Strictly prohibit all ignition activities. Ventilate the area and isolate the gas leak zone.
  • Locate the leak using soapy water or foam solution.

5. Safety Regulations for Mini Gas Cylinders in the Food Processing Safety Document

• Mini gas cylinders are small canisters containing approximately 200–250 grams of gas used for portable gas stoves.
• Two types of mini gas cylinders are commonly used:
  • Thin metal-sheet type: contains 95% Butane and 5% Propane, known as butane cylinders. Under normal conditions, the internal pressure is about 3.2 kg/cm² (design pressure < 5 kg/cm²).
  • This type is disposable and must not be refilled.
  • Thicker stainless steel type: can withstand up to 32 kg/cm² pressure and can be refilled multiple times like larger gas cylinders (12 kg or 48 kg types).
• Usage precautions:
  • Check the mini gas cylinder:
    • Before use, ensure the cylinder is new, not rusted, deformed, or swollen. Verify gas type compatibility.
    • Check for leaks at the valve.
    • Do not use old, rusted, deformed, or unverified cylinders or those filled with the wrong gas pressure type.
  • Check the mini gas stove:
    • Before use, ensure proper ignition function and air adjustment mechanism.
    • Clean the burner nozzle.
    • Check the gas connection mechanism.
  • During use:
    • After inserting the cylinder, check for leaks and ignition stability.
    • If leakage occurs, stop using immediately.
    • Place the stove away from drafts. Avoid using oversized pots that cause flames to spread and overheat the gas cylinder, which may lead to an explosion.

6. Firefighting and Gas Leak Incident Handling in the Food Processing Safety Document

• In case of gas leakage:
  • Regularly inspect for leaks. When a gas smell is detected, immediately extinguish nearby flames, turn off the stove, and avoid operating electrical switches.
  • Open doors and windows for ventilation to disperse and dilute gas vapors.
  • Locate the leak using soapy water—never use open flames.
  • Seal leaks by closing valves, applying soap paste, or using adhesive tape or rubber strips to minimize leakage.
  • If unresolved, move the leaking cylinder to an open, ventilated area away from drains, flames, and populated zones. Use inert gases like CO₂ or N₂ to reduce vapor concentration.
  • Mark the area as “No Fire” and notify suppliers or local fire authorities for assistance.
• In case of fire:
  • Immediately close the stove or cylinder valve to cut off gas supply.
  • Move the gas cylinder to a safe location if possible.
  • Trigger a fire alarm, call the nearest firefighting team, and use extinguishers to control the flames.
  • Upon arrival, inform firefighters of the fire location, cylinder positions, and other flammable materials.
  • If the cylinder cannot be moved, continuously spray water on it to cool down. If the fire is extinguished but gas still leaks, handle as in the gas leakage procedure above.

---

II. Exposure to Hot Surfaces and Hot Materials

1. Overview of Heat and Related Factors in Food Processing Safety Documents

During production, workers performing tasks in hot environments or in contact with hot materials or surfaces (from equipment, machinery, tools, or substances) are affected by heat factors, especially thermal heat (heat emitted from equipment, machinery, materials, or tools that makes their surfaces hotter or warmer than the surrounding air under normal conditions). Therefore, understanding the concepts related to heat, the tasks, equipment, and materials involving high temperature, as well as their impacts on workers’ health, is essential.

Some images illustrating burn accidents caused by heat are shown below:

a) Some basic concepts related to heat:

