This specification covers the requirements fo structural foams which may be applied in the body shop and used for structural reinforcement of body cavities such as pillars, rails and other areas where lightweight structural enchancement may be required. These materials may be die cut or preforemd to expand and fill any cavity while going through ELPO bake ovens and yield structural integrity to the parts with which they come in contact. While ging parts with whch meet this specification yield structural integrity to existing steel structure, they may not be considered as a main structural componenet.