21 C.F.R. § 74.250
(a) Identity.
(b) Specifications. Orange B shall conform to the following specifications:
Volatile matter (at 135 °C.), not more than 6.0 percent. Chlorides and sulfates (calculated as the sodium salts), not more than 7.0 percent. Water insoluble matter, not more than 0.2 percent. 1-(4-Sulfophenyl)-3-ethylcarboxy-5-hydroxypyrazolone and 1-(4-sulfophenyl)-3-carboxy-5-hydroxypyrazolone, not more than 0.7 percent. Naphthionic acid, not more than 0.2 percent. Phenylhydrazine-p-sulfonic acid, not more than 0.2 percent. The trisodium salt of 1-(4-sulfophenyl)-3-carboxy-4-(4-sulfonaphthylazo)-5-hydroxypyrazole, not more than 6.0 percent. Other subsidiary dyes, not more than 1.0 percent. Lead (as Pb), not more than 10 parts per million. Arsenic (as As), not more than 1 part per million. Total color, not less than 87.0 percent.