1,3-Dichloropropene is a manufactured chemical that does not occur naturally in the environment. It is a colorless liquid with a sweet smell. There are two forms of 1,3-dichloropropene: cis-1,3-dichloropropene and trans-1,3-dichloropropene. These forms are very similar to each other and are usually combined in different amounts to form mixtures. It is used mainly in farming to kill nematodes, which are pests that eat the roots of crops. It is often sprayed undiluted directly on the soils of vegetable and tobacco crops. Much smaller amounts are used to dissolve or to make other chemicals.



Structural diagrams: National Institutes of Health

Fate & Transport

1,3-Dichloropropene rapidly evaporates from water and soil into the air where it is broken down by sunlight. It dissolves in water and breaks down slowly in water. It may travel deeper into the ground and reach underground water supplies; however, in states where it is often used, very little has been found in the groundwater. When in soil, it is likely to be broken down by small organisms. Other chemicals often found in hazardous waste sites may slow the breakdown of 1,3-dichloropropene. We do not know if 1,3-dichloropropene accumulates in fish. Studies with animals show that most of it leaves the body within 2 days.

Exposure Pathways

Breathing contaminated air or touching it during its use to treat farm crops

Breathing contaminated workplace air or air around hazardous waste sites that contain it

Drinking contaminated water near where it's produced or used, or near hazardous waste sites that contain it.

Health Effects

Most of the adverse health effects from 1,3-dichloropropene come from breathing or touching it when it's produced or used on farm crops. Workers who breathed high levels of 1,3-dichloropropene had irritated skin, eyes, nose, and throat, and coughing, nausea, headache, and fatigue. Short-term high level and long-term lower level studies in animals also show damage to the nose and lung tissues.

The effects from ingesting 1,3-dichloropropene are not known. Animal studies have reported damage to the stomach lining, lung congestion, difficulty walking, and effects on the liver and kidneys from ingesting high levels.

The skin of some workers who made a pesticide that contained 1,3-dichloropropene became sensitive to further exposure. When 1,3-dichloropropene was applied to the skin of animals, irritation of the skin, hair loss, and bleeding from the lungs and stomach occurred.

The Department of Health and Human Services has determined that 1,3-dichloropropene may reasonably be anticipated to be a carcinogen. Studies in animals show an increase in tumors of the stomach, urinary bladder, and lungs from ingestion of 1,3-dichloropropene. Studies in people suggest that 1,3-dichloropropene may be carcinogenic, but no definite conclusion can be made.

Tests are available to measure the amount of 1,3-dichloropropene or its breakdown products in blood and urine. However, the presence of 1,3-dichloropropene or its breakdown products could also mean that you were exposed to some other chemical that breaks down into 1,3-dichloropropene. These tests are only accurate for recent exposures, because 1,3-dichloropropene leaves the body within 1 to 2 days. These tests can't determine if adverse health effects will occur from exposure to 1,3-dichloropropene.

Information excerpted from:

Toxicological Profile for 1,3-Dichloropropene

Agency for Toxic Substances and Disease Registry
U.S. Dept. of Health and Human Services