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E251 · Preservatives

Sodium nitrate

High risk carcinogenpreservative

Converts to nitrite; same nitrosamine concern.

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

What it is

Sodium nitrate (E251) is a salt used in the meat industry. Unlike nitrites (which act immediately), nitrates act as a slow-release reservoir. Over time, bacteria in the meat slowly convert the nitrates into nitrites.

How it is used in food

The storage form of curing chemistry.

Commonly found in
  • Dry-cured sausages (like salami and chorizo)
  • Aged hams (like prosciutto)
  • Certain cheeses (to prevent late-blowing defects)

Health and safety

Bacteria convert nitrate to nitrite, feeding the same nitrosamine pathway as E250.

Because E251 converts into nitrite (E250) during the curing process, it carries exactly the same safety concerns as direct nitrite additives.

Converts to nitrites

general population · evidence: established

Bacterial action converts nitrate to nitrite, which can then form carcinogenic nitrosamines.

EFSA re-evaluation of nitrates

Contributes to the overall processed-meat cancer risk.

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.

Identification on labels

E-number
E251

Also printed asChile saltpeter

How it is made

Manufactured by reacting nitric acid with sodium carbonate.

  1. Synthesis — Nitric acid is neutralized with sodium carbonate to produce sodium nitrate.

Worth knowing

Your own saliva bacteria steadily convert dietary nitrate to nitrite.

Conclusion

The ultimate hazard is the formation of carcinogenic nitrosamines in the body or during high-heat cooking. Like all nitrate/nitrite additives, health authorities recommend minimizing consumption.

References

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Entry last reviewed 2026-07-28.

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