• Heat is the transfer of energy that occurs naturally from a hotter object to another cooler one.
• Heat generation: In general, heat is generated by friction, when two objects rub against each other. (For example: a wheel moving and rubbing against the road surface, two hands rubbing together, or two gears rotating in an engine). However, heat may also be generated in the following cases:
  • Heat generated by electric current: loose electrical wire connections, electric arcs, or sparks;
  • Heat generated by static electricity: occurs when two different surfaces come close together and then separate, or when transferring flammable liquids from one container to another;
  • Heat generated during the mixing of chemicals;
  • Heat generated by thermal radiation: heat from furnaces, stoves, molten steel, etc.;
  • Heat transfer: Heat transfers through materials in three states—solid, liquid, and gas. In any system, heat always moves from an object with a higher temperature to one with a lower temperature and stops when thermal equilibrium is reached. In reality, even in thermal equilibrium (equal temperatures), heat exchange continues, but because the absorbed and released heat are equal, a dynamic balance is maintained.
  • Thermal radiation is the transfer of heat through electromagnetic waves.
    • Thermal radiation can travel through all forms of matter as well as through vacuum. All objects with temperatures higher than absolute zero (0 Kelvin) emit thermal radiation.
    • In thermal radiation, heat flow occurs both from hot to cold and vice versa. However, since the heat flow from hot to cold is always greater than the reverse, the total heat flow is always directed from hot to cold.
    • In practice, a system can involve multiple forms of heat exchange. For example: in solids, the main form is conduction, but radiation can also occur; in liquids and gases, convection also takes place. The heat flow depends on the object’s shape. Thermal radiation can occur between contact surfaces but mainly occurs in a vacuum. Gases can also transmit thermal radiation.
• Heat and volume change of materials: When an object absorbs heat (thermal energy), its volume may change (contract or expand).
  • Example: In summer (hot weather), electrical wires tend to sag, while in winter (cold weather), they become tauter.
• Heat and changes in the state of matter: When an object absorbs heat, it may change its state (from solid to liquid to gas).
  • Example: Under normal atmospheric pressure (1 atm), water begins to freeze into ice at 0°C, exists as a liquid between 0°C and 100°C, and starts to evaporate at 100°C.
• Heat and the sensation of hot/cold: For humans, high temperatures create a sensation of heat, while low temperatures create a sensation of cold.
• Heat and combustion-explosion: Heat is the second element in the fire triangle, which causes combustion or explosion when combined simultaneously with the other two factors in appropriate proportions (except in special cases):
  • Combustion = Fuel + Heat + Oxygen
  • Temperature (symbol: T) is a physical property of matter, defined as a measure of “hotness” or “coldness.” Matter with a higher temperature feels hotter, and vice versa.
  • Melting point of a solid substance – symbolized as Tm (also called the melting/liquefaction point) is the temperature at which a solid begins to change into a liquid state.
  • Boiling point of a liquid – symbolized as T_b (also called the boiling/evaporation point) is the temperature at which a liquid begins to change into a gaseous state.
• The metal with the highest melting point is tungsten, whose valuable property has been applied in making light bulb filaments (since 1910) and producing tungsten steel alloys used for high-speed cutting tools.
• Under normal atmospheric pressure (1 atm), the melting and boiling points of several naturally occurring substances are shown in the table below:

Substance	Water	Cesium (Cs)	Rubidium (Rb)	Potassium (K)	Sodium (Na)	Lithium (Li)	Zinc (Zn)
T0 nc	0	28	38	64	98	180	419
T0 s	100	670	696	762	880	1336	907
Substance	…	Aluminum (Al)	Silver (Ag)	Gold (Au)	Copper (Cu)	Iron (Fe)	Tungsten (W)
T0 m	…	660	962	1,064	1,085	1,538	3,422
T0 b	…	2,519	2,162	2,856	2,562	2,862	5,555

 

• • Temperature measurement unit is degree (symbol: ο). There are three standard systems used for temperature measurement and comparison:
  • Celsius degree (symbol: °C, read as degree Celsius or centigrade degree);
  • Fahrenheit degree (symbol: °F, read as degree Fahrenheit);
  • Kelvin degree (symbol: K, read as degree Kelvin).

• Thermometer is an instrument used to measure temperature, such as mercury thermometers and alcohol thermometers.

– Heat capacity (symbol: C) is the amount of heat required (∆Q) to change the temperature of an object by 1 degree.

C = ∆Q / ∆T

 

Specific heat capacity (symbol: Cm) is the amount of heat required (∆Q) to change the temperature of 1 unit mass (m) of a substance by 1 degree.

