Kasugamycin カスガマイシン

In Japan

Registration

Registered as a pesticide (first registered May 10, 1965). 32 formulated products contain it.

Main registered crops

rice (paddy), onion, daikon radish, cabbage, kiwifruit, nanohana (rape blossoms) and others (47 crop names in the registered uses)

Toxicity class

Active ingredient: Ordinary substance

Classes of the 32 formulated products (diluted products sold): ordinary substance 31, deleterious substance 1

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

ADI (acceptable daily intake)

0.094 mg per kg of body weight per day

ARfD (acute reference dose)

not necessary to set

Evaluation

Food Safety Commission of Japan, May 13, 2026

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.

Evaluations abroad

WHO acute toxicity class

U (Unlikely to present acute hazard in normal use), LD50 >10000 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

IARC (carcinogenicity)

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

Good to know

• A fungicide for rice blast made from an antibiotic produced by actinomycetes found in the soil of Kasuga Taisha Shrine in Nara. One of the pesticides allowed under organic JAS.

Related explainers

• What does “無農薬” (pesticide-free) mean? Why it cannot be labeled, and organic JAS vs. specially cultivated
• 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 Kasugamycin (May 13, 2026) (Japanese)
• WHO Recommended Classification of Pesticides by Hazard 2019
• EU Pesticides Database (Kasugamycin)

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 Fungicides for rice blast and other rice diseases

• Tricyclazole
• Probenazole
• Isoprothiolane
• Pencycuron
• Ferimzone
• Tiadinil
• Validamycin