This International Standard specifies a method for determining the chemical resistance properties of glass-reinforced thermosetting plastics (GRP) pipes and fittings in a deflected condition for nominal sizes DN 100 and larger. In conjunction with ISO 10928, this International Standard provides a method for evaluating the effect of a chemical environment on the interior of a pipe or fitting after a specified period of time. Test conditions and requirements are specified in the referring standards such as ISO 10467. NOTE It has been found that the effect of chemical environments can be accelerated by strain induced from deflection; hence, it is frequently referred to as strain corrosion.