C = ∆Q / (∆T × m)

b) Hot materials

• Hot materials are understood as materials that have absorbed heat and stored thermal energy within, emitting radiant heat from their surface to the surrounding environment, causing a hot sensation when touched. For example:
  • Boilers, cooking furnaces, steamers, steel furnaces, clinker kilns, etc., in operation;
  • Metal roofing under sunlight, cooking stoves/pans during food processing;
  • Machines/equipment in operation (without an efficient cooling system);
• Hot surfaces are understood as the outer surfaces of hot materials. For example:
  • Outer casing of boilers, steel furnaces, clinker kilns, etc., in operation;
  • Metal roofing surface under direct sunlight;
  • Outer casing of machines/equipment in operation (without an efficient cooling system);

2. Working environment temperature and occupational health

• Workplace environmental temperature standard: QCVN 26/2016/BYT
• Requirements for microclimate conditions at workplaces by labor category are specified in the following table:

Type of labor	Air temperature range (°C)	Air humidity (%)	Air movement speed (m/s)	Thermal radiation intensity per exposed surface area (W/m²)
Light	20 to 34	40 to 80	0.1 to 1.5	35 when more than 50% of body surface is exposed. 70 when 25% to 50% of body surface is exposed. 100 when less than 25% of body surface is exposed.
Moderate	18 to 32	40 to 80	0.2 to 1.5
Heavy	16 to 30	40 to 80	0.3 to 1.5

 

• For hot and humid working conditions, the air movement speed at the workplace may be increased up to 2 m/s.
• For workplaces with air conditioning systems, the air movement speed may be below 0.1 m/s for light work, below 0.2 m/s for moderate work, and below 0.3 m/s for heavy work, provided that indoor ventilation maintains the concentration of carbon dioxide (CO₂) within permissible limits.
• The temperature difference by height at the working position should not exceed 3°C.
• The horizontal temperature difference in the working zone should not exceed 4°C for light work, 5°C for moderate work, and 6°C for heavy work. The temperature difference between the indoor workspace and the outdoor environment should not exceed 5°C.
• Requirements for microclimate conditions according to wet-bulb globe temperature (WBGT) are specified in Table 2.

Exposure duration to heat sources	Type of labor
	Light	Moderate	Heavy
Continuous	30,0	26,7	25,0
75%	30,6	28,0	25,9
50%	31,4	29,4	27,9
25%	32,2	31,4	30,0

 

• Other calculation methods and levels of impact are applied in accordance with TCVN 7321:2009.
• Impact of workplace temperature on occupational health:
• Heat hazards can cause occupational health problems in hot working environments, manifested through the following signs or symptoms:
  • Cause discomfort and irritation due to dehydration and imbalance of electrolytes in the body (for example: loss of calcium, sodium, potassium ions, vitamins C, B, PP, etc.);
  • Cause heart stimulation, increase heart rate;
  • Affect the functioning of the central nervous system;
  • Reduce concentration, attention, coordination ability, and slow down stimulation and reaction speed;
  • Cause body disorders such as heat exhaustion and convulsions with symptoms of thermal imbalance: dizziness, headache, chest pain, nausea, rapid rise in body temperature, fast breathing, fatigue, etc.
• Skin burn injuries caused by contact with hot materials, surfaces, and high temperatures: Burns (also known as scalds) are injuries caused by heat, chemicals, electricity, or radiation. Most burn cases are limited to the skin, but some may reach deeper layers such as muscles, tendons, joints, and internal organs. – Skin burn accidents occur when in contact with hot materials, surfaces, and high temperatures.

