Other brands of treatment are sold in tablet form, which means the user can open the protective package and drop the tablet into a toilet easily. Contact with the water may activate the enzymes, but the bacteria will not contact human skin. Sometimes the treatment is in powdered form and must be measured out by hand before flushing. Incidental contact with the ingredients is possible, so hand protection is recommended. A liquid form of septic tank treatment is often used for emergency situations, much like a powerful drain cleaner on a clogged sink.