Acrolein

107-02-8

Hazard Summary-Created in April 1992; Revised in January 2000

Acrolein is primarily used as an intermediate in the manufacture of acrylic acid. It can be formed from the breakdown of certain pollutants in outdoor air or from burning tobacco or gasoline. It is extremely toxic to humans from inhalation and dermal exposure. Acute (short-term) inhalation exposure may result in upper respiratory tract irritation and congestion. No information is available on its reproductive, developmental, or carcinogenic effects in humans. The animal cancer data are limited, with one study reporting an increased incidence of adrenocortical tumors in rats exposed to acrolein in the drinking water. EPA considers acrolein data are inadequate for an assessment of human carcinogenic potential.

Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS), which contains information on inhalation chronic toxicity of acrolein and the RfC, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Acrolein.

Uses

The largest use for acrolein is as an intermediate in the manufacture of acrylic acid (1)

Sources and Potential Exposure

Acrolein can be formed from the breakdown of certain pollutants found in outdoor air, from burning tobacco, or from burning gasoline. (1)
Airborne exposure to acrolein may occur from breathing contaminated air, from smoking tobacco or proximity to someone who is smoking, or from being near automobiles or oil or coal power plants. In several large cities, acrolein has been measured at 9 parts per billion (ppb). (1)
Occupational exposure to acrolein could occur in industries that use acrolein to make other chemicals. (1)
Small amounts of acrolein may be found in some foods, such as fried foods, cooking oils, and roasted coffee. (1)
Acrolein has not been detected in drinking water, and is not commonly found in surface water. (1)

Assessing Personal Exposure

There are currently no tests available to determine personal exposure to acrolein. (1)

Health Hazard Information

Acute Effects:

Acute inhalation exposure to high levels (10 parts per million [ppm]) of acrolein in humans may result in death. Effects on the lung, such as upper respiratory tract irritation and congestion have been noted at acrolein levels ranging from 0.17 ppm to 0.43 ppm. (1-3)
Acrolein is considered to have high acute toxicity, based on short-term animal tests in rats. (1,4)

Chronic Effects (Noncancer):

The major effects from chronic (long-term) inhalation exposure to acrolein in humans consist of general respiratory congestion and eye, nose, and throat irritation. (1,2,5)
Acrolein is a strong dermal irritant, causing skin burns in humans. (1,2,5)
Animal studies have reported that the respiratory system is the major target organ for acrolein toxicity. (1,2,5)
The Reference Concentration (RfC) for acrolein is 0.00002 milligrams per cubic meter (mg/m³) based on squamous metaplasia and neutrophilic infiltration of nasal epithelium in rats. The RfC is an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious noncancer effects during a lifetime. It is not a direct estimator of risk but rather a reference point to gauge the potential effects. At exposures increasingly greater than the RfC, the potential for adverse health effects increases. Lifetime exposure above the RfC does not imply that an adverse health effect would necessarily occur. (3)
EPA has high confidence in the studies on which the RfC was based because adequate numbers of animals were used, careful attention was paid to experimental protocol, and together they demonstrated a consistent profile of histopathological changes in the respiratory system; low to medium confidence in the database due to the lack of chronic data and adequately conducted reproductive or developmental studies; and, consequently, medium confidence in the RfC.
EPA has not established a Reference Dose (RfD) for acrolein. (3)
EPA has calculated a provisional RfD of 0.02 milligrams per kilogram body weight per day (mg/kg/d) for acrolein. The provisional RfD is a value that has had some form of Agency review, but it does not appear on IRIS. (6)

Reproductive/Developmental Effects:

No information is available on the reproductive or developmental effects of acrolein in humans. (1)
In the one available reproductive animal study, rats were exposed to acrolein by inhalation, with no effects observed on the number of pregnancies or the number and weights of the fetuses. (1)
Acrolein has been reported to cause birth defects in rats when injected directly into the embryonic tissue. (1)

Cancer Risk:

No information is available on the carcinogenic effects of acrolein in humans. (1,3)
Limited animal cancer data are available; one inhalation study in rats reported no evidence of tumors in the respiratory tract or in other tissues and organs, while another study reported an increased incidence of adrenocortical tumors in female rats exposed to acrolein in drinking water. (1,3)
EPA has classified acrolein as data are inadequate for an assessment of human carcinogenic potential based on limited evidence of carcinogenicity in animals, the structural similarity of acrolein to substances possibly carcinogenic to humans, the carcinogenic potential of one of its metabolites, and the lack of human data. (3)

Physical Properties

Acrolein is a water-white or yellow liquid that burns easily and is easily volatilized. (1)
Acrolein has a disagreeable odor and an odor threshold of 0.2 ppm. (1,8)
The chemical formula for acrolein is C₃H₄O and the molecular weight is 56.06 g/mol. (1)
The vapor pressure for acrolein is 220 mm Hg at 20 °C, and its log octanol/water partition coefficient (log K_ow) is -0.01. (1)

Conversion Factors:

To convert concentrations in air (at 25°C) from ppm to mg/m³: mg/m³ = (ppm) × (molecular weight of the compound)/(24.45).

For acrolein: 1 ppm = 2.29 mg/m³.

Health Data from Inhalation Exposure

AIHA ERPG

ACGIH ceiling--

LC₅₀ (Lethal Concentration₅₀)

LOAEL

NIOSH IDLH

NIOSH REL

NIOSH STEL

OSHA PEL

The health and regulatory values cited in this factsheet were obtained in December 1999.
^a Health numbers are toxicological numbers from animal testing or risk assessment values developed by EPA.
^b Regulatory numbers are values that have been incorporated in Government regulations, while advisory numbers are nonregulatory values provided by the Government or other groups as advice. OSHA numbers are regulatory, whereas NIOSH, ACGIH, and AIHA numbers are advisory.
^c This LOAEL is from the critical study used as the basis for the RfC.

References

Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Acrolein. Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA. 1990.
U.S. Department of Health and Human Services. Hazardous Substances Data Bank (HSDB, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.
U.S. Environmental Protection Agency. Integrated Risk Information System (IRIS) on Acrolein. National Center for Environmental Assessment, Office of Research and Development, Washington, D.C. 1999.
U.S. Department of Health and Human Services. Registry of Toxic Effects of Chemical Substances (RTECS). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.
E.J. Calabrese and E.M. Kenyon. Air Toxics and Risk Assessment. Lewis Publishers, Chelsea, MI. 1991.
U.S. Environmental Protection Agency. Health Effects Assessment Summary Tables. FY 1997 Update. Solid Waste and Emergency Response, Office of Emergency and Remedial Response, Cincinnati, OH. EPA/540/R-97-036. 1997.
J.E. Amoore and E. Hautala. Odor as an aid to chemical safety: Odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. Journal of Applied Toxicology, 3(6):272-290. 1983.
American Conference of Governmental Industrial Hygienists (ACGIH). 1999 TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents, Biological Exposure Indices. Cincinnati, OH. 1999.
Occupational Safety and Health Administration (OSHA). Occupational Safety and Health Standards, Toxic and Hazardous Substances. Code of Federal Regulations. 29 CFR 1910.1000. 1998.
National Institute for Occupational Safety and Health (NIOSH). Pocket Guide to Chemical Hazards. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention. Cincinnati, OH. 1997.
American Industrial Hygiene Association (AIHA). The AIHA 1998 Emergency Response Planning Guidelines and Workplace Environmental Exposure Level Guides Handbook 1998.