Atmosphere

Air toxics and indoor air quality in Australia

State of knowledge report
Environment Australia, 2001
ISBN 0 6425 4739 4

Part C: Factsheets (continued)

1,3-Butadiene (vinyl ethylene)

Substance name: 1,3-Butadiene (vinyl ethylene)
CASR number: 106-99-0
Molecular formula: C4H6
Synonyms: Butadiene, vinyl ethylene, biethylene, pyrroline, buta-1,3-diene, bivinyl, alpha-gamma-butadiene, erythrene, divinyl, trans-butadiene, buta-1,3-dieen

Physical and chemical properties

1,3-Butadiene is a colourless gas with a mild aroma like petrol. It is not soluble in water, but is soluble in most organic solvents.

Melting point: -108.9°C
Boiling point: -4.4°C
Vapour density: 0.188

Noncorrosive, explosive, flammable.

Common uses

1,3-Butadiene is a chemical made from the processing of petroleum. Most of the 1,3-butadiene manufactured is used in the production of synthetic rubber. It is also used in the production of plastics and acrylics. These synthetic materials are used to manufacture automotive tyres and tyre products, automotive hoses, belts, seals, and gaskets. 1,3-Butadiene is also used as a chemical intermediate in the production of some fungicides, and in the manufacture of latex adhesives, nylon carpet backing, paper coatings, pipes, conduits, electrical components and luggage. Small levels of 1,3-butadiene are found in petrol.

Sources of emissions

Point sources

The primary stationary sources of 1,3-butadiene are petroleum refining, manufacturing of synthetic materials and oil and gas extraction. These all emit to air.

Diffuse sources, and point sources included in aggregated emissions data

Smoking tobacco, agricultural burning, bush and forest fires result in emissions to air.

Natural sources

1,3-Butadiene is emitted to air as a product of incomplete combustion in bush or forest fires, and the burning of biomass (wood, leaves, agricultural burning), including tobacco leaves.

Mobile sources

Motor vehicles emit 1,3-butadiene to air.

Consumer products that may contain 1,3-butadiene

In almost all consumer products produced using 1,3-butadiene, it has been reacted and is no longer available as 1,3-butadiene. However, the burning of many consumer products releases 1,3-butadiene. The burning of petrol (when driving motor vehicles), leaves, or tobacco releases 1,3-butadiene to air.

Health effects

How might I be exposed to 1,3-butadiene?

Workers in the industries that use or produce 1,3-butadiene are at risk of exposure. Smokers are most likely to be exposed through tobacco smoke. Nonsmokers are most likely to be exposed when using consumer products containing 1,3-butadiene, especially if ventilation is poor. The next most significant route of exposure to 1,3-butadiene for most members of the general public is through breathing air in and around heavy traffic areas. People may also be exposed to 1,3-butadiene by exposure to air from production and processing facilities using 1,3-butadiene.

By what pathways might 1,3-butadiene enter my body?

1,3-Butadiene will enter the body if we breathe in contaminated air.

Health guidelines

National Occupational Health and Safety Commission (NOHSC):

What effect might 1,3-butadiene have on my health?

Exposure to the gas can irritate the eyes, nose and throat. Breathing very high levels of 1,3-butadiene for a short time can cause central nervous system damage, blurred vision, nausea, fatigue, headache, decreased pulse rate and pressure and unconsciousness. Long-term exposures at lower levels have shown increases in heart and lung damage.

The International Agency for Research on Cancer classifies 1,3-butadiene as a 'probable human carcinogen'. It is classified by the NOHSC as a Category 2 carcinogen (substance which should be regarded as if it is carcinogenic to humans).

Environmental effects

Environmental fate

1,3-Butadiene quickly evaporates to a gas if released as a liquid. It then decomposes quickly in air in sunlight. In sunlight almost all should be broken down in about one day. When it is not sunny it may take as long as a few weeks to break down.

Environmental transport

Industrial emissions of 1,3-butadiene can produce elevated, but still low-level, concentrations in the atmosphere around the source. Motor vehicles may also produce elevated levels of 1,3-butadiene in areas of higher traffic. Tobacco smoke is the primary source of 1,3-butadiene indoors; because of its short life expectancy in the atmosphere, 1,3-butadiene is expected to be confined to the local area in which it is emitted.

Environmental guidelines

There are no national guidelines.

What effect might 1,3-butadiene have on the environment?

1,3-Butadiene is moderately toxic to aquatic life in the short term and slightly toxic in the long term. There is not enough information to predict additional short or long-term effects of 1,3-butadiene on plants, birds, or other animals. 1,3-Butadiene is not expected to accumulate in fish. Animal studies have reported development effects such as skeletal abnormalities and decreased foetal weights, and reproductive effects, including an increased incidence of shrinkage of the ovaries and testicles. Animal studies have also reported tumours at a variety of sites from inhalation of 1,3-butadiene.

Key

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