This NPRM proposed that cars built for TIH service be capable of surviving both head and shell puncture tests. These new designs had to be implemented within 8 years after the rule was finalized. See HM-246 NPRM Previous articleCPC-1187 Implementation of the AAR Standard for Tank Cars Transporting Toxic Inhalation Hazard (TIH) CommoditiesNext article P-1525 Industry Petition for Interim TIH Standard