Phosgene (COCl₂) is described by the Agency for Toxic Substances & Disease Registry (ATSDR) as a colorless nonflammable gas that has the odor of freshly cut hay. It is a manufactured chemical and as a gas at room temperature (70º F) is heavier than air, but is sometimes stored as a liquid under pressure or refrigeration.

ATSDR reports it is used in the manufacture of other chemicals such as dyestuffs, isocyanates, polycarbonates and acid chlorides; it is also used in the manufacture of pesticides and pharmaceuticals. Phosgene can also be used to separate ores. In World War 1 it was used as a chemical weapon as a choking agent and is known by its military designation CG.

The National Institute for Occupational Safety and Health (NIOSH) states that workers may be harmed from exposure to phosgene. Exposure may cause irritation to the eyes, dry burning throat, vomiting, cough, foamy sputum, breathing difficulty and chest pain; and when a liquid: frostbite. The level of exposure depends upon the dose, duration and work being done. The Centers for Disease Control and Prevention (CDC) reports that exposure to phosgene may also cause delayed effects that may not be apparent for up to 48 hours.

NIOSH shares some examples of workers that may be at risk of being exposed. They include:
• Workers in plants where dyes are manufactured
• Manufacturing workers who use it in the production of polymers
• Workers who use it to make pesticides
• Pharmaceutical manufacturing workers in production plants
• Workers who use it to separate ores
• Welders who use it to clean with chlorinated solvents

To protect workers, the Occupational Safety and Health Administration (OSHA) has set a Permissible Exposure Limit (PEL) for phosgene and NIOSH has a Recommended Exposure Limit (REL).

These are just a few things to know phosgene and potential occupational exposure risks. To learn more about this or other industrial hygiene, environmental, health or safety issues, please visit the websites shown below.

Clark Seif Clark https://www.csceng.com
EMSL Analytical, Inc. https://www.emsl.com
LA Testing https://www.latesting.com
Zimmetry Environmental https://www.zimmetry.com
Healthy Indoors Magazine https://www.healthyindoors.com