A hypoermic needle-exchange program is a sometimes controversial social policy, based on the philosophy of harm reduction where injection drug users can obtain hypodermic needles and associated injection equipment at little or no cost. These programs are called "exchanges" because many require exchanging used needles for an equal number of new needles. In addition to sterile needles, syringe exchange programs typically offer other services such as: HIV and Hepatitis C testing; alcohol swabs; bleach and sterile water; aluminum "cookers"; containers for needles and many other items.