Environmental Stress Cracking of Polymeric Materials 
Gases and liquids act on thermoplastics to produce an effect known as Environmental Stress Cracking (ESC). An essential characteristic of ESC is that, with an appropriate medium, damage only occurs under mechanical stress, the amount of which may be considerably less than the nominal limiting load for a given material. Even high impact thermoplastics, such as polycarbonates, behave as brittle materials under relatively low stress in the presense of some solvents (e.g. for polycarbonates: Toluene or toluene/isooctane mixtures).