ESC is the premature initiation of cracking and embrittlement of a plastic due to the simultaneous action of stress and strain and contact with specific fluids. This definition provides the key to the problem of predictability. Failure is due to a combination of influences, which would not cause the same problems if encountered individually.
Approximately 15% of all failures of plastics components in service are caused by ESC. Such failures may be costly or life threatening, and consequently the phenomenon has been the subject of intensive research for more than 40 years. This research has revealed a great deal about the casual mechanism, but has not yet brought us to the ideal position of being able to predict and prevent the occurrence of ESC in all situations.