Copper hydroxide / Copper oxychloride / Copper sulfate / Cuprous oxide 銅剤（塩基性塩化銅・水酸化第二銅など）

In Japan

Registration

Registered as a pesticide (first registered September 27, 1948). 80 formulated products contain it.

Main registered crops

potato, citrus, tomato, onion, cherry tomato, cucumber and others (139 crop names in the registered uses)

Toxicity class

Active ingredient: Copper nonylphenol sulfonate: Ordinary / Basic copper chloride: Ordinary / Basic copper sulfate: Ordinary / Organic copper: Ordinary / Cupric hydroxide: Ordinary / Anhydrous copper sulfate: Deleterious / Copper sulfate: Deleterious

Classes of the 80 formulated products (diluted products sold): ordinary substance 77, deleterious substance 3

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.

Evaluations abroad

WHO acute toxicity class

II (Moderately hazardous), LD50 1000 mg/kg

Copper hydroxide=1000 / Copper oxychloride=1440 / Copper sulfate=300 / Cuprous oxide=470

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 Copper compounds=2029-06-30 / Copper hydroxide=2029-06-30 / Copper oxide=2029-06-30 / Copper oxychloride=2029-06-30 / Tribasic copper sulphate=2029-06-30 / Bordeaux mixture=2029-06-30)

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

EU ADI: Copper compounds=0.07 mg/kg bw/day / Copper oxychloride=Not Applicable / Tribasic copper sulphate=Not Applicable / Bordeaux mixture=Not Applicable; ARfD: Copper oxychloride=Not Applicable / Tribasic copper sulphate=Not Applicable / Bordeaux mixture=Not Applicable

Copper compounds=Approved / Copper hydroxide=Approved / Copper oxide=Approved / Copper oxychloride=Approved / Tribasic copper sulphate=Approved / Bordeaux mixture=Approved

IARC (carcinogenicity)

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

Good to know

• One of the pesticides allowed under organic JAS (copper hydrate wettable powders and dusts, and copper sulfate for making Bordeaux mixture). It is approved in the EU, but designated a “candidate for substitution” (a substance to be considered for replacement if a safer alternative exists), and its use rate is capped because copper builds up in soil.

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)

Sources

• FAMIC (Food and Agricultural Materials Inspection Center), pesticide registration information (as of Sept. 30, 2026) (Japanese)
• WHO Recommended Classification of Pesticides by Hazard 2019
• EU Pesticides Database (Copper compounds / Copper hydroxide / Copper oxide / Copper oxychloride / Tribasic copper sulphate / Bordeaux mixture)

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 Copper, sulfur and others (including those allowed under organic JAS)

• Sulphur
• Potassium hydrogen carbonate