Cypermethrin シペルメトリン
Pyrethroids: Developed from a component of pyrethrum flowers (pyrethrin). They act on the sodium channels of nerves.
In Japan
- Registration
- Registered as a pesticide (first registered October 28, 1986). 8 formulated products contain it.
- Main registered crops
- onion, citrus, lettuce, non-heading lettuce (leaf lettuce), bell pepper, cucumber and others (87 crop names in the registered uses)
- Toxicity class
- Active ingredient: Deleterious substanceClasses of the 8 formulated products (diluted products sold): deleterious substance 8Classes under Japan's Poisonous and Deleterious Substances Control Act.
- ADI (acceptable daily intake)
- 0.022 mg per kg of body weight per day
- ARfD (acute reference dose)
- 0.04 mg per kg of body weight
- Evaluation
- Food Safety Commission of Japan, March 27, 2018
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 |
|---|---|---|---|
| DomesticNo. 11 by detection rate | 100 / 3,537 | 2.8% | 0 |
| Imported | 125 / 4,573 | 2.7% | 0 |
Found in domestic foods: edamame, persimmon, kabocha pumpkin (including squash), komatsuna (Japanese mustard spinach), nira (garlic chives), grape, spinach, peach, apple, bok choy (chingensai), tomato, melons (fruit) and others (max. 0.47 ppm)
Found in imported foods: cherry (including cherries), other citrus fruits, other nightshade (Solanaceae) vegetables, other herbs, other vegetables, corn (maize), nira (garlic chives), Welsh onion (including leek), asparagus, okra, orange (including navel orange), grapefruit and others (max. 0.7 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 c250 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
- Approved in the EU (approval expires January 2029)Designated a “candidate for substitution” (to be replaced if safer alternatives exist).EU ADI: 0.005 mg/kg bw/day; ARfD: 0.005 mg/kg bw
- IARC (carcinogenicity)
- No matching entry in the IARC list (not evaluated or out of scope, including Group 3)
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 Cypermethrin (March 27, 2018) (Japanese)
- MHLW, results of pesticide residue testing in foods, fiscal 2024 (Japanese)
- WHO Recommended Classification of Pesticides by Hazard 2019
- EU Pesticides Database (Cypermethrin)
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.