A composition for cleaning a combustion engine system. The composition comprises a hydrocarbon. The hydrocarbon comprises respective first and second hydrocarbons. The first hydrocarbon comprises a lubricant, wherein the lubricant has a flash point, measured according to ASTM D93, of less than 80° C. The second hydrocarbon comprises an aromatic hydrocarbon, wherein the aromatic hydrocarbon has a flash point, measured according to ASTM D93, of greater than 62° C. The composition further comprises an oxygen donor. The oxygen donor comprises respective first and second oxygen donors. The first oxygen donor comprises a hydroxyl group and has a flash point, measured according to ASTM D93, of from 45° C. to 95° C. The second oxygen donor comprises a carbonyl group or an ether group and has a flash point, measured according to ASTM D93, of from 50° C. to 120° C.