(((Phosphonomethyl)imino)bis(ethylenenitrilobis(methylene)))tetrakisphosphonic acid, ammonium salt 15827-60-8 70714-66-8 EINECS 274-798-6 Phosphonic acid, (((phosphonomethyl)imino)bis(2,1-ethanediylnitrilobis(methylene)))tetrakis-, ammonium salt