---

III. Food Processing and Preservation Procedures

• Specific Process
  • Step 1. Receiving and inspecting goods
    • All received goods must be thoroughly checked for quantity, quality, and origin. All suppliers must have food safety and hygiene certification. Goods should be inspected by observing color, odor, and external characteristics. All food products must meet the following requirements:
      • For fresh foods: must be fresh, not spoiled;
      • For vegetables, tubers, and fruits: must be fresh, not wilted or yellowed;
      • For spices and dried goods: must have clear origin, still within the expiration date, and not moldy;
      • For frozen foods: must be kept cold upon delivery and within the expiration date;
      • For canned foods: packaging must be intact, not dented, and still within the expiration date.
    • Qualified food must be immediately moved to the processing and storage area. A report must be made, and non-compliant goods must be returned to the supplier.
  • Step 2. Preliminary food processing
    • After inspection, goods and food are classified, pre-processed, and stored according to the following procedures:
      • For food items: washed, pre-processed, and stored in specialized cabinets at appropriate temperatures;
      • For vegetables, tubers, and fruits: peeled, trimmed, washed, and soaked in diluted saline solution or disinfected with specialized equipment to ensure safety. If not processed immediately, store in plastic bags for preservation;
      • For spices, dried goods, frozen and canned foods: classified and stored in separate designated areas of the warehouse.
  • Step 3. Food processing
    • Based on the menu and the number of servings, food processing is carried out according to the following procedure: the Head Chef determines the required portions, the Warehouse Keeper issues the ingredients, and the Main Cooks prepare dishes according to the menu.
    • The food processing process must ensure the following:
    • The area for processing raw food such as meat, fish, and seafood must be separated from the kitchen area to prevent bacterial contamination;
    • Salad and bakery areas must be separated from areas for ready-to-eat and non-ready-to-eat foods;
    • Use color-coded cutting boards to distinguish between raw and cooked foods;
    • All cooking utensils and containers must be cleaned and disinfected regularly.
  • Step 4. Food and meal preservation
    • Cooked food must be preserved using specialized equipment (such as food warmers or plastic wrap). Meals are portioned and served at scheduled times according to set standards.
    • Uncooked food must be preserved properly. Specifically:
      • For raw food such as meat and fish: keep refrigerated below 5°C if used within the day, or frozen if stored longer;
      • For vegetables, tubers, and fruits: store in coolers below 8°C and use within 24 hours for best quality;
      • For canned foods: store in a dry warehouse and follow the “first in – first out” principle;
      • For frozen foods: place immediately in freezers. When defrosting, follow proper thawing procedures and only use the required amount;
      • Eggs should be kept in coolers at proper temperature to extend shelf life.
    • All food in the kitchen must be labeled with product names and date tags for tracking purposes. Refrigerated storage must separate raw from cooked foods, and meat from fish. Regularly clean equipment, utensils, and food storage areas, and conduct frequent and periodic food inspections to ensure quality.

---

IV. Kitchen Cleaning Procedures

1. Essential Kitchen Cleaning Supplies in Food Processing Safety Documents

To clean the kitchen, housekeepers need to prepare the following basic items:

• Soft cloths, spray bottles, rubber gloves, sponges
• Multi-purpose cleaners and cleaning creams
• Floor cleaner
• Broom and mop

Prepare kitchen cleaning tools.

Additionally, for different kitchen areas, you will need specific cleaning tools. Therefore, you may also prepare: baking soda, salt, lemon, vinegar, warm water, toothpaste, glass cleaner, and disinfectant spray.

