Triclopyr トリクロピル

In Japan

Registration

Registered as a pesticide (first registered August 5, 1981). 16 formulated products contain it.

Main registered crops

Japanese lawn grass, trees and similar, Japanese cedar, hinoki cypress, forest trees, Chinese fir and others (6 crop names in the registered uses)

Toxicity class

Active ingredient: Triclopyr triethylammonium: Ordinary / Triclopyr butoxyethyl: Ordinary

Classes of the 16 formulated products (diluted products sold): ordinary substance 16

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

ADI (acceptable daily intake)

No risk assessment report by the Food Safety Commission of Japan was found

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 710 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 March 2027)

EU ADI: 0.03 mg/kg bw/day; ARfD: 0.3 mg/kg bw

IARC (carcinogenicity)

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

Related explainers

• Most and least toxic pesticides, ranked (acute toxicity, ADI, carcinogenicity)

Sources

• FAMIC (Food and Agricultural Materials Inspection Center), pesticide registration information (as of Sept. 30, 2026) (Japanese)
• MHLW, results of pesticide residue testing in foods, fiscal 2024 (Japanese)
• WHO Recommended Classification of Pesticides by Hazard 2019
• EU Pesticides Database (Triclopyr)

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)

• 2,4-D
• MCPA
• Dicamba