ToxFAQsTM for Dichloropropenes

CAS#: 26952-23-8

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This fact sheet answers the most frequently asked health questions (FAQs) about dichloropropenes. For more information, call the ATSDR Information Center at 1-800-232-4636. This fact sheet is one in a series of summaries about hazardous substances and their health effects. It is important you understand this information because these substances may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present.


Exposure to 1,3-dichloropropene occurs mainly in farms where it is used to treat crops or in factories where it is made. Exposure to other dichloropropenes is much more limited. Dichloropropenes cause irritation at the point of contact. Ingestion of high amounts of 1,3-dichloroprene can cause severe stomach damage. 1,1-, 1,2-, 1,3-, and 2,3-dichloropropene have been found in at least 2, 9, 107, and 3 of the 1,699 current or former National Priority List sites, respectively, identified by the Environmental Protection Agency (EPA).

What are dichloropropenes?

There are five different types (or isomers) of dichloropropene molecules: 1,1-dichloropropene; 1,2-dichloropropene; 1,3-dichloropropene; 2,3-dichloropropene; and 3,3-dichloropropene.

1,3-Dichloropropene is a colorless liquid with a sweet smell. It is used mainly in farming as a pesticide. Much less is known about the other dichloropropenes. 2,3-Dichloropropene is used in industry to make other chemicals. No uses were found for 1,1-, 1,2-, or 3,3-dichloropropene.

Because 1,3-dichloropropene is produced and used in much higher amounts than the other isomers and because it is released to the environment as a pesticide, most of the data available are for 1,3-dichloropropene. Therefore, the focus of this summary is the 1,3-dichloropropene isomer.

What happens to dichloropropenes when they enter the environment?

  • 1,3-Dichloropropene is quickly broken down in air, usually within several days.
  • Some of the 1,3-dichloropropene in soil and water will evaporate into the air. The rest will be broken down.
  • Other dichloropropene isomers are expected to behave similarly to 1,3-dichloropropene in the environment, but specific information is not available.

How might I be exposed to dichloropropenes?

  • The primary way you can be exposed to 1,3-dichloropropene is by breathing air containing it.
  • Breathing contaminated workplace air or air around hazardous waste sites that contain it.
  • Drinking contaminated water or touching contaminated soil where it is produced or used, or near hazardous waste sites that contain it.
  • 1,1-, 1,2-, 2,3-, and 3,3-dichloropropene are not commonly detected in air, surface water, drinking water, soil, or food.
  • Higher amounts of 2,3-dichloropropene may be released from facilities that produce or use this chemical. Thus, people living near these facilities may be exposed to higher levels of this chemical.

How can dichloropropenes affect my health?

Most of the 1,3- and 2,3-dichloropropene that is inhaled or ingested will rapidly enter the bloodstream.

Rats and mice that inhaled 1,3-dichloropropene or 2,3-dichloropropene repeatedly had damage to the lining of the nose. Damage to the urinary bladder and anemia were also seen in animals inhaling 1,3-dichloropropene for a long time.

Damage to the stomach lining and anemia were seen in animals orally exposed to 1,3-dichloropropene. Skin and eye irritation are seen in animals after 1,3-dichloropropene gets on their skin or in their eyes.

A few workers who had skin contact with pesticides containing 1,3-dichloropropene developed blisters and an allergic reaction on their skin.

How likely are dichloropropenes to cause cancer?

The Department of Health and Human Services (DHHS) has determined that 1,3-dichloropropene may reasonably be anticipated to be a carcinogen. The International Agency for Research on Cancer (IARC) has determined that 1,3-dichloropropene is possibly carcinogenic to humans. The EPA has classified 1,3-dichloropropene as a probable human carcinogen.

How can dichloropropenes affect children?

The effects of dichloropropenes have not been studied in children, but children would likely experience the same effects seen in adults exposed to these chemicals. We do not know whether children differ from adults in their susceptibility to health effects from exposure to dichloropropenes.

We do not know whether dichloropropenes can cause birth defects in humans. Pregnant rats that inhaled 1,3-dichloropropene gave birth to fewer pups or pups with lower body weight. This occurred at exposures high enough to be toxic to the mothers.

How can families reduce the risks of exposure to dichloropropenes?

  • Stay away from agricultural areas that have been treated with dichloropropenes.
  • Workers who handle dichloropropenes should remove contaminated clothing and wash before coming in contact with family members.
  • Children should be encouraged to wash their hands after playing near treated soil and discouraged from putting their hands in their mouths.

Is there a medical test to determine whether I've been exposed to dichloropropenes?

Tests are available that measure 1,3- or 2,3-dichloropropene or their breakdown products in blood and urine. Blood levels of breakdown products from 1,3-dichloropropene could be used to predict how much 1,3-dichloropropene has been breathed. However, tests for 1,3- or 2,3-dichloropropene in the blood and urine would only be useful for recent exposures, because dichloropropenes leave the body within 1 to 2 days. These tests cannot determine whether adverse health effects will occur.

Has the federal government made recommendations to protect human health?

EPA has established a health advisory level for 1,3-dichloropropene of 0.03 milligrams per liter (0.03 mg/L) that should not be exceeded in order to protect children's health.


Agency for Toxic Substances and Disease Registry (ATSDR). 2008. Toxicological Profile for 1,3-Dichloropropene. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

Where can I get more information?

If you have questions or concerns, please contact your community or state health or environmental quality department or:

For more information, contact:
Agency for Toxic Substances and Disease Registry
Office of Innovation and Analytics, Toxicology Section
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO

ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.

Page last reviewed: March 12, 2015