This instruction establishes a provisional chemical resistance classification of unplasticized polyvinyl chloride with respect to 160 fluids. It is intended to give general indications on the possible use of non-plasticized poly(vinyl chloride) pipes for the conduction of fluids at temperatures of up to 20 and/or 60 0C and in the absence of internal pressure and external mechanical stresses such as , bending stress, stresses due to terrain, rolling loads and others.