Potassium Nitrate
The short version
Saltpeter — a slow-release curing agent that converts to nitrite during meat ageing.
A traditional curing salt that converts to nitrite in the meat, protecting against botulism but able to form nitrosamines — compounds linked to cancer. That trade-off is why we flag it.
Where it comes from
Naturally occurring as the mineral niter; also produced industrially by reaction of potassium chloride with nitric acid. One of the oldest meat-curing agents — used for millennia in traditional preserved meats.
How it's used
Used in dry-cured hams, salami, and some traditional cheeses where slow nitrate-to-nitrite conversion by microbial reductases gives a gradual, sustained curing action. Typical use levels 100–300 mg/kg. Also a flame retardant and traditional pickling agent.
Safety profile
ADI of 0–3.7 mg/kg body weight. Lower direct toxicity than nitrite but converts to nitrite in storage and digestion, where the same N-nitrosamine concerns apply. The combined nitrite + nitrate dietary load (including from vegetables) drives the risk profile.
Physical & chemical properties
Colorless to white crystals, highly soluble in water. Stable in dry storage. Strong oxidizer.
Regulation worldwide
Permitted in the EU and globally for charcuterie and certain cheeses with maximum residual limits.
Educational information only. Not medical or dietary advice.