2. Kitchen Cleaning Sequence in Food Processing Safety Documents

• Cleaning Cabinets and Accessories
  • Cleaning Wooden Parts
    • Cleaning Natural Wood Cabinets
      • You can use a glass cleaner spray directly on the wooden surface of cabinet doors, then wipe dry with a soft cloth. However, if you are concerned about using too much glass cleaner, you can replace it with regular water and clean the cabinets more frequently. Next, use a disinfectant spray inside the cabinet compartments and wipe dry with a cloth, ensuring you do not forget to clean the cabinet handles.
    • Cleaning Industrial Wood Cabinets
      • Cleaning industrial wood cabinets is similar to cleaning natural wood ones. However, for acrylic cabinets, spray glass cleaner onto the cabinet surface, spread evenly, and use a glass wiper to remove the liquid. Then, wipe the remaining moisture with a dry cloth to keep the acrylic cabinet shiny and mirror-like.
  • Cleaning Cabinet Accessories
    • Cleaning Stainless Steel Racks
      • For stainless steel racks such as dish racks, pot holders, knife and cutting board racks, spice racks, etc., use diluted dishwashing liquid on a soft cloth to clean them thoroughly.
    • Cleaning the Sink
      • Baking soda is a highly effective cleaning agent and is commonly used in kitchens. To clean the sink, wet it first, sprinkle baking soda on the surface, let it sit briefly, then rinse clean.
      • Use an old toothbrush dipped in a little baking soda to scrub the strainer area, then rinse with water.
      • If the drain emits a bad odor, pour ½ cup of baking soda followed by a bit of white vinegar and then warm water. This will clean the drain and remove unpleasant smells. You can also pour a small amount of dish soap or scented liquid soap into the drain, leave it for 30 minutes, then flush with water to eliminate residue and odors.
      • Cleaning Around the Faucet: Use an old toothbrush dipped in a warm water and soap solution to scrub around the faucet, then rinse clean with water.
    • Cleaning Kitchen Backsplash Glass and Countertops
      • During cooking, grease and food odors easily stick to the backsplash glass and countertops. Therefore, clean these areas regularly, especially after cooking, to prevent buildup. Use a sponge soaked in warm soapy water to wipe in circular motions, then dry with a clean cloth or paper towel.
      • For stubborn stains, apply a paste of warm water and baking soda. Once it dries, remove the residue and wipe again with diluted lemon juice or vinegar for a polished finish.
• Cleaning Kitchen Appliances
  • Cleaning the Refrigerator
    • To keep the refrigerator operating efficiently and food fresh, cleaning is essential. First, remove all contents from the refrigerator. Once empty, wipe down surfaces with cleaning solution. Organize and group foods, placing near-expiry items in a separate area for easier access.
    • If the refrigerator has unpleasant odors, pour a small amount of vanilla extract into a bowl, soak a paper towel in it, and use the towel to wipe all interior surfaces. This simple method will refresh the refrigerator’s scent.
  • Cleaning the Blender
    • Fill the blender halfway with warm water, add a few drops of dishwashing liquid, close the lid, and blend for about 10 seconds. Then rinse thoroughly with warm water. This method cleans every corner of the blender within 30 seconds.
  • Removing Stove Grease and Buildup
    • Place the gas stove grate into a plastic bag, pour ¼ cup of ammonia inside, seal tightly, and leave overnight outdoors. The ammonia fumes will dissolve grease and grime, allowing easy cleaning with a cloth. For stovetop stains, apply a mixture of lemon juice, baking soda, and water; after 15–20 minutes, scrub and rinse clean.
  • Cleaning Control Knobs
    • If not cleaned properly, control knobs can harbor bacteria. Soak them in warm soapy water, rinse clean, and avoid using abrasive or ammonia-based cleaners to prevent fading the printed markings.
  • Cleaning the Oven
    • Use a damp cloth to wipe the oven interior, then coat the surface with a thin layer of baking soda. Leave for three hours, spray white vinegar, and let it sit for a few more hours. When the reaction completes, wipe clean with a sponge.
  • Deodorizing the Microwave with Lemon
    • Place thin lemon slices in a ceramic bowl with water. Microwave on high for three minutes to allow the lemon’s antibacterial properties to activate. The heat also loosens food residue, which can then be wiped away with a damp cloth, leaving the microwave clean and fresh.
  • Cleaning the Dishwasher
    • Remove all dishes, pour 200 ml of vinegar into the machine, and run a normal cycle. This simple cleaning tip removes even the most hidden stains and residue.
• Cleaning Kitchen Utensils
  • Using Salt, Lemon, and Vinegar to Remove Stubborn Stains
    • Salt, lemon, and vinegar are not only cooking ingredients but also excellent natural cleaning agents. Regularly scrubbing cast iron pans with salt will keep them shiny and clean. Pour vinegar into an ice cube tray, add lemon slices, and freeze. Wrap a frozen cube in a cloth to scrub stubborn stains on cabinets or copperware for a polished finish.
  • Cleaning Cutting Boards
    • Pour vinegar over the cutting board and wipe with a paper towel. Alternatively, rub a halved lemon with salt on the surface in circular motions, then rinse under running water.
  • Cleaning Burnt Pots and Pans
    • Fill the burnt pot or pan with water, add 1–2 pieces of chopped rhubarb, and boil for 2–3 minutes. Let it cool completely, then scrub clean—the residue will come off easily.
  • Cleaning Kitchen Floors
    • Sweep the kitchen floor, then mop using diluted floor cleaner for a spotless surface.

3. Creating Fragrance for the Kitchen in Food Processing Safety Documents

• After cleaning, you can freshen up your kitchen with this simple method for a relaxing and pleasant aroma:
  • Step 1: Slice 1–2 fresh oranges and add a few cinnamon sticks into a small pot.
  • Step 2: Add water and bring to a boil. The combination of cinnamon and orange essential oils will fill the kitchen with a warm, pleasant scent. Store the mixture in the refrigerator and reheat as needed.

