Boric Acid
The short version
A traditional preservative restricted to caviar in the modern EU food code.
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Safety profile
ADI of 0.16 mg/kg body weight per day, expressed as boron (EFSA 2013). JECFA did not allocate an ADI for boric acid. Boron as borate is almost completely absorbed (over 90%) and excreted mainly in urine; EFSA notes no evidence of boron accumulation at intakes of 0.4–3 mg/day. At high doses boric acid causes reproductive and developmental toxicity in animal studies. The narrow EU permission reflects the unique storage challenges of caviar combined with very small per-capita consumption.
Sources
- WHO JECFA database: Boric acid, no ADI allocated (1961) — World Health Organization / JECFA, 1961. JECFA did not set an ADI
- EFSA: Safety of calcium fructoborate as a novel food, EFSA Journal 2021;19(7):6661 (restates EFSA 2013 boron ADI) — European Food Safety Authority, 2021. ADI 0.16 mg boron/kg bw/day set by EFSA ANS Panel 2013; boron absorption and excretion
- EUR-Lex: Regulation (EC) No 1333/2008, consolidated text of 18 August 2026 (Annex II, E 284) — European Union (EUR-Lex), 2026. EU use limited to sturgeon caviar at 4 g/kg as boric acid
- FDA: Substances Added to Food inventory, Boric acid — U.S. Food and Drug Administration. US: listed only for food-contact/technical uses, not as a direct food preservative
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.