Star Brite Instant Fresh Toilet Cleaner Highly effective way to deal with the boat's holding tank that eliminates the need for multiple chemicals • Non-formaldehyde, non-staining, biodegradable formula. • Latest technological lubricants keep drain valves from sticking. • Breaks down waste quickly and efficiently. • One ounce treats five gallons. • Fresh pine scent controls holding tank odors fresh lemon scent controls holding tank odors. • Complies with EU criteria for biodegradable products; • contains lubricants that prevent drain valves from sticking