Diazinon used to be the most popular lawn and garden pesticide on the market and was commonly used as against ants. About 13 million pounds of diazinon was sold annually, about 80 percent of that for residential use. Between 2000 and 2005, it was taken off the market for consumers and limited only to use by professionals in certain situations.
Diazinon is a liquid, contact insecticide that kills by targeting the nervous system. It is non-systematic, in that it does not move inside a plant after it is absorbed. It is used in agriculture on vegetable, fruit and nut crops to control pests like moths, borers, mites, aphids and scale. While diazinon is still labeled for use against ants, it can only be sold to and used by certified applicators. Diazinon can be used as a barrier spray or to drench nests.
The U.S. Environmental Protection Agency (EPA) announced in 2000 that all residential uses of diazinon would be canceled. Indoor uses were stopped in 2002 and outdoor uses in 2004. As of December 31, 2004, it is illegal to sell diazinon for any outdoor, non-agricultural use. It is not illegal for consumers to use diazinon products they may already own if they follow all label directions and precautions. However, it cannot be used on sod farms or golf courses because of its high toxicity to birds.
Diazinon is extremely poisonous to wildlife. One granule contains enough poison to kill a small bird. In 2005, it was the most commonly found contaminant in the air, rain and water, according to the 2005 "Los Angeles Times" article "EPA Takes Pest Killer Diazinon Off the Shelves." The EPA found it poses a human health risk, especially to children. Although the EPA has classified it as "Class D" or non-carcinogenic, diazinon has been linked to childhood cancers and non-Hodgkin's lymphoma, according to the U.S. Department of Health and Human Services.
While diazinon can be used against ants and will kill ants, there is no reason to use it. Alternative insecticides like pyrethoids, fipronil, chlorfenapyr, and thiamethoxam are just as effective as diazinon and not as toxic to wildlife. These chemicals are available in a variety of different ant killers on the market and will kill ants within a few minutes or a few hours, depending on the type of ant and insecticide.
- National Pesticide Information Center: Diazinon Technical Fact Sheet
- Los Angeles Times; EPA Takes Pest Killer Diazinon Off the Shelves; Marla Cone; January 2005
- University of Wisconsin-Madison Department of Horticulture: Diazinon 5WB
- United States Environmental Protection Agency; Diazinon: Phase Out of all Residential Uses of the Insecticide
- Extension Toxicology Network: Diazinon
- University of Georgia; Applied Ecology and Control of Imported Fire Ants and Argentine Ants; Beverly Anne Wiltz
Darcy Logan has been a full-time writer since 2004. Before writing, she worked for several years as an English and special education teacher. Logan published her first book, "The Secret of Success is Not a Secret," and several education workbooks under the name Darcy Andries. She received her Bachelor of Arts in English and Master of Arts in special education from Middle Tennessee State University.