Stearic or oleic acid, not more than 5 percent.
Cadmium (as Cd), not more than 15 parts per million.
Lead (as Pb), not more than 20 parts per million.
Arsenic (as As), not more than 3 parts per million.
Mercury (as Hg), not more than 1 part per million
Aluminum (as Al), not more than 0.5 percent.
Tin (as Sn), not more than 0.5 percent.
Copper (as Cu), not more than 95 percent and not less than 70 percent.
Zinc (as Zn), not more than 30 percent.
Maximum particle size 45[MICRO] (95 percent minimum).
Aluminum, zinc, tin, and copper content shall be based on the weight of the dried powder after being thoroughly washed with ether.
21 C.F.R. §73.1646