Medical devices are constructed of many materials and substances. Some substances, which are in other fields considered “hazardous” are necessary for use in medical devices as they have proven net benefits for health. For example, Phthalates such as DEHP are mainly used in medical devices to help replace natural rubber and glass to eliminate kinked tubing and reduce personal injury. DEHP used in blood bags has preservative properties for red blood cells hence prolonging the life of the blood itself. In instances where these substances are used, safety data must be supported by a risk/benefit assessment, which includes the evaluation of alternatives.