Saran Wrap was originally made out of a chemical called polyvinylidene chloride, or PVDC.

保鲜膜最初是由一种叫做聚偏二氯乙烯或 PVDC 的化学物质制成的。

But around that time, concerns started to surface about chlorine-containing compounds like PVDC.

但大约在那个时候， 人们开始对 PVDC 等含氯化合物表示担忧。

And not that dry-cleaning isn’t fascinating or anything, but PVDC turned out to have some interesting properties of its own.

并不是说干洗没有吸引力或其他任何东西， 而是 PVDC 本身具有一些有趣的特性。

When this came to light, SC Johnson made the responsible decision to eliminate PVDC from all of its products by 2004.

此事曝光后， 庄臣做出负责任的决定， 到 2004 年从其所有产品中淘汰 PVDC。

See, depending on the temperature, one square meter of a thin film of PVDC will let about 1 to 5 grams of water vapor pass through it in a day.

看，根据温度，一平方米的 PVDC 薄膜在一天内会让大约 1 到 5 克的水蒸气通过。