Happy Campers Odourfree Holding Tank Treatment is a natural formula that is environmentally friendly and biodegradable with no formaldehyde. It is safe, clean, easy to use and not chemically sensitive. Happy Campers Treatment liquifies water and household tissue is OK, it is powerful. It is the lowest cost product on the market today, do your math! 1 oz. treats thirty gallons. Costs less than .90 cents per treatment, most economical, first-class treatment available.