Olefins like ethylene, propylene and butadiene are building block chemicals used to manufacture other chemicals that help make a range of consumer and industrial products. Because these chemicals are reacted in the manufacturing process, exposure to the monomer forms of these olefins in consumer products is generally low.
At sufficiently high concentrations, ethylene is a highly flammable volatile gas. Ethylene can be easily ignited, and containers holding this chemical may rupture if exposed to fire or intense heat for a prolonged period.
A large proportion of ethylene in urban air is due to automobile emissions. Industrial contributions of ambient ethylene are mainly due to emissions from stacks, flares and leaks in pipe fittings. Ethylene may also be released naturally into air by microbes, plants and mammals. Laboratory animal studies indicate ethylene to be relatively non-toxic. However, at high concentrations, ethylene can lower oxygen concentrations and act as an asphyxiant.
Propylene is extremely flammable and is classified as an extremely flammable gas by the Globally Harmonized System of Classification and Labeling of Chemicals. Propylene gas can cause asphyxiation, and in its liquid form can cause frostbite if it comes into contact with skin. ACGIH has established a TLV for propylene of 500 ppm averaged for worker exposure over an 8-hour period.
Labeling process containers and providing employees that interact with propylene in workplace settings with hazard training is also essential. Additional safety practices to help protect workers from exposure to propylene include wearing the following personal protective equipment:
- Gloves and clothing made of material that cannot be permeated by the chemical such as neoprene;
- Non-vented, impact resistant goggles or face shields; and
- Air respirators approved by the National Institute for Occupational Safety and Health (NIOSH).
Inhalation is the primary route of 1,3-butadiene exposure and mainly occurs in workplace settings in industries such as rubber and latex production, petroleum refining and water treatment.
In terms of consumer exposure, while tires and crumbled rubber containing 1,3-butadiene can be used to make playground surfaces, a report from EPA shows that exposure to 1,3-butadiene through this application is limited. Consumer exposure to 1,3-butadiene at high concentrations is rare and can be further reduced by avoiding tobacco smoke.