Rescue XS is a super extra strength drain opener and maintainer. Rescue XS will clear the toughest of clogs caused by hair, paper, grease, soap scum and other organic matter. Rescue XS contains no acids, bleaches or fillers and is 100% active. Rescue XS is harmless to cast iron, PVC, ABS, steel or rubber gaskets, grease traps and septic tanks. Will not stain or discolor porcelain tubs, sinks or chrome. Use only for tough jobs like slow X-Ray sink drains and condensate lines on HVAC drain pan.