Sodium Propionate

About This Product

Sodium propionate, C3H5NaO2 with CAS number 137-40-6, is supplied as a white crystalline powder or granule, freely soluble in water and appreciably more soluble than the calcium salt. That solubility difference is what determines which propionate a process uses. Where the antifungal agent has to be applied as a spray onto grain or silage, dosed into a liquid stream, or incorporated into an aqueous formulation, the calcium salt's limited solubility becomes a handling problem and the sodium salt is specified instead. The other consideration is the cation itself. Calcium interferes with some formulations, precipitating with phosphates, sulfates and carbonates and disturbing chemically leavened or buffered systems; sodium does not. Against that, the sodium contribution has to be accounted for where sodium loading is controlled. The antifungal mechanism is identical, depending on undissociated propionic acid crossing the fungal cell membrane, and it therefore works best in mildly acidic conditions while remaining useful nearer neutral pH, where benzoate and sorbate are inactive. It is used in liquid grain and silage treatment, feed preservation, industrial mould control, water-based formulations and as an antifungal additive. Bio Green Chem supplies sodium propionate to specification on assay, free acid and alkali, loss on drying, iron, chloride and heavy metals.