Zinc methionine sulfate, CAS Reg. No. 56329-42-1, may be safely used in accordance with the following prescribed conditions:
Zinc content-19 to 22 percent.
C5H11NO2S "DL-methionine"-46 to 50 percent.
Cadmium-not more than 0.05 part per million.
21 C.F.R. §172.399