---

V. Food Hygiene and Safety in Food Processing Safety Documents

According to Circular No. 30/2012/TT-BYT on food safety conditions for food service establishments, food safety requirements for collective kitchens are as follows:

1. Facilities, equipment, utensils, and personnel involved in food preparation must comply with Articles 1–4 of Circular No. 15/2012/TT-BYT dated September 12, 2012, of the Ministry of Health, stipulating general food safety conditions for food production and business establishments.
2. Kitchens must have designated areas for raw food preparation, cooking, food storage, dining, raw material warehouses, and packaged food storage; handwashing and restroom facilities must be separate. Kitchens receiving pre-cooked meals must have suitable designated areas based on the number of portions served.
3. Food processing areas must follow a one-way design; provide separate tools for handling raw and cooked foods; ensure clean utensils for dividing and serving food; use disposable gloves when directly handling food; and have equipment to prevent flies, cockroaches, and pests.
4. Dining areas must be well-ventilated, clean, and equipped with pest prevention devices; have at least one handwashing sink per 50 diners and one restroom per 25 diners.
5. Ready-to-eat and cooked foods must be displayed hygienically on surfaces at least 60 cm above the ground, with protection from dust and insects, and served with clean utensils.
6. Ice used for consumption must be produced from water that meets National Technical Regulation No. 01:2009/BYT on drinking water quality.
7. Maintain records of three-step food inspection as guided by the Ministry of Health; store food samples for at least 24 hours after preparation in proper conditions.
8. Provide sealed waste containers with lids, collect and dispose of waste daily, and ensure wastewater is collected in a closed system without environmental contamination.

Inspection Guidelines:

Step 1: Inspection of Incoming Raw Materials
Food ingredients imported for processing must be inspected and recorded to facilitate management and ensure compliance with food safety requirements. The following information must be checked and monitored:

• Date and time of raw material receipt.

• Name of the food ingredient.

• Quantity received – Source of the food (accompanied by relevant documents).

• For fresh foods: meat must have identification numbers and veterinary certificates attached, as well as suitable packaging materials.

• For processed and packaged foods: brand name, type of packaging (sealed/unsealed), and expiration date.

• Sensory condition of the food material upon receipt – Storage conditions.

• Accompanying test results (if any).

Step 2: Inspection During Preliminary and Main Processing
During food preparation and cooking, the following information must be checked and monitored:

• Meal shift, date, and time of processing.

• Name of the food ingredient.

• Quantity used for processing.

• Duration of preliminary processing.

• Time when cooking is completed.

• Time when food distribution is completed.

• Time when consumption begins.

• Sensory condition before processing.

• Storage conditions before processing.

• Equipment and containers used for serving and packaging.

Step 3: Inspection Before Consumption
Before meals, the following information must be inspected and monitored:

• Meal shift / date and time of consumption.

• Names of dishes / menu items.

• Quantity / number of menu items.

• Source of the dishes: clearly specify the origin of each food item.

• Conditions of food preparation.

• Food storage conditions: covering, temperature control, etc.

• Consumption time: calculated from the time of completion of processing or from the time of purchase until consumption.

• Sensory condition of the dishes.

• Accompanying test results on food quality and safety (if any).

• Sample retention: retain representative samples of all dishes, including beverages, snacks, and packaged foods.

1. Food Hygiene and Safety Standards for Kitchens

• Food hygiene and safety standards for kitchens are evaluated under Decision No. 4128/2001/QD-BYT dated October 3, 2001, by the Ministry of Health, including the following criteria:

Facility Sanitation Conditions

• Location: Kitchens and dining areas must be away from restrooms and pollution sources.
• One-way design: The kitchen must have a one-way layout from raw materials to finished food.
• Walls and floors: Built with waterproof, easy-to-clean materials such as tiles.
• Dining area: Ventilated, clean, and free from flies, insects, and rodents.
• Trash bins: Must have lids to prevent food waste from spilling.
• Restrooms: Conveniently located, well-ventilated, and separate from kitchen and dining areas.
• Changing room: Provided for employees to change protective clothing before and after work.
• Drainage system: Unclogged, covered, and without stagnant water.
• Clean water supply available for food preparation.
• Possess a valid Food Hygiene and Safety Certificate.

Utensil Sanitation

• Dishes and bowls must be clean and dry.
• Separate cutting boards and knives for raw and cooked food.
• Utensil holders and racks must be kept clean, not placed on the floor or damp areas.
• Dishwashing liquid must meet hygiene standards.
• Serving utensils must be sanitary.
• Cooking utensils must be durable, non-toxic, and easy to clean.

