a bag may or may not be disposable; however, even a disposable bag can often be used many times, for economic and environmental reasons. on the other hand, there may be logistic or hygienic reasons to use a bag only once. for example, a garbage bag is often disposed of with its content. a bag for packaging a disposable product is often disposed of when it is empty. similarly, bags used as receptacles in medical procedures, such as the colostomy bag used to collect waste from a surgically diverted biological system, are typically disposed of as medical waste. many snack foods, such as pretzels, cookies, and potato chips, are available in disposable single-use sealed bags.