Role of lungs : Removes large amount of CO2 and also water.
Liver : Removes bilirubin, biliverdin, cholesterol, degraded steroids, hormones, vitamins and drugs.
Skin : Sweat glands help in removal of sweat containing NaCl, small amount of urea, lactic acid, etc. Sebaceous glands helps in removal of sterols, hydrocarbons and waxes through sebum.