Sheet or Molded Polystyrene :

Polystyrene (PS) can be used for making disposable plastic cutlery and dinnerware, CD "jewel" cases, smoke detector housings, license plate frames, plastic model assembly kits, and many other objects where a hard, economical plastic is desired Production methods include thermoforming (vacuum forming) and injection molding.

Polystyrene dishes and other laboratory containers such as test tubes and microplates play a key role in biomedical research and science.
For these uses, articles are almost always made by injection molding, and often sterilized post-molding, either by irradiation or by treatment with ethylene oxide.
Post-mold surface modification, usually with oxygen-rich plasmas, is regularly done to present polar groups.
Much of modern biomedical research relies on the use of such products; they therefore play a critical role in pharmaceutical research.