Working environment factors
How does toluene di-isocyanate affect workers’ health?
Apr
Toluene di-isocyanate (C9H6N2O2) is a hazardous chemical commonly used in manufacturing plants. This article provides an overview of its effects on workers’ health, from short-term symptoms to long-term risks associated with frequent exposure.
1. What is Toluene di-isocyanate?
Toluene di-isocyanate (TDI), with the chemical formula C9H6N2O2, is an organic compound belonging to the isocyanate group, widely used in industry to produce polyurethane. Polyurethane is a type of polymer with diverse applications, including the production of foam, coatings, adhesives, elastomers, and many other products.
TDI typically appears as a clear, colorless, or pale yellow liquid with a characteristic pungent odor. It is not soluble in water but can mix with many organic solvents such as alcohol, acetone, benzene, and kerosene. TDI mainly exists in two isomers, 2,4 and 2,6, with common market mixtures in ratios of 80/20 or 65/35.
Understanding TDI is essential, especially for workers in industries using this chemical, to ensure safety and health in the workplace.
| No. | Chemical name in Vietnamese | Chemical name in English | HS Code | CAS Number | Chemical formula |
| 1. | Toluene di-isocyanat | Toluene di-isocyanate | 29291090 | 584-84-9; 91-08-7 | C9H6N2O2 |
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2. Sources of Toluene di-isocyanate in the production process
In the production of Toluene di-isocyanate (TDI), the main sources arise from the chemical steps in the synthesis process. TDI production is typically carried out through the phosgenation method, which includes the following steps:
First, carbon monoxide (CO) and chlorine (Cl₂) react to produce phosgene (COCl₂). Next, toluene (C₆H₅CH₃) reacts with nitric acid (HNO₃) to produce dinitrotoluene (DNT). The DNT is then hydrogenated (H₂) to form toluene diamine (TDA). Finally, TDA reacts with phosgene to produce TDI.
During this process, TDI can be released as a gas or fine particles, especially in stages such as melting, mixing, or heating materials containing isocyanates. This may lead to the release of TDI into the working environment, particularly in chemical plants.
In addition, during TDI storage and transportation, improper handling can cause leaks or release of TDI vapors into the air, posing risks to workers and the surrounding environment.
3. Industries using Toluene di-isocyanate in production
Toluene di-isocyanate (TDI) is an important chemical in the polyurethane manufacturing industry and is widely used across various sectors.
In the automotive industry, TDI is used to produce interior components such as seats, dashboards, and soundproofing parts, thanks to its ability to create lightweight and durable materials.
The construction industry also applies TDI in producing insulation materials such as foam insulation for walls and roofs, helping save energy and improve thermal efficiency in buildings.
In addition, TDI is used in furniture manufacturing, particularly in products such as mattresses and sofas, due to the elasticity and durability of polyurethane.
In paints and coatings, TDI is a key ingredient in producing polyurethane paints, applied in many areas such as industrial coatings, automotive paints, and wood finishes, due to its ability to form durable, abrasion-resistant coatings. TDI is also used in the production of adhesives and sealants, playing a vital role in bonding and protecting components in various industrial applications.
4. How Toluene di-isocyanate affects workers
Exposure to Toluene di-isocyanate (TDI) in the workplace can cause serious health effects, particularly to the respiratory system. These effects may occur immediately or develop gradually over time, depending on the level and duration of exposure.
One of the main effects of TDI exposure is respiratory problems, including rhinitis, sore throat, coughing, shortness of breath, and wheezing. These symptoms may appear immediately after exposure or after prolonged periods. Notably, TDI is known to be an agent causing occupational asthma, with incidence rates reaching 5–6% in the early years of the industry, depending on the level of technical control and workplace practices.
Long-term exposure to TDI can lead to respiratory sensitization, making workers more prone to allergic reactions to other substances, even at low concentrations. This may cause symptoms such as shortness of breath, wheezing, and chest tightness, occurring either immediately or shortly after exposure.
Studies also indicate that prolonged exposure to TDI can reduce lung function, increase the risk of chronic respiratory diseases, and may lead to death if not controlled and treated promptly.
To protect workers’ health, it is essential to implement engineering controls, use personal protective equipment, and comply with occupational safety regulations when working with TDI.
5. Safe exposure limits for Toluene di-isocyanate
Currently, no specific information on safe exposure limits for Toluene di-isocyanate has been found in Vietnamese legal documents.
