Working environment factors
How does Nitrogen Oxide affect workers’ health?
Jan
Nitrogen oxides (NOx) are a “silent killer” in the factory environment, severely affecting the health of workers. They cause respiratory and cardiovascular diseases and many other dangerous consequences. How can we identify and minimize the risks? Let’s find out now to protect your health at work!
1. What are Nitrogen oxides?
Nitrogen oxides (NOx) are a group of gaseous compounds containing nitrogen and oxygen, primarily including two main types: nitrogen monoxide (NO) and nitrogen dioxide (NO₂). These are colorless or reddish-brown gases, typically generated from the combustion of fossil fuels in industrial plants, vehicles, and high-temperature manufacturing processes.
Under normal conditions, NO is unstable and easily oxidized to NO₂ upon contact with oxygen in the air. NO₂ is a toxic gas with a pungent odor that strongly irritates the respiratory system and is a major contributor to air pollution, including photochemical smog and acid rain.
NOx not only has a negative impact on the environment but also seriously affects human health, especially for workers in manufacturing plants that use these chemicals. Therefore, understanding what NOx is and how to control it in the workplace is crucial to protecting health and minimizing occupational risks.
| No. | Chemical Name in Vietnamese | Chemical Name in English | HS Code | CAS Number | Chemical Formula |
| 1. | Nitơ oxit | Nitrogen oxides | 28112290 | 11104-93-1 | NOx |
See more chemical safety training services under Decree 113/2017/ND-CP
REGISTER FOR CHEMICAL SAFETY TRAINING UNDER DECREE 113
2. Where do Nitrogen oxides originate from in the production process?
In industrial production processes, NOx is often generated from the combustion of fossil fuels such as coal, oil, and natural gas. When temperatures in furnaces or heating equipment are high, nitrogen in the air reacts with oxygen to form nitrogen oxide compounds. Power plants, industrial boilers, and heating systems that use fossil fuels are common sources of NOx emissions.
Additionally, in the chemical manufacturing industry, the oxidation of ammonia to produce nitric acid also generates a large amount of NOx. This is a crucial step in the production of fertilizers, explosives, and many other chemical products. Furthermore, chemical reactions in the production of paints, adhesives, and plastics can produce NOx gas as a byproduct.
Another source comes from the process of oxy-acetylene or plasma metal cutting and welding. When a high-temperature flame comes into contact with the air, nitrogen and oxygen combine to form NOx. In metallurgical and metal fabrication plants, this activity occurs frequently, increasing the concentration of NOx in the work environment.
The internal combustion engines of industrial machinery also contribute significantly to the amount of NOx emitted. Internal transport vehicles such as forklifts, tractors, or diesel-powered generators often produce exhaust containing NOx, especially in enclosed spaces like workshops or warehouses.
3. Industries that use Nitrogen oxides in production
The chemical industry is one of the sectors that most commonly use NOx, especially in the production of nitric acid. This chemical is a crucial raw material for producing fertilizers, explosives, and many other organic compounds. During the ammonia oxidation process, a large amount of NOx is generated, requiring strict exhaust gas treatment systems to limit the impact on the environment and workers’ health.
The metallurgy and metal fabrication sectors also have a significant presence of NOx. During welding and cutting with oxy-acetylene or plasma, the high-temperature reaction between oxygen and nitrogen in the air creates NOx gas. Plants producing steel, aluminum, and other metals frequently use these methods, increasing the risk of exposure to toxic gas in the work environment.
The manufacturing industries for paint, adhesives, and synthetic plastics are also associated with the use of NOx. Some chemical reactions in the process of creating these products can generate NOx gas as a byproduct. Particularly in industrial paint manufacturing facilities, these emissions can accumulate in enclosed spaces, affecting the air quality inside the workshop.
Thermal power plants and the cement manufacturing industry are sectors with high levels of NOx emissions due to the high-temperature combustion of fossil fuels. Coal, oil, and natural gas are used as the main energy sources, producing large quantities of NOx from the reaction between nitrogen and oxygen under extreme temperature conditions. This is especially common in the clinker kilns of the cement industry and large-scale industrial boilers.
4. How do Nitrogen oxides affect workers?
When NOx gas enters the body through the respiratory tract, it can cause severe irritation to the lungs and airways. With long-term exposure to low concentrations, workers may experience symptoms such as coughing, difficulty breathing, sore throat, and an increased risk of chronic bronchitis. In particular, NO₂ can penetrate deep into the alveoli, impairing lung function and making the respiratory system more sensitive to other pathogens.
The impact of NOx is not limited to the respiratory system but also negatively affects the cardiovascular system. At high concentrations, this gas can cause inflammation, reduce the amount of oxygen in the blood, and increase the risk of diseases such as high blood pressure, arrhythmia, and coronary artery disease. Workers in environments with high NOx concentrations may often experience fatigue, dizziness, and decreased stamina due to a lack of oxygen supply to the body.
Eyes and skin can also be damaged by exposure to NOx, especially NO₂, due to its corrosive and irritating properties. Workers may feel eye irritation, tearing, redness, and itchy skin when working in an environment containing this gas. If there is direct contact with high concentrations over a long period, the risk of dermatitis and corneal damage may increase.