Conditions for the Origin and Preservation of Food

• The origin of purchased food: there must be a contract or document proving the origin of the purchased food.
• Menu: clearly specifies the dishes served during the day.
• Sample storage of processed food: must comply with regulations, fully showing information on the meal label; storage date and time; name of stored food sample; weight/volume; storage temperature; name and signature of the sampler.

2. Knowledge and Practice of Food Hygiene and Safety for Food Processing Staff

The Decision No. 43/2005/QĐ-BYT dated December 20, 2005 by the Minister of Health stipulates “Requirements for food hygiene and safety knowledge for individuals directly engaged in food production and business.” This is the standard for assessing the knowledge and practices of food safety and hygiene among employees.

• Knowledge of Food Hygiene and Safety Hazards
  • Food contamination hazards include: chemical, biological, physical, and unknown hazards.
  • Metal fragments, glass shards, wood splinters, grit, soil, pebbles, bones, hair, etc., are classified as: chemical, physical, biological, or other hazards.
  • Food contamination sources include: contaminated hands of food handlers; insects and animals; contaminated raw materials; unsanitary processing equipment.
  • Microorganisms that cause food spoilage thrive at temperatures: from 4°C to 40°C, from 5°C to 60°C, from 10°C to 100°C, unknown, or not concerned.
  • Correct knowledge: microorganisms causing food spoilage develop within the temperature range of 5°C to 60°C.
  • Food handlers with tuberculosis are allowed to process food: yes or no.
• Knowledge of Food Hygiene and Safety Conditions
  • To ensure food hygiene and safety, food service establishments must meet conditions related to: facilities, equipment and tools, and personnel.
  • Principle of kitchen design: one-way principle, two-way principle, or others.
  • The kitchen floor and food preparation walls should be covered with non-absorbent ceramic tiles that are easy to clean.
  • Placement of garbage bins and food containers with tight lids: in the dining area and kitchen; at the entrance; unknown.
  • Distance between stored food on shelves and the ground: at least 60 cm; over 30 cm; any height; unknown.
  • Kitchen and processing area drainage: must be ventilated, non-clogged; covered or enclosed; unknown.
  • Containers for clean water used in food processing and handwashing: must be cleaned regularly; cleaned only when dirty; unknown.
  • Other utensils such as knives, cutting boards, pots, and tools: must be cleaned immediately after use; cleaned only before use; unknown.
  • Dining rooms and tables must be hygienic: well-lit, well-ventilated; free of insects, flies, and rodents; regularly cleaned; other.
• Knowledge of Food Processing and Preservation
  • Cooked food must be stored hygienically: in glass cabinets or covered with nets or lids to prevent dust and insects.
  • Correct practice: cooked food must be stored in glass cabinets or covered with nets or protective lids.
    • Storage time of cooked food at room temperature: more than 1 hour; not more than 2 hours; more than 3 hours; other.
    • Storage of cooked and raw food: stored separately; stored together; other.
  • Correct practice: cooked and raw food must be stored separately.
    • Hygienic thawing methods: in the refrigerator compartment, soaked in clean water, in a microwave oven, or no thawing needed.
  • Correct knowledge: thawing should be done in the refrigerator, in clean water, or in a microwave oven.
    • Cooked meat and seafood dishes that are left for over two hours before serving must be reheated before serving.
    • Food ingredients and additives must have a clear origin and be approved by state authorities.
    • Fresh vegetables and fruits must be washed thoroughly under running water at least three times.
    • Cooking utensils (knives, cutting boards, tongs, spoons, etc.) used for raw and cooked food must be kept separate.
    • Spoiled or contaminated food from dead animals must not be used for processing.
• General Knowledge of Food Handlers on Food Safety and Hygiene
  • Food Safety and Hygiene Practices of Kitchen Staff
  • Do not wear jewelry while preparing food.
  • Nails must be kept short and unpolished.
  • Staff must wear protective clothing: aprons, hats, and masks during food preparation.
  • Employees with hand fungus, dermatitis, or infectious diseases are not allowed to handle food.
  • Eating, drinking, or spitting in food preparation areas is strictly prohibited.

