1,3-Butadiene is a non-corrosive colourless gas with an odour similar to that of gasoline. 1,3-Butadiene is emitted as a by-product of incomplete combustion of organic matter, as well as being produced commercially for use in the chemical polymer industry (3). It may also be referred to as butadiene or vinylethylene. There are numerous other synonyms and product names; see HSDB for more information.
1,3-Butadiene has been classified by IARC as Group 1, carcinogenic to humans, with sufficient evidence of carcinogenicity in humans. A forthcoming IARC monograph confirms this classification,[28,29] with evidence of leukemia and cancer of the haemolymphatic organs.
Although concurrent exposure to other chemicals complicates analysis of additional adverse health effects, cardiovascular and respiratory effects have been reported. Low levels of exposure may result in sensory irritation while short term high levels may damage the central nervous system. Dermal exposure to liquid 1,3-butadiene can cause irritation and frostbite. Animal data indicates potential for reproductive effects, although there is as yet no evidence in humans
1,3-Butadiene is used primarily in the manufacture of synthetic elastomers, including polybutadiene rubber, used for automobile tires, vehicle parts, and appliance and electrical equipment components; styrene-butadiene rubber (SBR), used in rubber products and chewing gum; styrene-butadiene (SB) latex, used in coated paper, certain types of flooring, adhesives, and tire cord latex; and nitrile-butadiene rubber (NBR), a copolymer of butadiene and acrylonitrile, used for products requiring oil resistance such as hoses and belting.
Polybutadiene is the largest end use of butadiene elastomers in Canada. Production of ABS polymers in Canada ceased in 1994.
Other uses include neoprene rubber, acrylonitrile-butadiene-styrene (ABS) resins, co-polymer resins and latexes for paints, coatings and adhesives, oil lubricant additives, and for rocket propellants. A non-polymer use is for the production of adiponitrile, a nylon intermediate.
1,3-Butadiene has also been used in the production of the agricultural fungicides Captan and Captafol.
Canadian Production and Trade
There is one manufacturer of 1,3-butadiene in Canada. They are located in Sarnia, Ontario.
Styrene-butadiene latex is produced in a plant located in Varennes, Quebec, and while there was a nitrile-butadiene plant located in Sarnia, it was recently closed.
Butadiene is an important chemical worldwide. An estimated 9.3 million tonnes were produced in 2005.
Production and Trade
Export: Solely to US
130,136 t of 'buta-1,3-diene and isoprene'
Import: Mainly from US
7,093 t of 'buta-1,3-diene and isoprene'
t = tonne kt = kilotonne
Inhalation is the most important route of occupational exposure. Exposure to 1,3-butadiene occurs during its production, the production of butadiene-based polymers, and in petroleum refining, since butadiene occurs naturally in petroleum products and as a combustion product.
Facilities manufacturing finished rubber and plastic products typically do not have concentrations of 1,3-butadiene above the detection limit.
The most important route of exposure for the general Canadian population is inhalation.
Factors contributing to indoor levels of butadiene include cigarette smoke, proximity to vehicle exhaust source (traffic or garage), cooking activity involving heated fats and oils (Chinese rapeseed, peanut, soybean and canola oils), wood burning and natural gas/oil space heating.
Factors contributing to levels in outdoor air include forest fires, vehicle emissions, aircraft, marine and rail transportation, waste incinerator emissions, and thermal breakdown of butadiene-based rubbers and plastics.[2,3] Newer vehicles with catalytic converters emit less 1,3-butadiene than older vehicles.
Butadiene is not persistent in air and has an atmospheric half life of a few hours, depending on weather conditions. 1,3-Butadiene levels in ambient air have been measured at several sites across Canada since 1987. Data published in 2006 relates:
That the average 1,3-butadiene concentration at urban sites from 2000-2003 was 0.22 μg/m3. The average rural concentration was 0.02 µg/m3.
That the highest 24 hour concentration was 2.58 μg/m3, measured in Sarnia (near an industrial point source), in 2001.
That other industrial point sources include Yellowknife, Fort McMurray, Port Mellon, Montreal/Varennes and Oakville.
That industrial emissions have declined since 2004.
There is currently little available data concerning the presence of butadiene in drinking-water, food and soil in Canada. The potential for butadiene to migrate to food from containers exists, but is expected to be minimal; this route of exposure is likely much less important than inhalation.
Searches of environmental and consumer product databases yielded the following results on current potential for exposure to 1,3-butadiene in Canada:
NPRI and US Household Products Database
Search term: '1,3-butadiene'
Released into Environment
Petroleum refineries, chemical manufacture, and one diamond mine
J. Graff, N. Sathiakumar, M. Macaluso, G. Maldonado, R. Matthews, E. Delzell, (2005). 'Chemical exposures in the synthetic rubber industry and lymphohematopoietic cancer mortality,' Journal of Environmental and Occupational Medicine. Vol. 47, pp. 916–932.
Curren, K., et al (2006), 'Ambient air 1,3-butadiene concentrations in Canada (1995-2003) : seasonal, day of week variations, trends, and source influences,' Atmospheric environment, Vol. 40, no. 1, pp. 170-181
N. Sathiakumar, J. Graff, M. Macaluso, G. Maldonado, R. Matthews, E. Delzell, (2005). 'An updated study of mortality among North American synthetic rubber industry workers,' Occupational and Environmental Medicine. Vol. 62, pp. 822–829.
Hughes, K., et al (2003), '1,3-Butadiene: Exposure Estimation, Hazard Characterization, and Exposure- Response Analysis,' Journal of Toxicology and Environmental Health Part B: Critical Reviews, Vol. 6, No. 1, pp. 55-83