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E249 · Preservatives

Potassium nitrite

High risk carcinogenpreservative

Cured-meat nitrite; forms nitrosamines, IARC-classified pathway.

Category
Preservatives
Acceptable daily intake
0.07 mg/kg body weight/day (EFSA)
Vegan
Yes
Vegetarian
Yes

What it is

Potassium nitrite (E249) is a salt used to cure meats. It prevents the growth of Clostridium botulinum (which causes botulism) and gives cured meats their characteristic pink color and tangy flavor.

How it is used in food

Keeps cured meat pink and botulism-free.

Commonly found in
  • Cured ham and bacon
  • Sausages and hot dogs
  • Corned beef

Health and safety

Feeds the nitrosamine chemistry that underpins IARC’s processed-meat classification.

E249 is functionally identical to the more common Sodium nitrite (E250). The hazard lies not in the nitrite itself, but in what happens when it is heated.

Forms carcinogenic nitrosamines

general population · evidence: established

When heated, nitrites combine with proteins in meat to form nitrosamines, which the WHO classifies as Group 1 carcinogens (known to cause cancer).

EFSA re-evaluation of nitrites

Linked to colorectal cancer risks through nitrosamine formation.

Regulatory status

RegionStatusNotes
Australia & New Zealand
FSANZ
Restricted Permitted.
European Union
EFSA / European Commission
Restricted Authorised under Regulation (EC) No 1333/2008 with maximum added amounts, tightened in 2023 over nitrosamine formation in cured meat.
United States
FDA (Food and Drug Administration)
Restricted Approved with strict usage limits.

Identification on labels

E-number
E249

Alternatives to this additive

  • Celery powder — Contains naturally high levels of nitrates which convert to nitrites, providing a "natural" cure (though it forms the same nitrosamines).

How it is made

Produced industrially by reacting nitrogen oxides with potassium carbonate or potassium hydroxide.

  1. Synthesis — Nitrogen oxides are absorbed into a solution of potassium carbonate to form the nitrite salt.

Worth knowing

The potassium twin of sodium nitrite (E250).

Conclusion

When meat containing nitrites is cooked at high temperatures (like frying bacon), the nitrites react with amino acids to form nitrosamines, which are established human carcinogens. Consequently, health authorities advise limiting the consumption of all nitrite-cured processed meats.

References

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Entry last reviewed 2026-07-28.

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