A polymer is a substance composed of chains chemically bonded repeated structural units. Plastics are a type of polymer.
History and specifics
In 2376 during a Jem'Hadar attack on Deep Space 9 a cloud polymer gas was released from a temp bank of atmospheric regulators. A Benzite, Monyodin, was exposed to the gas which dissolved the alveoli in his lungs, resulting in his death. (DS9 - Avatar novel: Avatar, Book One)