Kleen Waste holding tank treatment is a highly efficient and concentrated dual-action enzyme and quaternary designed to control waste, tissue, and various buildup with regular use. Deodorizes, cleans lines, lubricates valves and components while breaking down waste and all household toilet tissue. Effective in black and grey tanks, Formaldehyde Free, and 100% biodegradable. Safe for septic systems and can be used to clean and deodorize holding tanks, boat head, drains, disposals, bilges, portable potties and outhouses. Leaves holding tank or head clean and smelling fresh for up to 30 days.