Potassium Nitrate (E252) — What You Need to Know
What Is Potassium Nitrate?
Potassium nitrate, historically known as saltpeter, is a preservative used in cured meats and certain cheeses. It is either mined from natural deposits or synthetically produced. Like sodium nitrate, it serves as a slow-release source of nitrite during curing, and is particularly important in traditional European cheese-making to prevent defects caused by gas-producing bacteria.
What Is It Used For?
Used in cured meats for long-term preservation and in hard cheeses such as Gouda and Edam to prevent late blowing caused by Clostridium tyrobutyricum. Also traditionally used in dry-cured sausages and salami.
Safety Assessment
Known historically as saltpeter. Same concerns as sodium nitrate — converts to nitrite and potentially to nitrosamines. Traditionally used in cheese production (especially Gouda-type cheeses) to prevent late blowing caused by Clostridium tyrobutyricum. EFSA 2017 group re-evaluation. The conversion pathway: nitrate to nitrite to nitrosamines means all nitrate/nitrite additives share similar carcinogenicity concerns.
Based on current evidence, Potassium Nitrate is rated Questionable with a score of 4/10. This is 1.7 points below the average for preservatives (5.7/10). Last reviewed by regulators: 2017.
Commonly Found In
Always check the label for E252 or 'Potassium Nitrate'
▶Chemical Information
Frequently Asked Questions about Potassium Nitrate
Quick Facts
- E-Number
- E252
- INS Number
- 252
- Category
- Preservatives
- Origin
- Synthetic
- FDA Status
- Approved. Limited use in cured meat products.
- EFSA Status
- Re-evaluated 2017. Group ADI of 3.7 mg/kg bw/day as nitrate ion (shared with E251). Concerns over nitrate-to-nitrite conversion.
- ADI
- 3.7 mg/kg bw/day
- Last Review
- 2017
Quick Links
Related Additives
Other preservatives in the same family