Section 333.320 - Permitted combinations of active ingredients(a) Resorcinol identified in § 333.310(b) may be combined with sulfur identified in § 333.310(f) .(b) Resorcinol monoacetate identified in § 333.310(c) may be combined with sulfur identified in § 333.310(f) . 75 FR 9776 , Mar. 4, 2010