... 21-4 Appearance: White crystal powder 1-Hydroxy Ethylidene-1,1-DiphosphonicAcid (HEDP)CAS No. 2809- ... under high pH value, hard to be hydrolyzed, and hard to be decomposed under ... 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid; Hydroxyethylidene-1,1-diphosphonicacid(HEDP); 1-HYDROXYETHYLIDENEDIPHOSPHONIC ACID;Hydroxyethylidene Diphosphonic acid(HEDP); 1-hydroxy-1,1-Ethanediyl ester 1-Hydroxy Ethylidene-1,1 ...