2,4-D 2,4-D

In Japan

Registration

Registered as a pesticide (first registered March 16, 1951). 9 formulated products contain it.

Main registered crops

trees and similar, paddy field crops, paddy field crops, upland crops, turfgrass, paddy rice, sugarcane and others (9 crop names in the registered uses)

Toxicity class

Active ingredient: 2,4-PA isopropylamine salt: Ordinary / 2,4-PA dimethylamine: Ordinary

Classes of the 9 formulated products (diluted products sold): ordinary substance 9

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

ADI (acceptable daily intake)

0.0099 mg per kg of body weight per day

ARfD (acute reference dose)

0.15 mg per kg of body weight

Evaluation

Food Safety Commission of Japan, May 16, 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)

Found in imported foods: cherry (including cherries), walnut, sesame seeds, other citrus fruits, other fruits, almond, orange (including navel orange), cacao beans, grapefruit, coffee beans, lemon, adzuki-type beans and others (max. 0.53 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 375 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

Approved in the EU (approval expires December 2030)

EU ADI: 0.02 mg/kg bw/day; ARfD: 0.3 mg/kg bw

IARC (carcinogenicity)

Group 2B (possibly carcinogenic to humans)

2,4-D (2,4-dichlorophenoxyacetic acid) (See also Chlorophenoxy herbicides): Vol. 113 (evaluated 2015) / Chlorophenoxy herbicides: Vol. 41, Suppl. 7 (evaluated 1987)

IARC classifications rate the strength of evidence that something can cause cancer, not the size of the risk at the amounts eaten in food.

Related explainers

• Most and least toxic pesticides, ranked (acute toxicity, ADI, carcinogenicity)
• Does washing, peeling or boiling remove pesticide residues? Measured results
• 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 2,4-D (May 16, 2017) (Japanese)
• MHLW, results of pesticide residue testing in foods, fiscal 2024 (Japanese)
• WHO Recommended Classification of Pesticides by Hazard 2019
• EU Pesticides Database (2,4-D)
• 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.

Other Hormone-type (2,4-D, MCPA and others)

• MCPA
• Dicamba
• Triclopyr