A chemiluminescent composition comprising an oxalate component comprising an oxalate ester and a solvent, an activator component comprising a peroxide compound and a catalyst and a fluorescer contained in the oxalate component and/or the activator component. The solvent contained in the oxalate component comprises a propylene glycol dihydrocarbyl ether containing one to three propylene moieties and each hydrocarbyl moiety contains up to 8 carbon atoms and is independently selected from the group consisting of straight chain alkyl, branched chain alkyl, cycloalkyl, aryl, alkaryl and aralkyl groups.