So adding small amounts of a chemical to the plastic – a special additive – allows the plastic to break down in the open air.

就是说在制造塑料袋时添加少量某种化学物质——一种特殊的添加剂——就会让塑料袋在户外自然降解。

At this company laboratory in North London they're testing how bags made with a special additive break down when exposed to sunlight, oxygen and heat.

伦敦北部一家公司的实验室里在研究添加了特殊添加剂的塑料袋如何在太阳光、氧气和热量下分解。