... 99% Synonyms:Propyl gallate, propyl ester of gallic acid, n-propyl ester of 3,4,5-trihydroxybenzoic acid, propyl 3,4,5-trihydroxybenzoateMolecular Formula ... % max , 110 oC for 4hSulfated ash0.1% maxFree Acid (as Gallic Acid)0.5% maxChloride Organic compounds (as CL)100mg/kg ... & dry place (<25 °C). Preserve in tight containers, protected from light, and avoid contact with metals.Shelf Life:24 months ...