1,3-Dichloropropene, sold under diverse trade names, is an organochlorine compound with the formula C3H4Cl2. It is a colorless liquid with a sweet smell. It is feebly soluble in water and evaporates easily. It is used mainly in farming as a pesticide, specifically as a preplant fumigant and nematicide. It acts non-specifically and is in IRAC class 8A. It is widely used in the US and other countries, but is banned in 34 countries (including the European Union).[4]
It is usually obtained as a mixture of the geometric isomers, called (Z)-1,3-dichloropropene, and (E)-1,3-dichloropropene. Although it was first applied in agriculture in the 1950s, at least two biodegradation pathways have evolved. One pathway degrades the chlorocarbon to acetaldehyde via chloroacrylic acid.[6]
Safety
The TLV-TWA for 1,3-dichloropropene (DCP) is 1 ppm.[7] It is a contact irritant. A wide range of complications have been reported.[8]
Carcinogenicity
Evidence for the carcinogenicity of 1,3-dichloropropene in humans is inadequate, but results from several cancer bioassays provide adequate evidence of carcinogenicity in animals. In the US, the Department of Health and Human Services (DHHS) has determined that 1,3-dichloropropene may reasonably be anticipated to be a carcinogen. In California, the Office of Environmental Health Hazard Assessment has determined that 1,3-dichloropropene is a carcinogen, and in 2022 established a No Significant Risk Level (NSRL) of 3.7 micrograms/day.[9] 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.[8]
Use
1,3-Dichloropropene is used as a pesticide in the following crops:[10]
1,3-Dichloropropene Use in Crops
Crop
Pounds (lb)
Primary Pesticide?
Tobacco
12,114,887
Yes
Potatoes
12,044,736
Yes
Sugar Beets
5,799,613
Yes
Cotton
3,735,543
Yes
Peanuts
3,463,003
Yes
Sweet Potatoes
1,210,872
Yes
Onions
674,183
Yes
Carrots
531,752
Yes
Watermelons
133,801
No
Cantaloups
121,395
No
Cucumbers
76,735
No
Strawberries
71,753
No
Sweet Peppers
28,247
No
Melons
12,471
No
Blueberries
3,090
No
Asparagus
1,105
No
Contamination
The ATSDR has extensive contamination information available.[11]
Market history
Under the brand name Telone, 1,3-D was one of Dow AgroSciences's products until the merger into DowDuPont. Then it was spun off with Corteva, and as of 2020[update] has been licensed to Telos Ag Solutions and is no longer a Corteva product.[1][2]