2002年,有关部门曾对18家超市、食品店抽查不同食品包装袋和保鲜膜,结果发现,许多塑料包装制品存在严重问题。保鲜膜通常安全的保鲜膜是一种叫“线性低密度聚乙烯材料”制成的。但是现在有许多超市、食品店的保鲜膜都是用“聚氯乙烯”,即平常所说的pvc材料制成的。pvc是一种硬塑料,要将它制成柔软透明的薄膜,必须添加增塑剂。但是这些增塑剂会缓慢地从塑料中“外渗”挥发出来。例如大家非常熟悉的塑料台布,新买来时柔软异常, In 2002, relevant departments had spot-checked different food packaging bags and cling film on 18 supermarkets and food stores. As a result, it was found that many plastic packaging products had serious problems. The cling film is usually a safe cling film made of a material called “linear low density polyethylene.” However, many supermarkets and food stores now use “PVC,” which is commonly known as pvc. Pvc is a hard plastic. To make it a soft, transparent film, plasticizers must be added. However, these plasticizers slowly evaporate out of the plastic. For example, plastic tablecloths that people are very familiar with are soft and abnormal when they are newly purchased.