The yields of hydrogen, cyclohexene, and bicyclohexyl are lower in gamma irradiated solutions of duroquinone in cyclohexane than they are in cyclohexane alone; duroquinone is consumed during the radiolysis. Product yields are functions of the duroquinone concentration; values at 75 mM duroquinone are: G(H2= 3.50; G(C6H10) = 0.70; G((C6H11)2) = 0.21; G(-DQ) = 7. The product from the quinone is shown to be probabIy a quinone containing a substituted cyclohexyl group. Duroquinone solutions in cyclohexane are photochemically inert, and duroquinone is not consumed in irradiated benzene solution. The reduction of hydrogen yield by duroquinone is attributed to electron scavenging; the reduction of cyclohexene and bicyclohexyl yields and the consumption of duroquinone is attributed to scavenging of cyclohexyl radicals (by hydrogen abstraction from the duroquinone methyl groups). The yield of cyclohexyl radicals in duroquinone-quenched solution is thus found to be 5.5–6.8, and their origin is attributed to the reactions of “hot” (unscavengable) hydrogen atoms.