Hydrochloric acid
The same acid your stomach produces naturally, added to food to control acidity during processing.
What is it?
Hydrochloric acid is a strong inorganic acid, a water solution of hydrogen chloride gas. In food use it is produced to food-grade purity and used in dilute form. It is chemically identical to the gastric acid the human stomach secretes to digest food.
What does it do?
Acts as an acidity regulator: it lowers the pH of a food system precisely during processing, enabling enzyme activity, controlling fermentation, or adjusting flavour balance. It is also used to hydrolyse starches and proteins in the manufacture of glucose syrups and hydrolysed vegetable protein. Because it is volatile and rapidly neutralised by the food matrix, very little residual acid remains in the finished product.
Where you will see it
Most commonly used in glucose syrup and starch hydrolysis, gelatine manufacture, beer and brewing adjuncts, and some cheese processing. The volumes used are industrial-process quantities, not added directly to consumer dishes. On a UK ingredient label it will appear as 'hydrochloric acid' or 'E507'.
What the science says
Residual levels in finished food
Hydrochloric acid added during processing is largely consumed in neutralisation reactions or evaporates before the product reaches the consumer. Residual chloride ions that remain are indistinguishable from naturally occurring chloride (as in table salt) and at typical dietary levels present no distinct route of harm. EFSA's panel on food additives reviewed acidity regulators and found no toxicological concern at the levels resulting from food use.
EFSA concluded that hydrochloric acid and its food-use salts (E507-E509) do not raise a safety concern at the levels used in food processing, and set no numerical ADI.
Handling and occupational hazard
Concentrated hydrochloric acid is corrosive and presents genuine hazards in industrial handling: fumes irritate the respiratory tract and concentrated liquid causes chemical burns. These are occupational and accidental-exposure risks, not hazards from eating food processed with food-grade dilute acid. The distinction matters: the hazard of the concentrated industrial chemical does not transfer to the trace residues in processed food.
Concentrated hydrochloric acid fumes are classified as a respiratory irritant under occupational health regulations; food-additive use involves dilute forms and is governed by good manufacturing practice.
Where it stands with the regulators
Who should be careful
No specific population group needs to avoid foods processed with E507. People on medically supervised low-chloride diets should note that processed foods may contribute dietary chloride, but this applies to many common ingredients, not specifically to E507.
The honest read
Hydrochloric acid sounds alarming but is the same substance the human stomach makes in quantity every time you eat. In food processing it is used in dilute, food-grade form during manufacture, not poured into a finished product. By the time food reaches a shelf, neutralisation reactions and evaporation mean residual levels are negligible. EFSA reviewed it and found nothing to flag at current use levels. The industrial handling hazard of concentrated acid is real, but it has no bearing on what a shopper encounters in a processed food.
Related additives
Common questions
Is E507 banned in the UK?
No. E507 is on the UK FSA approved-additives list and is permitted under assimilated EU Regulation 1333/2008. It is not subject to any restriction or ban in the UK or EU.
Hydrochloric acid sounds dangerous. Is it harmful in food?
Concentrated hydrochloric acid is corrosive and hazardous in industrial settings. In food use it is highly dilute and used during processing, not added to the final product in significant amounts. It is chemically the same acid the stomach produces naturally during digestion.
What foods contain E507?
It is primarily a manufacturing process acid rather than an ingredient that stays in a product. Foods most likely to involve it during production include glucose syrups, gelatine, some cheeses, hydrolysed vegetable proteins, and certain beers. It would be declared on the label as 'hydrochloric acid' or 'E507' if present as a functional additive in the final product.
Is E507 vegan?
Yes. Hydrochloric acid is a synthetic inorganic acid with no animal-derived components. It is suitable for vegan and vegetarian diets.
Sources
- UK FSA Approved Additives and E Numbers
- EFSA ANS Panel, Re-evaluation of hydrochloric acid (E 507), EFSA Journal 2018
- EU Regulation No 1333/2008 on food additives
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