Industrial Strength DRAIN CLEAN is a highly active acid based drain opener. DRAIN CLEAN works extremely fast, freeing stopped up drains of organic waste, grease, fats, sludge, paper, cloth sanitary napkins, rags, soap, detergent build up and food particles. DRAIN CLEAN loosens and removes lime and rust build up in drain lines. DRAIN CLEAN is extremely powerful and concentrated, extreme care must be exercised with its use.