Four curing salts sit in this family: potassium nitrite E249, sodium nitrite E250, sodium nitrate E251 and potassium nitrate E252. Nitrites act more directly; nitrates can be reduced to nitrite during longer curing.
E249 · E250 · E251 · E252
4 linked additive entriesFour curing salts sit in this family: potassium nitrite E249, sodium nitrite E250, sodium nitrate E251 and potassium nitrate E252. Nitrites act more directly; nitrates can be reduced to nitrite during longer curing.
They help control harmful bacteria and contribute to the colour and flavour of cured products. That technological purpose does not settle the wider diet question. The FSA’s 2025 evidence review found the human health evidence mixed and highlighted nitrosamine formation, cooking conditions and high processed-meat intake as important context.
The extra oxygen atom is not a trivial spelling difference. Nitrite is more reactive. Nitrate from E251 or E252 can act as a reservoir that microorganisms convert during curing, while E249 and E250 supply nitrite directly. That is why the four codes can appear in different curing methods.
Vegetables contribute much of normal dietary nitrate, while processed meats are an important source of dietary nitrite. The surrounding food matters: vegetables also bring vitamin C, polyphenols and fibre, whereas proteins and high-temperature cooking can influence formation of N-nitroso compounds.
A product label tells you which curing salt is present, not the amount consumed across a diet or the nitrosamine level after cooking. The practical reading is specific: identify the code, distinguish nitrite from nitrate, then consider frequency and portion in the context of official processed-meat advice.
4 entries, linked to the full evidence page
What it is: A curing salt used in place of, or with, sodium nitrite. It turns cured meat pink and blocks the bug behind botulism.
What it does: Locks the pink colour into cured meat. It blocks the bacterium behind botulism, which is why cured meat keeps.
Where you may see it: Bacon, ham, salami, frankfurters, luncheon meat and pate. Labels list it as potassium nitrite or E249.
Read evidence and sourcesWhat it is: A curing salt used in bacon, ham and salami. Labels may call it curing salts.
What it does: Stops the bacteria behind botulism, and keeps bacon and ham pink.
Where you may see it: Bacon, ham, salami, chorizo, frankfurters, luncheon meat, corned beef and pate. Label: sodium nitrite, E250 or curing salts.
Read evidence and sourcesWhat it is: A curing salt, also known as Chile saltpetre. It is used in slow-cured hams, salami and some cured fish.
What it does: It releases nitrite slowly as the food cures. That blocks the bacteria behind botulism and holds the pink colour.
Where you may see it: Dry-cured and fermented meats such as ham, salami and chorizo. Also long-cured bacon and some cured fish. Listed as E251.
Read evidence and sourcesWhat it is: A curing salt, also known as saltpetre. Curing bacteria slowly turn it into nitrite.
What it does: The nitrite it releases stops the bacteria behind botulism. It also holds the pink colour in meat that is cured slowly.
Where you may see it: Dry-cured ham, salami, hard sausages, some cured fish and some cured cheeses. Listed as potassium nitrate, saltpetre or E252.
Read evidence and sourcesThe table summarises fields from NutraSafe’s reviewed additive records. “Check” is deliberate: a code can identify the substance without revealing every feedstock, processing aid or certification decision.
| Code | Additive | Source note | Dietary source check |
|---|---|---|---|
| E249 | Potassium nitrite | mineral | Vegan: listed as suitable; Halal: check source/certification |
| E250 | Sodium nitrite | mineral | Vegan: listed as suitable; Halal: check source/certification |
| E251 | Sodium nitrate | mineral | Vegan: listed as suitable; Halal: check source/certification |
| E252 | Potassium nitrate | mineral | Vegan: listed as suitable; Halal: check source/certification |
Jurisdiction note: Great Britain’s electronic register is the official public list for GB authorisations from 1 April 2025. Northern Ireland and EU positions can differ. Presence in NutraSafe’s reference library is not a claim of unrestricted current authorisation in every jurisdiction or food.
Sodium nitrite is E250.
Cured and processed meats are the best-known use, but conditions of authorisation can cover other defined food categories.
The chemicals are related, but the food matrix and accompanying compounds differ, so the FSA review does not treat the contexts as interchangeable.
The family explanation uses current official UK regulatory and labelling material, relevant FSA or EFSA topic evidence, and specialist dietary guidance where stated. Additive-specific claims remain on the linked detail entries.
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