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E285PreservativeElevated concern
Sodium Tetraborate (Borax)
In plain words
The short version
A borate salt permitted essentially only to preserve and firm sturgeon caviar; restricted elsewhere.
Why we flag it
Borax, allowed in the EU essentially only for caviar. Borates can build up in the body and affect fertility and development at higher doses, which is why its use is so narrow — and why we flag it.
Safety profile
Borates are restricted because they accumulate in the body and can affect fertility and development at higher doses; the caviar use is a narrow low-level exception. Not permitted as a general food additive in most countries.
The detail
A boron mineral salt (borax), refined from borate ores. Far better known as a cleaning and laundry agent.
In food it is permitted essentially only as a preservative for sturgeon caviar, where it firms the eggs and extends shelf life.
White crystalline powder, water-soluble, mildly alkaline.
EU — permitted only for caviar (with E284); banned as a general food additive in the US and most countries.
Sources
- EFSA ANS Panel — Re-evaluation of boric acid (E 284) and sodium tetraborate (borax) (E 285) as food additives (2013) — European Food Safety Authority (EFSA Journal), 2013. Safety: reproductive/developmental effects; caviar-only EU use; group ADI 0.16 mg boron/kg bw
- JECFA database — Borax (sodium tetraborate) — WHO / Joint FAO/WHO Expert Committee on Food Additives, 1961. JECFA allocated no ADI for borax as a preservative
- Commission Regulation (EU) No 1129/2011 establishing the Union list of food additives (Annex II to Reg. 1333/2008) — Publications Office of the EU (Official Journal), 2011. EU: E 285 permitted only in sturgeon eggs (caviar), max 4 g/kg as boric acid, alongside E 284
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.