Volatile matter (at 135 °C), not more than 2.0 percent.
Water-soluble matter, not more than 0.3 percent.
Matter insoluble in carbon tetrachloride, not more than 1.5 percent.
p-Toluidine, not more than 0.1 percent.
1,4-Dihydroxyanthraquinone, not more than 0.2 percent.
1-Hydroxy-4-[(4-methylphenyl)amino]-9, 10-anthracenedione, not more than 5.0 percent.
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.
Total color, not less than 96.0 percent.
21 C.F.R. §74.1206