Description

Diazinon does not occur naturally in the environment.

The pure chemical is an oil that is colorless and practically odorless. Commercial diazinon is a pale to dark brown liquid.

Uses

• Pesticide uses

Diazinon is the common name of an organophosphorus insecticide used to control pest insects in soil, on ornamental plants, and on fruit and vegetable field crops.

Diazinon is sold under common trade names including Alfatox, Basudin, AG 500, Dazzel, Gardentox, and Knoxout.

Sources

Diazinon may enter the environment from agricultural and household application of the chemical to control insects.

After diazinon has been applied, it may be present in the soil, surface waters (such as rivers and ponds), and on the surface of plants.

How diazinon breaks down

• Air

Diazinon is rapidly broken down to a number of different compounds.

• Water and soil

Diazinon is quickly broken down in a few hours to 2 weeks.

• Plants and animals

Diazinon is rapidly broken down by most animals that eat it and is not likely to build up to high or dangerous levels in animals or plants that you might eat.

Food-primary source of exposure

Small amounts of diazinon have been detected in foods sold to consumers, but studies by the U.S. Food and Drug Administration (FDA) have found that the levels in food are far below the level that might cause any harmful health effects.

Air

You may be exposed to diazinon in air in agricultural areas where diazinon is extensively used or in urban areas where it is applied to lawns and gardens.

Drinking water

You may be exposed to diazinon by drinking contaminated water.

Recently sprayed plants

You may be exposed to diazinon by touching diazinon-treated plant materials such as grass clippings.

Workplace

People who work in the manufacture and professional application of diazinon have the most significant exposure to this insecticide.

Consumer products

Although diazinon was formerly used as the active ingredient in home and garden pest control products, sale of these home and garden products in the United States was stopped in 2004. However, previously purchased diazinon-containing home and garden products may still be in use and present the potential for exposure.

Enter your body

• Inhalation

If you breathe air containing diazinon, you may absorb it into your body through your lungs.

• Ingestion

Diazinon in food or water may also rapidly enter your body through the digestive tract.

• Dermal Contact

Diazinon may enter your body across the skin.

Leave your body

Once in the body, diazinon is rapidly broken down and eliminated from the body mainly in the urine. Diazinon has not been shown to accumulate in any tissues and most of the chemical is eliminated from the body within 12 days.

Human exposure

• High exposure

Short exposures to high levels of diazinon can affect the nervous system. Symptoms include:

• headache, dizziness, weakness
• feelings of anxiety
• constriction of the pupils of the eye
• not being able to see clearly

• Very high exposure

Exposures to very high levels can cause more severe symptoms including:

• nausea, vomiting, abdominal cramps, and diarrhea
• slow pulse
• pinpoint pupils
• difficulty breathing
• passing out (coma)

Long-term exposure to low levels

There is no evidence that long-term exposure to low levels of diazinon causes any harmful health effects in people.

Cancer

Diazinon has not been shown to cause cancer in people or animals. The International Agency for Research on Cancer (IARC) has not classified diazinon for carcinogenicity. EPA classified diazinon as a Group E chemical (evidence of noncarcinogenicity for humans).

Effects in children

It is likely that children would have the same health effects as adults. We do not know whether children would be more sensitive than adults to the effects of diazinon.

One study found neurological and bone effects in young children living in a house were diazinon was misused to control a flea infestation.

Birth defects

There is no evidence that environmental exposure to diazinon causes birth defects or other developmental effects in people.

In animals, levels of exposure to diazinon high enough to affect the health of pregnant mothers caused developmental effects in their newborn babies.

Breast milk

Animal studies have shown that diazinon and/or its breakdown products can be transferred from a pregnant mother to a developing fetus, but no human data were located regarding the transfer of diazinon from the mother to the fetus or nursing infant.

Cautions for those who live in agricultural areas

People who live near agricultural areas where diazinon is still used should stay away from the area that has been treated. Diazinon can be dispersed some distance from a spray zone by air currents and runoff water.

If you are aware that diazinon is being sprayed in the vicinity, you may want to go indoors or leave the area for a short time.

Agricultural workers who have come into contact with relatively large amounts of diazinon at work may need to remove and wash contaminated clothing before coming into contact with other family members.

Wash fruits and vegetables

To reduce the risk of exposure to diazinon residue on fresh fruits or vegetables, wash the foods prior to eating them.

Properly use insect sprays

Occasionally, diazinon may be improperly sprayed inside the home to kill insects. Make sure that any person who treats your home with pesticides is properly certified. Ask what chemical or chemicals are being used. Diazinon is a “restricted use” chemical and is no longer registered for residential indoor or garden use.

Measuring effects

Most of the signs and symptoms resulting from diazinon poisoning are due to the inhibition of an enzyme called acetylcholinesterase in the nervous system. This enzyme is also found in your red blood cells and a similar enzyme (plasma cholinesterase) is found in blood plasma. The most common test for exposure to many organophosphorus insecticides, including diazinon, is to determine the level of cholinesterase activity in the red blood cells or plasma.

It takes time for this enzyme to completely recover to normal levels following exposure. Therefore, a valid test may be conducted a number of days following the suspected exposure. This test indicates only exposure to an insecticide of this type. It does not specifically show exposure to diazinon.

Detecting exposure

Specific tests are available to determine the presence of diazinon or its breakdown products in blood, body tissue, and urine. These tests are only useful if done within a few hours or days of exposure. This is because diazinon is rapidly broken down and excreted from the body.

Drinking water

The EPA has determined that exposure to diazinon in drinking water at a concentration of 20 micrograms per liter (μg/L) for up to 10 days is not expected to cause any harmful effects in a child.

The EPA has determined that lifetime exposure to 1 μg/L diazinon in drinking water is not expected to cause any harmful effects.

Food

The EPA has also set tolerances for residues of diazinon in various raw food products of 0.1–40 parts of diazinon per million parts of food (ppm).