epsom salt ( magnesium sulphate hepta ) is white crystal ,soluble in water, low heavy metal, ISO9001 certified supplier epsom salt ( magnesium sulphate hepta ) is white crystal ,soluble in water, low heavy metal, ISO9001 certified supplier. White crystalPurity:99%minMgO16%minMg:9.5%minS:12.5%minAs:3ppm maxPb:10ppm maxPackage in 25kg bags Any questions , please feel free to ask us