3. Rapid Borax Test Kit – Code BK 04 (in Food Processing Safety Materials)

• Composition: A box of 50 test sticks, each with a test paper and a color scale for result comparison.
  • 01 bottle of buffer solution.
  • 01 instruction manual.
• Instructions:
  • Sample preparation: For solid food, take about 2g (cut into pea-sized pieces), place in a cup, add 20 drops of buffer solution, crush the sample, and let it sit for 5–10 minutes.
  • Testing: Dip the test paper into the prepared sample, remove it, and place it flat to read the result.
• Result interpretation:
  • Positive: If the test paper changes from bright yellow to reddish-brown (different from the printed reference color).
  • Negative: If there is no color change on the test paper.
• Notes:
  • Only immerse the lower part of the test paper.
  • Color intensity depends on the amount of borax present in the sample.
  • If borax content is low (50 mg/kg), read the result after about 30 minutes.

4. Rapid Formaldehyde Test Kit – Code FT04 (in Food Processing Safety Materials)

• Composition:
  • Box containing 20 FT04 test bags, each with a reagent and a printed color scale for comparison and expiration date.
  • 01 instruction manual.
• Instructions:
  • Sample preparation:
    • For solid samples, take about 2g (cut into corn-sized pieces). For seafood, use soaking water as the test sample.
    • Cut open the bag, place the sample inside, add 3ml of clean water, shake well. For soaking water, fill up to the second test mark.
    • Break the ampoule in the colored tube, shake until the solution turns yellow.
    • Break the ampoule in the white tube, shake again, and observe color changes.
• Result interpretation:
  • Positive: The solution turns pink-purple (same as the printed reference color), indicating the presence of Formaldehyde.
  • Negative: The solution remains yellow.
• Notes:
  • The color intensity varies with Formaldehyde concentration.
  • Avoid direct contact with chemicals; rinse immediately with clean water if contact occurs.

5. Food Handlers’ Knowledge in Collective Kitchens (in Food Processing Safety Materials)

• Knowledge of Food Hygiene and Safety Hazards
  • There are three main types of food safety hazards: chemical, biological, and physical. These hazards can alter food and negatively impact health. Major contamination sources include dirty hands, insects, animals, contaminated raw materials, and unsanitary processing tools. Microorganisms can survive and multiply across a wide temperature range, making everyday food a potential environment for microbial growth. Awareness of this helps reduce risks.
• Knowledge of Food Hygiene and Safety Conditions
  • To achieve food safety conditions, three factors are required: facilities, equipment, and personnel. Proper placement of trash bins in collective kitchens is important—preferably near food preparation or dining areas. Food shelves should be elevated, trash bins covered, and drainage systems sealed properly.
  • Frequent cleaning of storage containers and processing tools (knives, cutting boards, scissors, etc.) is essential. Cleaning should be done regularly, whether or not the tools are in use. Dining rooms must be well-lit, well-ventilated, insect-free, and hygienic.
• Knowledge of Food Processing and Preservation
  • Even well-prepared food can become unsafe if not properly preserved. Food should be kept in covered containers to prevent exposure to dust and insects. Cooked and raw food must be stored separately. Proper defrosting techniques and using ingredients and additives of verified origin are vital for food safety.
  • Fresh vegetables and fruits should be washed thoroughly under running water to remove pesticide residues. Separate knives and cutting boards must be used for raw and cooked food.
• Food Hygiene and Safety Conditions in Collective Kitchens
  • To operate safely, collective kitchens must meet standards regarding infrastructure, equipment, and food sourcing and preservation. These requirements help minimize food safety risks and protect workers’ health—an essential factor in maintaining productivity and quality of life.
• Borax and Formaldehyde in Collective Kitchens
  • Borax, though used to improve food elasticity and freshness, is banned due to its health risks. Some still use it for profit, but its use in collective kitchens is strictly prohibited as it endangers workers’ health and productivity.
  • Regular training on food hygiene and safety should be provided for kitchen staff, with supervision from medical and management authorities to ensure compliance.
  • Employees without valid health certificates or food safety training must be promptly trained and certified.
  • Regulatory agencies must conduct regular inspections of hygiene conditions, personal hygiene, and food storage practices. Random sampling or rapid tests should be carried out to detect violations and prevent food poisoning incidents.

---

Chapter V: Further References

1. Occupational Safety Training Services – Group 3 Certification

---

2. Occupational Safety Test – Group 3

• Group 3 Occupational Safety Multiple-Choice Test

---

3. Occupational Safety Training Service Price List

• View Details

---

4. Download Documents

• Download Occupational Safety Training Document for Working in Collective Kitchens