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E251PreservativeModerate concern
Sodium Nitrate
In plain words
The short version
A slow-acting curing agent that is gradually converted to nitrite by bacteria during long meat aging.
Why we flag it amber
A curing salt that slowly turns into nitrite, which keeps cured meat safe and pink but can form nitrosamines — compounds linked to cancer. That trade-off is why we flag it.
Safety profile
ADI of 3.7 mg/kg body weight. The safety concerns mirror those of nitrite, since nitrate is converted to nitrite by oral and gut bacteria. Drinking water with high nitrate levels is regulated separately due to risk of infant methemoglobinemia.
The detail
Mined as a natural deposit (Chile saltpeter) for centuries and later synthesized industrially. One of the earliest meat-curing agents known to humans.
Used in dry-cured hams, prosciutto, and traditional sausages where a long curing time is needed. Bacterial action gradually reduces nitrate to nitrite.
Colorless crystalline solid, highly soluble in water. Stable in dry conditions; reduced to nitrite by Micrococcaceae and other bacteria during curing.
Permitted in the EU and US for specific uses. In the EU, nitrates are allowed in certain meat products, certain cheeses, and pickled herring and sprat. Regulation (EU) 2023/2108 lowered the maximum amounts that may be added: for example, 90 mg/kg (as nitrate ion) in non-heat-treated meat products from 9 October 2025, and 75 mg/kg in hard, semi-hard and semi-soft cheese from 9 October 2026. In the US, sodium nitrate may be used in cured meat products other than bacon, and FDA allows up to 500 ppm in smoked, cured sablefish, salmon and shad.
Sources
- EFSA — Re-evaluation of sodium nitrate (E 251) and potassium nitrate (E 252) as food additives (2017) — European Food Safety Authority (EFSA Journal 2017;15(6):4787), 2017. ADI 3.7 mg/kg bw; nitrate-to-nitrite conversion in saliva
- Commission Regulation (EU) 2023/2108 of 6 October 2023 amending Annex II to Regulation (EC) No 1333/2008 and the Annex to Regulation (EU) No 231/2012 as regards nitrites (E 249-250) and nitrates (E 251-252) — Official Journal of the European Union (via Publications Office), 2023. New EU maximum added nitrate levels (meat, cheese, fish)
- 21 CFR 172.170 — Sodium nitrate — US eCFR (Office of the Federal Register), 2026. US FDA permitted uses and 500 ppm limit
- 9 CFR 424.21 — Use of food ingredients and sources of radiation (USDA FSIS, meat and poultry) — US eCFR (Office of the Federal Register), 2026. US meat use of nitrate as a source of nitrite
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.