In addition to acute effects, long-term exposure to NOx can lead to more serious health problems, including the risk of developing chronic obstructive pulmonary disease (COPD) and worsening pre-existing conditions like asthma. Studies also indicate that long-term inhalation of high concentrations of NOx can increase the risk of stroke and other dangerous cardiovascular complications.
5. Permissible safe concentration of Nitrogen oxides for human exposure
Safe NOx concentration limits in the workplace are regulated by many international organizations to protect workers’ health. According to the U.S. Environmental Protection Agency (EPA), the one-hour average exposure limit for NO₂ is 100 ppb (parts per billion). Meanwhile, the World Health Organization (WHO) recommends that the annual average concentration should not exceed 40 µg/m³ to reduce the risk of respiratory and cardiovascular diseases.
The U.S. Occupational Safety and Health Administration (OSHA) sets the occupational exposure limit for NO at 25 ppm (parts per million) for an 8-hour workday. For NO₂, this limit is lower, at only 5 ppm, due to its higher toxicity. The U.S. National Institute for Occupational Safety and Health (NIOSH) also recommends a short-term exposure limit for NO₂ not to exceed 1 ppm to avoid immediate effects such as lung irritation and reduced respiratory function.
In Vietnam, the National Technical Regulation on Ambient Air Quality (QCVN 05:2013/BTNMT) specifies the limit for NO₂ concentration in the air as 200 µg/m³ for one hour and an annual average of 40 µg/m³. In the workplace, exposure standards for toxic gases are often based on international guidelines, requiring businesses to implement monitoring and control measures for NOx concentrations to ensure worker safety.
On a basic level, if working in an industrial environment, it is important to adhere to safety standards and limit exposure to Nitrogen oxides. Organizations such as the Occupational Safety and Health Administration (OSHA) in the United States provide guidelines and safety principles to protect workers from the negative impacts of chemical substances.
6. Measures to minimize the effects of Nitrogen oxides on workers’ health
Controlling emission sources is a key measure to minimize the impact of NOx on workers’ health. In plants that use furnaces or internal combustion engines, optimizing the combustion process to lower the burning temperature can limit the formation of NOx. Using cleaner fuels, such as natural gas instead of coal or diesel, also helps reduce harmful emissions.
Ventilation and exhaust gas treatment systems play a crucial role in maintaining air quality in workshops. Installing air filtration devices like NOx absorbers with activated carbon or NOx reduction systems using ammonia (SCR – Selective Catalytic Reduction) helps reduce the concentration of toxic gases before they are released into the environment. At the same time, ensuring good ventilation helps dilute NOx concentrations in the air, reducing the risk of direct exposure for workers.
Personal protective equipment is a necessary measure in high-risk environments. Workers should use specialized respirators capable of filtering toxic gases, safety glasses to avoid eye irritation, and protective clothing to reduce the risk of NOx exposure. Additionally, equipping workers with portable gas detectors helps to quickly detect abnormal increases in NOx, allowing for timely response measures.
Training and raising awareness among workers about the dangers of NOx and how to prevent them are key to minimizing risks. Regular training programs help workers recognize the danger signs of toxic gas exposure and understand emergency response procedures. Establishing safe work procedures, including periodic inspections of exhaust treatment systems and protective equipment, contributes to the long-term health protection of workers.
Occupational safety training: Workers need to be trained and educated on the risks and safety measures when working with this type of chemical. This training should be provided periodically and regularly to ensure understanding and proper compliance with safety rules.
Periodically organize occupational environment monitoring in factories and enterprises, collect and analyze factors harmful to workers, and thereby adjust to reduce hazard levels to prevent occupational diseases for them.
7. National Occupational Environment Monitoring Center
The occupational environment monitoring center of Nam Viet is a professional unit specializing in monitoring and measuring the quality of the occupational environment across all provinces in Vietnam. With a team of experienced monitoring specialists, the center uses modern measuring equipment, ensuring accuracy and reliability.
REGISTER FOR OCCUPATIONAL ENVIRONMENT MONITORING SERVICE
In addition to providing monitoring services, the center also assists clients in planning, handling, and tracking occupational environment issues. With the motto “the customer is the center,” the center focuses on customer satisfaction, meets all customer needs, and commits to providing the best solutions for businesses.
With investment in technology, engineering, and human resources, Nam Viet’s monitoring center has become one of the reputable units in the field of occupational environment monitoring in Ho Chi Minh City with the following objectives:
- We always value our brand reputation and the quality of our products and services.
- We provide our customers with the best and most suitable solutions possible.
- With a team of experienced Masters and Engineers with a desire to protect the environment and benefit businesses.
- With the Nam Viet Environmental Monitoring team, your company will receive professional service from experts in the monitoring field. At the same time, you will get the best cost incentives.
8. Quotation for occupational environment monitoring
To help businesses conduct occupational environment monitoring professionally and effectively, Nam Viet offers our valued customers a price list for occupational environment monitoring services that is high-quality and reasonably priced.
- Our quotation provides detailed information on the prices of the monitoring services we offer. This includes costs related to travel, measurement, analysis, and reporting of results. Customers can be completely assured of the accuracy and reliability of the monitoring result reports we provide.
- We are committed to always offering the most competitive and reasonable prices on the market, and we are also always ready to provide consultation and answer any questions about our monitoring services quickly and professionally.
- With Nam Viet’s quotation, customers can easily choose service packages that suit their needs. We are committed to bringing our customers the highest satisfaction with professional service quality.
