Thiabendazole
The short version
A benzimidazole fungicide for citrus wax — removed from the EU food-additive list in 1998 (it is regulated there as a pesticide) but still common in US imports.
A fungicide for citrus, regulated in the EU as a pesticide rather than a food additive. In 2022 EFSA noted it meets the EU criteria for an endocrine disruptor (thyroid), while judging the current ADI still protective. That's why we flag it.
Safety profile
ADI of 0.1 mg/kg body weight per day from the EU pesticide review, in line with JECFA's ADI of 0–0.1 mg/kg body weight. In 2022 EFSA noted that thiabendazole meets the EU criteria for endocrine disruption (thyroid) but judged that the current ADI should still be protective. US limits are residue tolerances set per commodity, for example 10 ppm on citrus fruit. Its EU food-additive entry was repealed in 1998 because thiabendazole residues are covered by pesticide residue legislation. The medical anthelmintic dose is hundreds of times higher than dietary exposure.
Sources
- WHO JECFA database — Thiabendazole (veterinary drug evaluation, 2002) — World Health Organization / JECFA, 2002. safety: JECFA ADI 0–0.1 mg/kg bw
- EU — Directive 98/72/EC amending Directive 95/2/EC on food additives other than colours and sweeteners — Publications Office of the European Union (EUR-Lex), 1998. regulation: EU food-additive entry repealed in 1998
- EFSA — Evaluation of confirmatory data following the Article 12 MRL review for thiabendazole (2022) — European Food Safety Authority (EFSA Journal), 2022. safety: EU ADI 0.1 mg/kg bw per day; thyroid endocrine-disruption finding
- US eCFR — 40 CFR 180.242 Thiabendazole; tolerances for residues — U.S. Government Publishing Office / Office of the Federal Register (eCFR), 2026. regulation: US residue tolerances (citrus 10 ppm)
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.