The NUK Baby Bottle Cleanser is more effective at cleaning baby bottles and accessories than hot soapy water alone. Its natural enzymes break down the dried on milk protein, pulp and juice residues, which can cause baby stomach upsets. The natural, PH neutral formula of the NUK Baby Bottle Cleanser is both baby safe and effective at cleaning baby bottles, teats, soothers and accessories. Environmentally Friendly: Natural, biodegradable ingredients and 100% recycled bottle.