a medical bag composed of a laminate comprising an inner low - density polyethylene layer , an intermediate layer of ethylene - vinyl acetate copolymer , ethylene - propylene type elastomer , or ethylene - butene - 1 type elasomer , and an outer low - density polyethylene layer . this bag has excellent sanitariness , flexibility , transparency , and heat - resistance , therefore , is suitable for use as a container of blood and various medicinal liquids .