Diquat ジクワット

In Japan

Registration

Registered as a pesticide (first registered June 22, 1963). 3 formulated products contain it.

Main registered crops

barley, wheat and other small grains, potato, fruit trees, mulberry, trees and similar, tulip and others (58 crop names in the registered uses)

Toxicity class

Active ingredient: Deleterious substance

Classes of the 3 formulated products (diluted products sold): poisonous substance 2, deleterious substance 1

Classes under Japan's Poisonous and Deleterious Substances Control Act.

ADI (acceptable daily intake)

0.0058 mg per kg of body weight per day

ARfD (acute reference dose)

0.75（ジクワットイオン換算値） mg per kg of body weight

Evaluation

Food Safety Commission of Japan, October 8, 2019

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)

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 231 mg/kg

Based 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 EU (approval ended November 2018)

Designated a “candidate for substitution” (to be replaced if safer alternatives exist).

EU ADI: 0.002 mg/kg bw/day; ARfD: 0.01 mg/kg bw

IARC (carcinogenicity)

No matching entry in the IARC list (not evaluated or out of scope, including Group 3)

Good to know

• The formulated products registered in Japan include a mixture with paraquat (a poisonous substance).

Related explainers

• Most and least toxic pesticides, ranked (acute toxicity, ADI, carcinogenicity)
• How are maximum residue limits set? Japan’s positive list system and how much we actually eat

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 Diquat (October 8, 2019) (Japanese)
• MHLW, results of pesticide residue testing in foods, fiscal 2024 (Japanese)
• WHO Recommended Classification of Pesticides by Hazard 2019
• EU Pesticides Database (Diquat)

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.

Other Bipyridyliums (paraquat, diquat)

• Paraquat