Acidity or alkalinity: Agitate 1 gram of the color additive with 25 milliliters of water and filter. The filtrate shall be neutral to litmus paper.
Matter insoluble in dilute hydrochloric acid, not more than 0.5 percent.
Lead (as Pb), not more than 10 parts per million.
Arsenic (as As), not more than 1 part per million.
Mercury (as Hg), not more than 1 part per million.
Aluminum oxide (Al2 O3), not less than 50 percent.
21 C.F.R. §73.1010