E251 - Sodium nitrate

At a glance

• Role: Preservative for long cures; slowly turns into nitrite during ripening
• Typical foods: Dry-cured meats (like salami and country ham) and some Swiss-style cheeses
• Why it’s used: Helps prevent dangerous bacteria and supports cured color and flavor
• Usual substitutes: Faster-acting sodium nitrite or other preservatives where allowed
• Safety: Strict legal limits and processing rules apply; most people’s nitrate intake actually comes from vegetables, not cured meats
• Label clue: Look for “sodium nitrate,” “E251,” or related curing agents on the ingredient list

Why is Sodium nitrate added to food?

Food makers use sodium nitrate in traditional, long-cured meats and some cheeses because it acts as a reservoir for nitrite, which releases slowly as the food ages. Nitrite controls harmful microbes such as Clostridium botulinum (the organism that produces botulinum toxin) and also helps set cured meat color and flavor. These uses are permitted under U.S. and EU rules when processors follow strict conditions and limits.¹² In the United States, its use in certain meat and poultry products is regulated as a curing agent alongside nitrite.³

What foods contain Sodium nitrate?

You’ll most often find sodium nitrate in:

• Long-cured meats that age for weeks or months, such as dry salami, country ham, and similar specialty products
• Some traditional, Swiss-style cheeses made with specific methods

On labels, it may appear as “sodium nitrate,” “E251,” or together with other curing agents such as sodium nitrite or potassium nitrate. In many quicker cures, makers use nitrite directly rather than nitrate.

What can replace Sodium nitrate?

Possible options depend on the food and local rules:

• Faster-acting curing agents: sodium nitrite or potassium nitrate in traditional recipes that allow them
• Other preservatives for non-cured foods: sorbic acid, potassium sorbate, sodium lactate, or potassium lactate where permitted
• Cure accelerators/antioxidants used with nitrite: sodium ascorbate or sodium erythorbate to help control nitrosamine formation and support color

The best substitute depends on the product’s safety needs, texture, and taste goals, as well as legal limits in the country of sale.

How is Sodium nitrate made?

Food-grade sodium nitrate is a refined inorganic salt supplied as a white, crystalline powder or granules. In the EU, it must meet identity and purity criteria set out in additive specifications, including tests for assay and limits on impurities.⁴ Manufacturers choose food-grade material that meets these specifications and handle it under good manufacturing practices.

Is Sodium nitrate safe to eat?

Regulators set strict limits on how much nitrate and nitrite can be added to foods, and on how those foods are processed. The European Food Safety Authority (EFSA) set an acceptable daily intake (ADI) for nitrate of 3.7 mg per kilogram of body weight per day, expressed as nitrate ion.² For most people, vegetables are the largest source of nitrate in the diet, not cured meats.⁵ In meats where curing agents are used, U.S. rules include processing steps (for example, the use of ascorbate/erythorbate in bacon) that help minimize the formation of nitrosamines, a group of compounds that can form under high-heat conditions.³

Does Sodium nitrate have any benefits?

Yes—its key benefit is food safety in long-cured products. Sodium nitrate slowly yields nitrite during curing, and nitrite inhibits Clostridium botulinum and helps produce the stable cured color and characteristic flavor of traditional cured meats.² This controlled release is especially useful in very long cures where a quick dose of nitrite alone would be depleted too soon.

Who should avoid Sodium nitrate?

• Infants under 6 months and people with conditions that increase the risk of methemoglobinemia (a blood disorder linked to excess nitrite) are more sensitive to nitrate/nitrite exposure; they should follow medical advice and avoid unnecessary sources.⁶
• Anyone told by a healthcare professional to limit nitrates or nitrites should check labels and choose products accordingly. If you are concerned about nitrosamines, avoid overcooking cured meats at very high temperatures.

Myths & facts

• “Nitrate-free” cured meats don’t always mean no nitrate or nitrite. Products cured with celery or similar ingredients still add nitrate/nitrite from natural sources and must carry qualifying label statements in the U.S.⁷
• Nitrates aren’t only “synthetic chemicals.” They occur naturally at high levels in many vegetables and contribute the majority of typical dietary nitrate intake.⁵
• “Nitrate and nitrite are unrelated.” In long cures, nitrate can be converted by microbes to nitrite, which provides the antimicrobial and color-forming functions.²
• “There are no limits.” Use is tightly controlled by law, including permitted foods, concentrations, and processing conditions.¹

Sodium nitrate in branded foods

You’re most likely to see sodium nitrate in artisan-style dry sausages, country hams, and some Swiss-type cheeses. Mainstream sandwich meats and hot dogs more often use nitrite directly, or different preservatives. Always check the ingredient list; curing agents are declared, often near salt and spices.

References

Footnotes

1. Sodium nitrate — 21 CFR 172.170. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-172/subpart-B/section-172.170 ↩ ↩²

2. Re-evaluation of nitrites (E 249–250) and nitrates (E 251–252) as food additives — EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/4786 ↩ ↩² ↩³ ↩⁴

3. Use of Food Ingredients and Sources of Radiation (curing agents; nitrosamine controls) — 9 CFR 424.21(c). https://www.ecfr.gov/current/title-9/chapter-III/subchapter-E/part-424/section-424.21 ↩ ↩²

4. Commission Regulation (EU) No 231/2012 — Specifications for food additives. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩

5. Nitrates in vegetables — EFSA Scientific Opinion. https://www.efsa.europa.eu/en/efsajournal/pub/689 ↩ ↩²

6. Toxicological Profile for Nitrate and Nitrite — ATSDR/CDC. https://www.atsdr.cdc.gov/toxprofiles/tp204.pdf ↩

7. FSIS Compliance Guideline: Statements That No Nitrate or Nitrite Added and “Uncured” Products — USDA FSIS. https://www.fsis.usda.gov/policy/compliance-guides/clarification-statements-no-nitrate-or-nitrite-added-and-uncured-products ↩