According to the U.S. Occupational Safety and Health Administration (OSHA), the concentration of Toluene di-isocyanate (TDI) in the workplace must not exceed 0.02 ppm (0.14 mg/m³) at any time during the work shift. OSHA also sets the permissible 8-hour time-weighted average (TWA) at 0.005 ppm (0.04 mg/m³) and the short-term exposure limit (STEL) at 0.02 ppm (0.15 mg/m³) over any 15-minute period.
However, organizations such as the U.S. National Institute for Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH) recommend even lower exposure limits to protect workers’ health. Specifically, NIOSH suggests a 10-hour TWA limit of 0.005 ppm (0.036 mg/m³) and a short-term limit of 0.02 ppm (0.14 mg/m³) over any 10-minute period.
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At a basic level, when working in an industrial environment, complying with safety standards and limiting exposure to Toluene di-isocyanate is important. Organizations such as the U.S. Occupational Safety and Health Administration (OSHA) provide guidelines and safety principles to protect workers from the harmful effects of chemicals.
6. Measures to minimize the impact of Toluene di-isocyanate on workers’ health
To minimize the effects of Toluene di-isocyanate (TDI) on workers’ health, a combination of technical, administrative, and personal protective measures should be applied.
First, controlling the source of TDI emissions is crucial. Local exhaust ventilation systems should be installed in areas where TDI vapors are released, such as melting, mixing, or heating materials containing isocyanates, to limit TDI concentration in the air. Using sealed equipment and effective exhaust systems also helps minimize the spread of TDI into the workplace.
The use of personal protective equipment (PPE) is essential. Workers should be provided with gas masks, protective gloves, and coveralls to prevent direct contact of TDI with the skin and respiratory tract. PPE should be inspected and maintained regularly to ensure maximum protection. Especially for workers directly handling TDI, full protective suits should be worn to minimize exposure.
Organizing occupational safety training is also critical. Workers should be educated on the risks and hazards of TDI, as well as the correct use and storage of PPE. Regular training sessions should be conducted to improve awareness and skills in preventing and responding to TDI-related incidents.
Monitoring and testing TDI concentrations in workplace air is necessary. Environmental monitoring measures should be implemented to promptly detect exposure levels exceeding permissible limits, allowing timely intervention to protect workers’ health.
Applying all these measures together will help significantly reduce the impact of TDI on workers’ health, ensuring a safe and efficient working environment.
Occupational safety training: Workers should be trained and educated on the risks and safety measures when working with this chemical. Such training should be provided periodically to ensure understanding and compliance with safety rules.
Regular workplace environmental monitoring should be conducted in factories to collect and analyze harmful factors for workers, then adjust to reduce hazards and prevent occupational diseases.
7. National Center for Occupational Environment Monitoring
Nam Viet’s Occupational Environment Monitoring Center is a professional unit specializing in monitoring and measuring workplace environmental quality nationwide across Vietnam. With a team of experienced monitoring specialists, the center uses modern measuring equipment to ensure accuracy and reliability.
REGISTER FOR OCCUPATIONAL ENVIRONMENT MONITORING SERVICES
In addition to providing monitoring services, the center supports clients in planning, handling, and tracking workplace environmental issues. With the motto “customers at the center,” the center prioritizes customer satisfaction, meets all customer needs, and is committed to delivering the best solutions for businesses.
With investments in technology, equipment, and human resources, Nam Viet’s monitoring center has become one of the reputable units in occupational environment monitoring in Ho Chi Minh City, with the following goals:
- We always value brand reputation and the quality of our products and services.
- We provide customers with the best and most suitable solutions possible.
- Alongside a team of experienced Masters and Engineers, we aim to protect the environment and benefit businesses.
- With Nam Viet’s Environmental Monitoring Team, your company will receive professional service from experts in the field, along with the best cost benefits.
8. Occupational Environment Monitoring Service Pricing
To help businesses conduct professional and effective workplace environmental monitoring, Nam Viet offers customers a detailed pricing table for occupational environment monitoring services with high quality and reasonable costs.
- Our monitoring service price list provides detailed information on the costs of the services we offer, including expenses for transportation, measurement, analysis, and reporting. Customers can rest assured about the accuracy and reliability of the monitoring reports we provide.
- We are committed to offering the most competitive and reasonable prices on the market and are always ready to quickly and professionally answer any questions about our monitoring services.
- With Nam Viet’s service pricing, customers can easily choose service packages that suit their needs. We are committed to delivering the highest satisfaction with our professional service quality.
