Health Concerns

1,3-Butadiene

The primary way 1,3-butadiene may enter the body is by inhalation of contaminated air into the lungs. Due to a lack of adequate human epidemiologic data with respect to this compound, much of what we know about 1,3-butadiene has been obtained from experimental studies of very high exposures with laboratory animals. Some of the information is helpful in estimating how this chemical may behave in humans. For example, although no studies are currently available as to how much of the 1,3-butadiene vapors inhaled into the lungs by humans is actually absorbed into the blood stream, experimental studies with laboratory animals have noted rapid absorption of such vapors from the lungs into the blood (ATSDR, 1992). Once in the blood stream, the absorbed compound can be distributed throughout the body (whether it be the body of a laboratory animal or a human). Animal studies also indicate that absorbed 1,3-butadiene may be broken down into other compounds (metabolites) which leave the body through the urine and in air exhaled from the lungs (ATSDR, 1992).

It is known that brief inhalation of elevated levels of 1,3-butadiene by humans can irritate the eyes, nose and throat. Such exposures can also damage the central nervous system, cause blurred vision, nausea, fatigue, headache, decreased blood pressure and pulse rate and unconsciousness (ATSDR, 1992). It is believed that inhalation of very high levels of this compound could produce symptoms such as drunkenness, unconsciousness or in very extreme instances, death (ATSDR, 1992). Fortunately, no human exposure to such high levels has been reported to date.

Increased incidence of heart disease, lung disease, blood disease and cancer have been noted in studies of workers who have inhaled low levels of 1,3-butadiene, in a mix of other volatile chemicals, for long periods of time (ATSDR, 1992). Because exposure was to more than one chemical at a time, it is not known which chemical or combination of chemicals may be responsible for the health effects noted.

Dermal contact with 1,3-butadiene can cause skin irritation and frostbite in humans (ATSDR, 1992). No information is available on potential health effects in humans from ingestion of food and/or drink that may contain low levels of 1,3-butadiene.

Experimental studies with laboratory animals exposed to high levels of 1,3-butadiene vapors for even short periods of time has resulted in damage to blood producing organs, nasal tissues and at extreme levels, death. Increased birth defects were noted in pups of laboratory rodents that had been exposed to elevated levels of 1,3-butadiene vapors during pregnancy. Kidney, liver, lung and reproductive organ damage have been noted in lab rodents experimentally exposed to low levels of 1,3-butadiene vapors for long periods of time. Long term exposure to even small amounts of this compound in the air has resulted in cancers in laboratory rodents (ATSDR, 1992). No information is available on potential health effects in laboratory animals from ingestion of food and/or water containing 1,3-butadiene.

1,3-Butadiene has been classified as Class B2: Probable Human Carcinogen by the United States Environmental Protection Agency and as a Group 2A: Probable Human Carcinogen by the International Agency for Research on Cancer.

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Last Updated: 1/31/03