Provides for six hardnesses of vulcanized rubber joint rings manufactured from natural rubber, synthetic rubber (chloroprene, butyl, styrene-butadiene and polyisoprene rubber) and mixtures of natural and synthetic rubber. Tensile strength, elongation, compression set, water absorption, root growth inhibitor, and sampling, marking and packaging are specified. Appendices cover purchasing guidelines, methods of test, quality control information, root growth inhibitor, handling, packing and transport of rubber ring samples for assessment after use.