* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * INFORMATION ALERT * * * * Produced by: Saskatchewan Human Resources, * * Labour and Employment * * Provided by: Canadian Centre for Occupational Health and Safety * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * SPRAYING OF ISOCYANATE PAINTS AND PRIMERS *** REQUIREMENTS IN AUTOBODY SHOPS: *** - Workers must wear air-supplied respirators when spraying paints and primers containing isocyanates. - Airborne isocyanate must be prevented from entering areas where workers are unprotected by air-supplied respirators. - All spraying of isocyanate paints must take place in a paint booth. The use of paint booths for the spraying of isocyanate primers is recommended. - If any isocyanate primer is sprayed outside of a paint booth, then an area separated from other workers equipped with a ventilation system sufficient to prevent the spread of isocyanates outside that area shall be used. *** PROPERTIES AND HEALTH EFFECTS OF ISOCYANATES: *** Isocyanates are highly reactive chemical typically found in the hardener of two-part paints and primers. Isocyanates are present in two forms, monomer and prepolymer. Frequently, the isocyanate monomer content is indicated in product data information, but this is only a small fraction of the total unreacted isocyanate present in hardeners. Both forms of unreacted isocyanate present a risk to health when they enter the air during paint or primer spraying. The major health effect from isocyanates is associated with the inhalation of unreacted airborne isocyanate. Such exposure can cause coughing, chest tightness, fever, fatigue and sensitization. Sensitization means that further exposure to even very small amounts of isocyanates will cause distressing asthma-like reactions. One exposure to a high airborne concentration or several exposures to lower concentrations, may result in sensitization. There is no proven method for predicting whether any particular person will become sensitized due to isocyanate exposure. In May, 1984, the Ocupational Health and Safety Branch informed autobody shops that air-supplied respirators were requried when spraying paints containing isocyanates. Testing by the Branch has shown that air-supplied respirators are also necessary when primers containing isocyanates are sprayed. Even priming jobs of less than three minutes duration conducted in the open shop will product sufficient airborne isocyanate to present a risk of overexposure to the sprayer and other workers in the shop. All types of spray guns used to apply primers have been found to contaminate the open shop if a separately ventilated spray area or spray booth is not used. *** AIR SUPPLIED RESPIRATORS: *** When spraying paints or primers containing isocyanates, the sprayer must wear an air-supplied respirator which is approved by the United States National Institute of Occupational Safety and Health (NIOSH) as Type C constant flow or pressure demand. Respirators with approvals from testing agencies other than NIOSH are accepteable if the criteria for their approval is deemed to be sufficient by the Saskatchewan Occupational Health and Safety Branch. Air must be supplied at a rate of 115 litres per minute (four cubic feet per minute) to a loose fitting facepiece. The air supply rate should not exceed 425 litres per minute (15 cubic feet per minute). Breathing air may be provided by a separate electrical compressor which draws air from an uncontaminated source. The compressed plant air may also be used if filters are provided to remove the water and oil and its breakdown products. The compressor must be kept in good repair and prevented from overheating so that carbon monoxide will not be produced. An uncontaminated source of air must be used for the compressor (elevated carbon monoxide concentrations measured by the Branch in the plant air of autobody shops have been due to the compression of shop air previously contaminated with vehicle exhaust. The line feeding the spray gun may be split to also supply the air- fed respirator, provided that the air is first filtered in the prescribed manner and the air is fed to the respirator through a regulator which delivers the air to the respirator at the prescribed flow rates. Infogram HU10/24/89 * * * * * * * * * * * * * * * * * * * * * * * *