If your employees work in painting, foam-blowing, or manufacturing polyurethane products like chemicals, coatings, and adhesives, they may be exposed to isocyanates. A new OSHA National Emphasis Program (NEP) for isocyanates will increase enforcement and compliance assistance for a 3-year period in general industry, construction, and maritime industries.

Isocyanates, a class of chemicals often used in materials including paints, varnishes, building insulation, and more, are the raw materials that make up all polyurethane products, and they include compounds classified as potential human carcinogens. Isocyanate exposure can cause irritation of the skin and mucous membranes, chest tightness, and difficulty breathing, and can lead to occupational asthma and other lung problems. According to OSHA, deaths have occurred due to both asthma and hypersensitive pneumonitis from exposure to these dangerous compounds.

Job functions that may expose workers to isocyanates include:

• Painting, varnishing, and spray-on coating operations;
• Auto body repair;
• Foam blowing; and
• Manufacturing polyurethane-containing products, including surface coatings, furniture, car seats, shoes, foam mattresses, under-carpet padding, and more.

Minimize exposure to isocyanates

Whether or not your site is inspected as part of OSHA’s new emphasis program, you should take steps to reduce your employees’ exposure to isocyanates:

• Find a less-toxic alternative. More options are becoming available. If you have searched for alternatives in the past but not found them, you should take another look.
• Warn workers. By the time an individual can smell isocyanates, their concentration in the air typically exceeds legal limits and has become dangerous. All employees who could be exposed should receive appropriate hazard communication training.
• Control airborne concentrations. Protect workers by enclosing processes that use isocyanates. To contain hazardous vapors, an enclosed process should be kept at a negative pressure inside. Ventilation should be built into the enclosure, and the ventilation system should be regularly tested and maintained.
• Control respiratory exposures. Operators inside enclosed areas need to be part of a complete respiratory protection program.
• Control skin exposures. Workers should wear full-body, chemical-resistant suits with gloves when working with isocyanates. Because the chemical will break down and penetrate protective clothing, protective suits and gloves should be replaced frequently.

Relevant OSHA standards

Depending on the specific chemical, isocyanates can be covered under a variety of OSHA standards, including its Process Safety Management Standard for highly hazardous chemicals and its permissible exposure limits (PELs) for air contaminants.

In addition, employers whose workers are exposed to isocyanates are subject to OSHA’s Hazard Communication Standard, which requires businesses to have a written program, labels, and material safety data sheets (MSDSs) and/or safety data sheets (SDSs) and to provide training to workers on how to access and interpret information about chemical hazards in the workplace.