Diazinon ダイアジノン
Organophosphates: Block the action of the enzyme that stops nerve signals (acetylcholinesterase). Used for a long time.
In Japan
- Registration
- Registered as a pesticide (first registered April 22, 1955). 28 formulated products contain it.
- Main registered crops
- cabbage, broccoli, cauliflower, Welsh onion, onion, watermelon and others (101 crop names in the registered uses)
- Toxicity class
- Active ingredient: Deleterious (ordinary at 5% or less, and for 30% microcapsule formulations)Classes of the 28 formulated products (diluted products sold): deleterious substance 14, ordinary substance 14Classes under Japan's Poisonous and Deleterious Substances Control Act.
- ADI (acceptable daily intake)
- 0.001 mg per kg of body weight per day
- ARfD (acute reference dose)
- 0.025 mg per kg of body weight
- Evaluation
- Food Safety Commission of Japan, December 12, 2017
ADI: the amount considered to have no effect on health even if eaten every day for a lifetime. ARfD: the amount considered to have no effect on health when eaten at one time (within 24 hours). Both are set by the Food Safety Commission of Japan, mainly from animal studies.
In Japan's national residue testing (fiscal 2024)
| Produce | Detected / tested | Detection rate | Over the limit |
|---|---|---|---|
| Domestic | 9 / 5,076 | 0.2% | 0 |
| Imported | 2 / 2,642 | 0.1% | 0 |
Found in domestic foods: komatsuna (Japanese mustard spinach), carrot, spinach, peach, apple, Japanese pear (max. 0.06 ppm)
Found in imported foods: pineapple, lemon (max. 0.007 ppm)
Tests are counted as pesticide × sample. Any detection counts as “detected” — it does not mean the limit was exceeded. For pesticides outside the top 20, figures are summed from the food-by-food tables of the full report.
Evaluations abroad
- WHO acute toxicity class
- II (Moderately hazardous), LD50 300 mg/kgBased on the toxicity of the undiluted active ingredient given once, mainly to rats by mouth (LD50 = the dose that kills half; the smaller, the stronger the acute toxicity). It is not an assessment of the safety of residues in food.
- EU
- Not approved in the EUEU ADI: 0.0002 mg/kg bw/day; ARfD: 0.025 mg/kg bw
- IARC (carcinogenicity)
- Group 2A (probably carcinogenic to humans)Diazinon: Vol. 112 (evaluated 2015)IARC classifications rate the strength of evidence that something can cause cancer, not the size of the risk at the amounts eaten in food.
Good to know
- In the United States, more than 50 incidents of birds dying from its use on golf courses and lawns were reported, and in 1988 the EPA canceled its use on golf courses and sod farms.
Related explainers
Sources
- FAMIC (Food and Agricultural Materials Inspection Center), pesticide registration information (as of Sept. 30, 2026) (Japanese)
- Food Safety Commission of Japan, risk assessment report on Diazinon (December 12, 2017) (Japanese)
- MHLW, results of pesticide residue testing in foods, fiscal 2024 (Japanese)
- WHO Recommended Classification of Pesticides by Hazard 2019
- EU Pesticides Database (Diazinon)
- IARC (International Agency for Research on Cancer) List of Classifications
Last checked 2026-10-01. Registrations and evaluations change over time. This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.