... 1,1-Diphosphonic Acid (HEDP) CAS:2809-21-4 Appearance: White crystal powder 1-Hydroxy Ethylidene-1,1-DiphosphonicAcid (HEDP)CAS ... to be hydrolyzed, and hard to be decomposed under ordinary light and heat conditions. Its acid/alkali and chlorine oxidation tolerance are ... as electric power, chemical industry, metallurgy, fertilizer, etc.. In light woven industry, HEDP is used as detergent for metal and ...