Styrene (vinyl benzene) - The toxic precursor to the CD jewel case

• sweet-smelling and rapidly-evaporating aromatic hydrocarbon used to manufacture a variety of different plastics (including polystyrene/Styrofoam), synthetic rubber, resins, and insulators
• flammable and unstable, it likes to polymerize on its own slowly at room temperatures, and so is often stabilized with a polymerization inhibitor
• produced au naturel by the decarboxylation of cinnamic acid, a bacteria-opposing compound found in numerous plants (including, you guessed it, cinnamon!)
  
• is metabolized by the liver to, among other things, highly reactive epoxides that like to permanently bind to (by nucleophilic addition) and disrupt the function of cellular macromolecules including proteins and nucleic acids, leading to cytotoxicity, mutagenicity, and potentially carcinogenicity
• irritates the respiratory tract, possibly by directly binding to mucosal nerve endings, and can cause bronchitis and pulmonary edema (which can kill you)
• has been shown to cause CNS depression, impairment of long-term memory, and changes in liver histology (indicating possible liver damage) in rats
  

Gibbs BF, Mulligan CN. Styrene toxicity: an ecotoxicological assessment. Ecotoxicol Environ Saf. 1997 Dec;38(3):181-94. Review.