Potassium nitrate

E number E252INS 252CAS 7757-79-1

Used as a preservative — Codex also lists it as colour retention agent.

Potassium nitrate, historically called saltpetre, is used in slow-cured meats and some cheeses, where it is gradually reduced to nitrite.

Where it is and isn’t permitted

Status of Potassium nitrate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted, with conditions21 CFR 172.160retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

1 food category

highest permitted level 35 mg/kg

CXS 192-1995 Table One, INS 252, food category 01.6.2retrieved 2026-09-07

What it is made from

Mined or manufactured by neutralising nitric acid with potassium. It is the oldest of the curing salts, in use long before its mechanism was understood.

  • Vegan
  • Vegetarian
CAS registry number
7757-79-1
InChIKey
FGIUAXJPYTZDNR-UHFFFAOYSA-N
PubChem
CID 24434

Every name it appears under

64 recorded names. A label may use any of them.

E number

  • E252

INS number

  • 252

CAS registry number

  • 7757-79-1

As it appears in regulation

  • Potassium nitrate

Other names

  • Attitude Adult Fluoride-free-Sensitive-Spearmint
  • Caswell No. 697
  • CCRIS 3667
  • Collo-Bo
  • Dr. Sheffield Sensitive Care
  • E 252
  • EPA Pesticide Chemical Code 076103
  • European Pharmacopoeia Reagent Conc.
  • HSDB 1227
  • INS NO.252
  • INS-252
  • Jason Total Protection Sensitive
  • Kali nitricum
  • Kalii nitras
  • Kaliumnitrat
  • Kiss My Face Sensitive
  • Kiss My Face Sensitive Fluoride-Free Whitening-Citrus Mint
  • KNO3
  • Niter
  • Nitrate of potash
  • Nitre
  • Nitric acid potassium salt (1:1)
  • Nitric acid, potassium salt
  • Nitrogen and oxygen isotopes in nitrate, NIST(R) RM 8568
  • Potassium nitrate
  • Potassium nitrate (JAN/USP)
  • Potassium nitrate (KNO3)
  • Potassium Nitrate ACS grade
  • Potassium Nitrate Standard Solution
  • Potassium nitrate(DOT)
  • Potassium nitrate, 99.99% trace metals basis
  • Potassium nitrate, 99.999% trace metals basis
  • Potassium nitrate, ACS reagent, >=99.0%
  • Potassium nitrate, anhydrous, 99.99% trace metals basis
  • Potassium nitrate, AR, >=99.5%
  • Potassium nitrate, BioUltra, >=99.5% (T)
  • Potassium nitrate, BioXtra, >=99.0%
  • Potassium nitrate, cell culture tested
  • Potassium nitrate, JIS special grade, >=99.0%
  • Potassium nitrate, LR, >=99.5%
  • Potassium nitrate, NIST(R) SRM(R) 193
  • Potassium nitrate, p.a., 99%
  • Potassium nitrate, Puratronic(R)
  • Potassium nitrate, ReagentPlus(R), >=99.0%
  • Potassium nitrate, SAJ first grade, >=99.0%
  • Potassium Nitrate, Trace metals grade 99.99%
  • Potassium standard for AAS, ready-to-use, in nitric acid
  • Potassium-nitrate
  • Salt peter
  • Salt peter (VAN)
  • Saltpeter
  • saltpetre
  • Schmidts
  • Schmidts WONDERMINT TOOTH AND MOUTH
  • Sensitive Teeth
  • Sensitive Tooth Paste
  • Sensodyne (TN)
  • SprinJene Natural Sensitivity and Gum
  • Vicknite

Systematic names

  • potassium nitrate

Hazard reference values

Values set by assessing bodies. A body that has not set a value is not listed here.
TypeValuePopulationAssessed byOpinion
ADI3.7 mg/kg bw/dayconsumersEFSA ANS2017

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07
  • gsfa retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/potassium-nitrate.json