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Potassium acetate

also: Potassium ethanoate · Acetic acid potassium salt

The potassium salt of acetic acid (vinegar acid), used to regulate acidity and act as a mild preservative in food.

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An ingredient list from the cooked and cured meats aisle

Chicken Breast (96%), Acidity Regulators (Potassium Acetate, Acetic Acid), Corn Starch, Salt, Stabiliser (Triphosphates), Dextrose, Glucose Syrup

E261Acidity regulator · Synthetic

Potassium acetate

Potassium acetate is the potassium salt of acetic acid, the acid that gives vinegar its sharp taste.

VeganVegetarian

69

of the 43,325 UK supermarket foods we checked declare E261 in their ingredients

That is 0.2%, counted by its code or its name.

Only 23% of these labels print “E261”. Most use the name: look for “potassium acetate”.

Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted

How common it is in UK food, by aisle

  • Cooked and cured meats42 products2.2% of 1,938
  • Fresh meat, poultry and fish16 products0.3% of 4,835
  • Bread and bakery5 products0.1% of 3,682

What potassium acetate is, what it does and where you will see it

What is it?

Potassium acetate is the potassium salt of acetic acid, the acid that gives vinegar its sharp taste. It forms when acetic acid reacts with potassium hydroxide or potassium carbonate. It appears as a white, hygroscopic (moisture-attracting) powder or granules and dissolves readily in water.

What does it do?

In food, potassium acetate adjusts and stabilises pH, making the environment more acidic or buffering it against pH swings. This acidity control inhibits the growth of spoilage bacteria and some moulds, extending shelf life. It also contributes a faintly sour, vinegar-like note to flavour. As an alternative to sodium acetate, it delivers the same acidity-regulation function while adding potassium rather than sodium to the product.

Where you will see it

Potassium acetate is used in pickled vegetables, condiments, sauces, marinades, ready meals, and some bread and bakery products. It appears occasionally in low-sodium or reduced-sodium reformulations where manufacturers substitute it for sodium acetate (E262) to lower sodium content. On a UK label it will read 'potassium acetate' or 'acidity regulator (E261)'.

What the science says

Potassium intake from food additives

Potassium acetate contributes potassium to the diet. For most people this is unremarkable, as dietary potassium is beneficial and widespread deficiency is more common than excess. However, people with kidney disease or those taking certain medications (such as potassium-sparing diuretics or ACE inhibitors) may need to manage total potassium intake carefully, as impaired kidneys struggle to excrete excess potassium, which can affect heart rhythm.

Individuals with chronic kidney disease or on potassium-sparing medications should monitor total dietary potassium, including contributions from additives such as potassium acetate, due to risk of hyperkalaemia.

RegulatoryNHS clinical guidance on chronic kidney disease and diet

Acetic acid equivalents and food safety

The acetate part of potassium acetate is metabolised by the body in the same way as acetic acid from vinegar, which is a normal intermediate in human metabolism. EFSA reviewed acetates as a group and found no grounds to restrict it arising from the acetate ion at levels used in food. The European Food Safety Authority set no numerical ADI, which indicates the intake from food uses is not considered to require a specific upper limit.

EFSA's Panel on Food Additives and Nutrient Sources concluded that acetates used as food additives raise no safety concern at the levels relevant to food use, and no numerical ADI was considered necessary.

2017Regulatory reviewEFSA Panel on Food Additives and Nutrient Sources (ANS), re-evaluation of acetic acid and its salts

Where it stands with the regulators

Approved for use in the UK and EU
Legal basis
UK FSA approved-additives list and assimilated EU Regulation 1333/2008 (Annex II); also covered under the acetates group re-evaluation by EFSA
Permitted foods
Pickled vegetables and condiments; Sauces and dressings; Bread and fine bakery products; Ready meals and prepared foods; Reduced-sodium reformulations
Maximum levels
Quantum satis (use at the lowest level needed to achieve the technical purpose) for most permitted categories
Safe-intake limit (ADI)
No numerical ADI set
History
Acetates including potassium acetate have a long history of use and were re-evaluated by EFSA in 2017. The re-evaluation confirmed continued approval at quantum satis levels. No restrictions or bans have been applied in the UK or EU. The additive was carried over into UK law following the end of the EU transition period.

Who should be careful

People with chronic kidney disease, or those taking potassium-sparing diuretics or ACE inhibitors, may need to track all potassium sources in their diet including from food additives. Look for 'potassium acetate' or 'acidity regulator (E261)' on the label.

The honest read

Potassium acetate is chemically straightforward: it breaks down in the body to potassium and acetate, both of which are ordinary parts of normal metabolism. The acetate ion is essentially what the body produces from vinegar digestion. EFSA reviewed the entire acetate group in 2017 and found no issues at food-use levels. The only realistic context in which it merits attention is for people who must limit potassium for medical reasons, a consideration that applies to all potassium-containing foods and additives, not to anything specific about this one.

Common questions about potassium acetate

Is E261 banned in the UK?

No. Potassium acetate is approved for use in the UK under the assimilated version of EU Regulation 1333/2008, carried over after the EU transition period. It remains on the UK FSA's approved-additives list.

Is potassium acetate just vinegar?

Not exactly, but it is closely related. Potassium acetate is the potassium salt of acetic acid, the acid in vinegar. When it dissolves in food, it releases acetate, which the body handles in the same way as acetic acid from vinegar. The potassium component comes from the salt, not from vinegar itself.

What foods contain E261?

Pickled vegetables, condiments, sauces, marinades, some breads, and ready meals. It also appears in low-sodium reformulations where manufacturers replace sodium acetate with potassium acetate to reduce sodium content.

Is E261 vegan?

Yes. Potassium acetate is derived from acetic acid and a potassium source, both mineral or plant-derived. It contains no animal ingredients and is considered vegan.

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