Acetic acid

Acetic acid is the organic compound responsible for vinegar's sharp taste and distinctive aroma. As a food additive it serves as an acidity regulator, preservative, and flavouring agent, lowering pH to inhibit bacterial and mould growth. It is found naturally in fermented foods and is added to pickles, sauces, condiments, bread, and a wide range of processed products.

JECFA has assigned acetic acid an ADI of "not specified" — its highest safety classification — meaning no numerical daily intake limit is required. This reflects the fact that acetic acid is a natural intermediate in human metabolism, completely broken down through normal biochemical pathways. This assessment, first established in 1965, has been consistently upheld by safety authorities worldwide.

Acetic acid is approved without restriction in every major food regulatory jurisdiction including the EU, US (GRAS), UK, Australia, Japan, and Vietnam. It is one of the most ubiquitous food ingredients in the world, present in vinegar, pickled vegetables, hot sauces, mayonnaise, mustard, sourdough bread, and many canned products. There are no significant safety concerns for healthy adults at typical dietary exposures. Individuals managing gastro-oesophageal reflux may prefer to limit acidic foods generally, but this is a dietary preference rather than a toxicological concern.