Thiabendazole
The short version
A benzimidazole fungicide for citrus wax — banned in EU food (2014) but still common in US imports.
It's allowed, but comes with clearer cautions — such as reactions in sensitive people, stricter limits, or contested safety. The Safety section below explains why.
Where it comes from
Discovered by Merck in 1961 as a veterinary anthelmintic; food-use as a post-harvest fungicide followed. Manufactured by condensation of thiazole and benzimidazole intermediates.
How it's used
Applied as a wax-incorporated post-harvest fungicide on citrus, stored apples, and pears to inhibit storage molds. EU food use revoked in 2014 (still permitted as an agricultural pesticide); US, Latin America, and Asia-Pacific markets continue to use it on imported citrus.
Safety profile
EU ADI revoked; US tolerance 0.05 mg/kg body weight. Higher reproductive and developmental toxicity signal than the orthophenylphenol class drove the EU revocation. The medical anthelmintic dose is hundreds of times higher than dietary exposure.
Physical & chemical properties
White to off-white crystalline powder. Insoluble in water; soluble in dimethyl sulfoxide and other polar solvents.
Regulation worldwide
Banned for food-additive use in the EU since 2014. Still permitted in the US, Latin America, and parts of Asia-Pacific with maximum residue limits.
Educational information only. Not medical or dietary advice.