... exposed to air.Specification: Na2S (%): 60%MinFe: 1500PPM, 150PPM, 80PPM, 50PPM, 30PPM, 20PPM, 15PPM, 10PPM Max1500PPMNa2S(%)60.0MinNa2CO3(%)5.0MaxWater Insoluble ... .0Max/2.0MaxWater Insoluble(%)0.2MaxFe(%)0.015Max/0.008Max 50PPM/30PPMNa2S(%)60.0MinNa2CO3(%)2.0MaxWater Insoluble(%)0.2MaxFe(%)0.005Max ...