Olefins - ChemicalSafetyFacts.org


Olefins are a class of chemicals made up of hydrogen and carbon with one or more pairs of carbon atoms linked by a double bond. Ethylene, propylene and 1,3-butadiene are examples of olefins.

Uses & Benefits

Olefins are used as building block materials for many products, including plastics, detergents and adhesives.

Ethylene is the largest volume organic chemical produced globally and a basic building block for the chemistry industry. Ethylene is produced commercially from petroleum and natural gas feedstocks by thermal cracking, a refining process in which heat and pressure are used to break down molecules. Ethylene also occurs naturally in the environment and is produced by plants of all types. Forest fires, cigarette smoke and the incomplete combustion of fossil fuels also create ethylene.

Propylene, also known as propene or methyl ethylene, is a colorless gas with a faint petroleum-like odor. Propylene is primarily used to make polypropylene, a plastic resin used in a variety of consumer product applications including food packaging products and films, squeezable bottles and prescription bottles. Propylene is also an important building block chemical in the production of chemicals like propylene oxide, acrylonitrile, cumene, butraldehyde and acrylic acid. Small amounts of propylene are naturally emitted by plants and when organic matter burns. Cigarette smoke and automobile exhaust also contain propylene.

1,3-Butadiene is a colorless gas with a mild gasoline odor. Many consumer goods and materials, including tires, synthetic turf, carpet backings, gloves and wetsuits, are made from the synthetic elastomers, latexes and plastics produced using styrene-butadiene rubber, polybutadiene rubber and neoprene.

Safety Information

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.  

Ethylene Safety

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 Safety

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).

1,3-Butadiene Safety

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.

Answering Questions

What are olefins?

Olefins are a class of chemicals that include ethylene, propylene, and 1,3-butadiene. They are unsaturated hydrocarbons and contain a double bond between two carbon atoms. Some olefins are used as building block materials for a variety of products, including plastics, detergents and adhesives.

What are some consumer products created from propylene?

Propylene is used to make a plastic resin, polypropylene, that is used in food packaging products and films, squeezable bottles and prescription bottles.

What products are made using 1,3-butadiene?

Synthetic rubber made with 1,3-butadiene is used to make gloves worn to provide protection from chemicals in cleaning products and when working with solvents and oils.  1,3-Butadiene is also used to make wetsuits and synthetic turf.