UK label guide · checked 2 October 2026
E252 is potassium nitrate
It is a preservative used in some cured foods. On a UK label, check for preservative: E252 or preservative: potassium nitrate. The code identifies an ingredient, not a verdict on the whole food.
See the label check
The short answerE252 = potassium nitrateA three-step check at the shelf
Find the code or name
Read the ingredients, not just the front. UK additive labels give the function, then an E number or specific name. Look for E252 or potassium nitrate after 'preservative'.
Read the food context
Nitrates are used in some cured meat, fish and cheese products. If it is a cured meat, consider the food and how often you eat it, not this code in isolation.
Compare the full list
Check another product beside it. A different label may use E250 (sodium nitrite), E251 (sodium nitrate), or no listed nitrate additive. Absence of E252 alone does not establish a healthier choice.
Nitrate and nitrite are different
These nearby codes are easy to mix up. This is a name check, not a ranking of which product is safest.
What the evidence actually says
Great Britain authorises E252 for specified uses. Authorised does not mean unlimited use: the conditions depend on the food category. The GB register covers England, Scotland and Wales; Northern Ireland follows separate rules.
EFSA's 2017 evaluation retained an acceptable daily intake for nitrate of 3.7 mg per kg of body weight per day. EFSA found exposure from nitrate additives generally within that level, while total intake from all dietary sources may exceed it. The ingredient list cannot tell you the amount in a serving.
Nitrate can be converted to nitrite, and nitrosamine formation is one reason regulators keep reviewing these additives. The UK FSA's 2025 evidence review discusses possible health associations and remaining uncertainty. It does not provide a way to calculate your risk from spotting E252 on one package.
Practical takeaway: identify the additive, check the food category and full ingredient list, then compare products. One E number cannot rate the whole product.
For a broader view, see our E-number lookup and processed-meat label guide.
Frequently askedquestions
Short answers for UK shoppers reading an E252 label.
What is E252 on a food label?
E252 is potassium nitrate, a preservative used in some cured foods. On a UK ingredients list, look for 'preservative: E252' or 'preservative: potassium nitrate'.
Is E252 the same as E250?
No. E252 is potassium nitrate; E250 is sodium nitrite. Nitrate can be converted to nitrite during curing, but the codes identify different additives. E251 is sodium nitrate.
Is potassium nitrate safe in food?
Great Britain authorises E252 for specified food uses. EFSA's 2017 assessment retained a nitrate acceptable daily intake of 3.7 mg per kg of body weight per day. An ingredient list tells you that the additive is present, not how much you consume. Research on nitrate, nitrite and processed meat does not let you judge a single product's risk from E252 alone.
Does E252 mean a food is ultra-processed?
Not by itself. Read the whole ingredients list and the type of food. A single preservative code cannot establish a food's NOVA group.
Sources
The claims on this page are based on these publications.
- UK FSAGB authorisation register: potassium nitrate (E252)
- UK FSAHow additives appear on UK ingredients lists
- FSSScottish guidance on additive names and E numbers
- EFSA2017 assessment of nitrates and nitrites added to food
- UK FSA2025 review: safety of nitrates and nitrites as food additives
- FAONOVA food classification and ultra-processed foods
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