Backyard Neurotoxin On the Way Out
EPA Cites Unacceptable Risk of Diazinon to Consumers

December 11, 2000

The EPA Does It Again

Last summer, the US Environmental Protection Agency (EPA) announced that the pesticide called chlorpyrifos would be banned. On December 5, 2000, the EPA announced that another widely used pesticide called diazinon will also be phased out.

Diazinon: A Popular Backyard Pesticide

Diazinon is used on lawns, around homes and in gardens to kill insects such as chinchbugs, earwigs, aphids, fruitflies, mites, cutworms, crane flies, ants, silverfish, and cockroaches. According to the EPA, over 13 million pounds of diazinon are used each year. About 80% of the pesticide is used on lawns and for residential control of insects. Both chlorpyrifos and diazinon are organophosphate chemicals, known neurotoxins that target and poison the nervous system. Specifically, organophosphates target the acetylcholine neurotransmitter system. One of the major sites of the acetylcholine action is at the neuromuscular junction. The neuromuscular junction is where acetylcholine is released from a neuron and received by muscle cells. An enzyme called acetylcholinesterase (AChE) breaks down acetylcholine into acetate and choline. The action of acetylcholine is therefore stopped by AChE. Organophosphates act by inhibiting AChE. Therefore, in the presence of organophosphate pesticides, acetylcholine levels increase because it is not being broken down. This results in overactivation of the acetylcholine system which may cause symptoms such as nausea, vomiting, muscle weakness, dizziness, and respiratory paralysis in humans. High doses of this poison can even cause death. Many nerve agents (chemical weapons) also cause illness and death by inhibiting acetylcholinesterase.

Mode of Entry

When pesticides are sprayed, tiny chemical droplets are released into the air where they can be breathed in by bugs and humans. These compounds can be also be absorbed by brushing against grass, leaves or other surfaces where the chemicals land. Have you ever had the urge to pluck a ripe peach or apple straight off of a tree and have a bite? Think twice! Remember to wash off any potential pesticide that may still be on your fruit.

The US EPA Action

Because of its potential danger to humans, especially children whose nervous systems are still developing, the EPA will slowly phase out the use of diazinon. A press release issued by the EPA stated that:

  1. For Indoor Household Use:
    • manufacturing of diazinon will stop in March 2001.
    • retail sale of diazinon will stop in December 2002.
  2. For Lawn, Garden and Turf Use:
    • manufacturing of diazinon will stop in June 2003.
    • retail sale of diazinon will stop in August 2003.
  3. For 2002, the manufacturing of diazinon will be reduced by 25%; for 2003, the manufacturing of diazinon will be reduced by 50%.
  4. The use of diazinon on 20 different food crops will begin to stop.

Diazinon in the Garage or Tool Shed?

So, what do you do if you have a bottle or can of diazinon at your house? It is still legal to buy and use diazinon products; just make sure you follow the directions on the label. The EPA recommends other precautions when using diazinon:

  1. Wear gloves, long pants and long-sleeve shirts.
  2. Keep yourself and your pets off the grass for several hours after the pesticide has been applied.
  3. Wash your hands and clothes after using the pesticide.
  4. Prevent the contamination of water (streams, rivers, lakes) to reduce the risk of pesticide exposure to wildlife by disposing of pesticide containers properly.
If you or your family decide to get rid of unused diazinon, contact your state or local hazardous waste disposal program.

References and further information:

  1. US EPA Pesticide Page
  2. Diazinon Summary - US EPA
  3. Nerve Agents - from Neuroscience for Kids

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