Bass Pro Shops Head and Holding Tank Treatment is a non-formaldehyde, non-staining, biodegradable formula with the latest technological lubricants to keep drain valves from sticking. Breaks down waste quickly and efficiently. This head tank treatment works in all portable and RV toilets. Size:32 oz. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Cleaning & Protectant.