Regulatory status in the UK and EU
Formic acid does not appear in Annex II of the UK's assimilated version of EU Regulation 1333/2008, the definitive list of additives permitted in food for human consumption. The E-number sequence in that list jumps from E235 (Natamycin) to E239 (Hexamethylene tetramine), with E236 absent. The same is confirmed in the EU's own consolidated text of Regulation 1333/2008 (EUR-Lex, June 2024): E235 is followed directly by E239 in Part B of Annex II, with no entry for E236, E237 or E238. The UK FSA approved-additives list similarly contains no entry for E236. It was also absent from the UK Preservatives in Food Regulations 1989. There is no published EFSA re-evaluation opinion on formic acid as a human food additive.
E236 is not listed in Annex II of the assimilated UK version of EU Regulation 1333/2008. The additive sequence skips from E235 to E239, with no entry for formic acid or its formate salts (E237, E238).
2024RegulatoryUK legislation.gov.uk, Regulation (EC) No 1333/2008 Annex II (version as of 28 June 2024)
The consolidated EU text of Regulation (EC) No 1333/2008 (EUR-Lex, version 02 June 2024) lists no entry for E236, E237 or E238 in Annex II Part B. The sequence runs from E235 (Natamycin) to E239 (Hexamethylene tetramine).
2024RegulatoryEUR-Lex, Consolidated text of Regulation (EC) No 1333/2008, CELEX:02008R1333-20240602
The UK Food Standards Agency approved-additives list contains no entry for E236 formic acid.
RegulatoryUK Food Standards Agency, Approved additives and E numbers
The Preservatives in Food Regulations 1989 (SI 1989/533) list permitted preservatives in Schedule 1; formic acid and its formate salts do not appear.
1989RegulatoryUK legislation.gov.uk, SI 1989/533 Schedule 1
JECFA toxicology evaluation
The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has evaluated formic acid on more than one occasion. An early assessment set a provisional acceptable daily intake of 0-3 mg/kg bodyweight; a later assessment reported 0-5 mg/kg bodyweight. In both cases the committee noted that long-term toxicity data were incomplete and that the ADI was conditional or provisional. In animal studies, higher doses produced methaemoglobinaemia and enzyme inhibition, though no cumulative toxic effects were identified at the assessed intake levels.
JECFA established a provisional acceptable daily intake of 0-3 mg/kg bodyweight for formic acid, based on available biochemical studies and its role as a normal metabolic intermediate. Long-term toxicity data were acknowledged as lacking.
1965Regulatory reviewJECFA, WHO Food Additives Series 5, Monograph 265 (Formic acid)
A later JECFA assessment reported a conditional ADI of 0-5 mg/kg bodyweight and noted the committee could not set an unconditional ADI because long-term animal toxicity studies were absent. It recommended additional metabolism studies in humans.
1966Regulatory reviewJECFA, FAO Nutrition Meetings Report Series 38a, Monograph 003 (Formic acid)
In animal studies, sodium formate caused methaemoglobinaemia at oral doses around 50 mg/kg in dogs. At very high doses (3,000-4,000 mg/kg) toxic effects including heart congestion were observed. No cumulative effects were noted at lower doses.
1965AnimalJECFA, WHO Food Additives Series 5, Monograph 265 (Formic acid)
Use in animal feed
EFSA has assessed formic acid specifically as a preservative and acidifier in animal feed and drinking water for all animal species, concluding it is effective and poses no safety concern to animals at recommended use levels. This is entirely separate from any assessment for human food use. The primary commercial application of formic acid is in silage and fishmeal preservation.
EFSA's Panel on Additives and Products or Substances used in Animal Feed concluded that formic acid is safe for use in feed for all animal species and categories at maximum proposed dose levels, and that residues in animal products (meat, milk, eggs) do not raise a concern for consumers.
2014RegulatoryEFSA, Scientific Opinion on the safety and efficacy of formic acid when used as a technological additive for all animal species, EFSA Journal 12(7):3827
Formate toxicity at high doses (not relevant to food additive use)
Formate is the toxic metabolite responsible for the severe effects of methanol poisoning. At high accumulation it inhibits cytochrome c oxidase, disrupting mitochondrial energy production, and causes an anion-gap metabolic acidosis. The retina and optic nerve are particularly vulnerable. These toxic mechanisms operate at formate concentrations far above any conceivable food additive exposure; they are relevant when methanol is ingested in significant quantity, not from dietary formic acid in the trace amounts found naturally in food.
Formate inhibits cytochrome c oxidase, the terminal enzyme of the mitochondrial electron transport chain. This mechanism underlies the retinal toxicity and metabolic acidosis seen in methanol poisoning.
1991Lab + animalLiesivuori J, Savolainen H, Pharmacology and Toxicology: Methanol and formic acid toxicity: biochemical mechanisms
