Sodium nitrite
Sodium nitrite (E250) is a curing salt used in bacon, ham, and cured meats to fix colour and prevent botulism. Under cooking and digestion it can form nitrosamines, some of which are carcinogenic, and the WHO/IARC classifies processed meat as carcinogenic to humans.
Sodium nitrite preserves cured meats: it inhibits Clostridium botulinum, gives cured meat its pink colour, and adds flavour. It is authorised in the EU at limited levels.
The safety concern is that nitrite can react with amino acids to form N-nitroso compounds (nitrosamines), some of which are carcinogenic. The IARC classifies processed meat (which typically contains nitrite) as "carcinogenic to humans" (Group 1), and EFSA has tightened intake limits. Risk relates to overall processed-meat consumption rather than a single ingredient.
On the label
- E-number
- E250
- INS number
- INS 250
- Functional class
- Preservative
- Also known as
- Nitrite · Curing salt · Preservative 250 · INS 250
Frequently asked questions
The evidence is nuanced. Sodium nitrite is used to cure processed meats, and in 2015 the WHO’s IARC classified processed meat as a Group 1 carcinogen (causes colorectal cancer), with about an 18% higher bowel-cancer risk per 50 g eaten daily. Nitrite can contribute to forming N-nitroso compounds (nitrosamines), some carcinogenic, though how much this specifically adds to the overall risk is not fully established.
Mainly as a preservative: it inhibits dangerous bacteria (notably Clostridium botulinum, which causes botulism) and helps prevent spoilage. It also fixes the characteristic pink/red colour and adds cured flavour. Removing it creates food-safety challenges unless other preservation methods replace it.
Mainly cured and processed meats — bacon, ham, hot dogs, salami, sausages and other deli/cured products — where it is used in small amounts as a preservative and colour fixer. It is not typically added to fresh, unprocessed meat.
Yes, E250 remains authorised in the EU. In its 2017 re-evaluation, EFSA set a safe Acceptable Daily Intake of 0.07 mg per kg of body weight per day and concluded that nitrites added within permitted limits are safe for consumers — though exposure from all dietary sources combined could exceed the ADI for some groups such as children. Its use is restricted to specified maximum levels, not unlimited.
Nitrosamines are compounds that can form when nitrites react with amines from proteins, in food or in the body, and some are known to cause cancer. In 2017 EFSA judged that at approved additive levels nitrites’ contribution to overall nitrosamine exposure is of low concern, but noted pre-formed nitrosamines already present in some processed meats were a greater concern at high consumption. EFSA said more research was needed.
No official body defines a fully “safe” amount, but risk rises with quantity. WHO/IARC data indicate roughly an 18% higher colorectal-cancer risk per 50 g of processed meat eaten daily, and Cancer Research UK advises eating processed meat as little as possible and limiting red meat to about three portions a week. This is general dietary guidance, not individual medical advice.
Yes — it contains no animal-derived material. It is an inorganic salt manufactured industrially. In practice it is found almost only in cured meat, which is not. The same applies to a vegetarian diet.
Yes — the additive itself contains no gluten. A gluten-free claim belongs to the finished product, though — check the pack, not the additive.
It is an inorganic salt manufactured industrially and contains no animal-derived material, so the additive itself is not inherently non-halal. Certification applies to a finished product rather than to an additive, so a halal certification mark on the pack is the authoritative signal. It is overwhelmingly used in cured meat, so the meat itself — not the additive — is what determines the product's status.
Sodium nitrite has a genuine protective role: it blocks Clostridium botulinum in cured meat. The documented concern is that it can form nitrosamines, some of which are carcinogenic, and the IARC classifies processed meat as carcinogenic to humans (Group 1). EFSA re-evaluated nitrites in 2017 and kept an acceptable daily intake, concluding that exposure from additive use stays within safe levels for most people.