Use of Diazinon

Diazinon is an organophosphate insecticide used as a means to eliminate cockroaches, ants, silverfish, fleas and other insects in residential buildings and outdoors. Classified as toxicity class II, Diazinon is prohibited on golf courses and certain sod farms due to its toxicity for certain types of animals. The chemical was banned by the Environmental Protection Agency in 2004 for residential use because of its potentially harmful effects on the environment. Professional pest control operators may still use it.


In addition to its uses to control cockroaches and other insects in residential buildings, the chemical is also used to control yellow jackets in the western United States. It is used as a preventative measure against various types of insects on rice, fruit trees, corn, tobacco, potatoes and plants. The chemical also has veterinary uses to prevent animals from fleas and tick. The product is available in a variety of forms, including dust, granules, powder and seed dressings.

Ecological Effects

Diazinon is extremely hazardous to a variety of animals. Birds are especially at risk when ingesting the chemical, most notably Canada geese and mallard ducks. According to the EPA, numerous deaths among birds have occurred as a result of this drug in all parts of the country during each of the four seasons. Diazinon has also proved to be highly toxic to fish and other aquatic animals. While the chemical has been shown to affect all types of fish to some degree, saltwater fish are affected more than freshwater fish.

Environmental Effects

The chemical can also have a negative effect on the environment, most notably in the ground and water. Diazinon has a half-life of two to four weeks in soil and, in some cases, can penetrate through to the top layer of soil, causing possible contamination of groundwater. The pesticide has been found in more than 50 wells in California and in other water sources in Japan and Ottawa. As a result, the EPA was forced to take action to regulate use of the chemical.

EPA Regulation

On December 31, 2004, the Environmental Protection Agency agreed with Diazinon representatives to phase out residential uses of the chemical to prevent further damage to the environment and ecosystem. While the product is no longer sold, it is still legal for those who have already purchased the chemical to continue using the product as needed as long as directions are followed. The chemical is still used by professionals as a means of pest control in extreme situations.


Follow the proper steps when disposing of Diazinon. First, identify a local waste agency by looking in the government section of the phone book. Look for sections such as solid waste, refuse collection, or garbage and trash. Once a listing is found, call and set up an appointment for a waste official to dispose of your pesticide. The chemical should NOT be disposed of through sinks, toilets, storm drains or any other means by which the chemical could penetrate the environment.