Potassium nitrate is the preservative the food industry lists as E252. In our table it is high risk: it takes 30 points off the additive subscore, which is worth a third of a product's score (about 10 of the 100).
- The key finding, from IARC: Group 2A with a dietary route (IARC Monographs Vol. 94 (2010), Group 2A, ingested nitrate under nitrosating conditions)
- Flagged for young children. Set only where EFSA’s own exposure assessment shows toddlers or children exceeding or approaching the ADI, or where a regulator used explicitly child-specific language. It is already in our top class, so the flag cannot move it higher.
- Where you meet it. It turns up in 7 of the 10,000 packaged foods scanned most on Open Food Facts, most often in processed meats. Nine in ten of those foods are sold in Europe (counted 26 Sep 2026).
- 3 citations from IARC, EFSA and the FDA, each one below.
What Potassium nitrate does to a score
A packaged food's additive subscore starts at 100 and loses points for each additive on the label; that subscore is a third of the final score. Potassium nitrate takes 30 points off the additive subscore, which is worth a third of a product's score (about 10 of the 100). Scan the pack in Sito and the score you get is the one for your own child's age, with this additive named in the reasons. How we score has the whole method.
See what is in your own cupboard
Scan a packaged food and Sito names the additives in it, then scores the product out of 100 for your child's age.
What the sources found
Every classification in our table comes from the citations below, and nothing else. Each finding is our one-line summary of what the source concluded, with the source and reference beside it.
-
IARC
Monographs Vol. 94 (2010), Group 2A — ingested nitrate under nitrosating conditions
Group 2A with a dietary route. -
EFSA
10.2903/j.efsa.2017.4787
ADI 3.7 mg nitrate/kg bw/day; additive use alone does not exceed it; all dietary sources exceed the ADI for all age groups at the mean, with children/toddlers the flagged groups. -
FDA
21 CFR §172.160 (potassium nitrate)
Permitted in the US in specified cured products.
Why this class
IARC Group 1 or 2A with a dietary exposure route; or EFSA has withdrawn or negated a safety conclusion; or EFSA’s own exposure assessment finds a child age group exceeding the ADI at mean intake; or the substance is banned or formally being phased out for food use by the EU, by the US FDA, or under a US state law.
Our confidence in this row's classification is medium. Medium or low does not mean the evidence is weak; it means something about the row is still being pinned down, usually a regulatory status confirmed from one source rather than two.
Questions parents ask
Is Potassium nitrate (E252) safe for kids?
High risk. In Sito it takes 30 points off the additive subscore, which is worth a third of a product's score (about 10 of the 100). It is flagged for young children, and it is already in our top class, so the flag cannot move it higher. The finding we rely on: Group 2A with a dietary route (IARC Monographs Vol. 94 (2010), Group 2A, ingested nitrate under nitrosating conditions).
What is E252?
E252 is the E number for Potassium nitrate, a preservative. Open Food Facts tags it en:e252.
Next to it on the label
The E numbers either side of E252 in our table, then the closest preservatives by number.
- Natamycin (E235), no risk identified
- Hexamethylene tetramine (E239), moderate risk
- Potassium nitrite (E249), high risk, flagged for young children
- Sodium nitrite (E250), high risk, flagged for young children
- Sodium nitrate (E251), high risk, flagged for young children
- Acetic acid (E260), no risk identified