This rule amends the Department's Hazardous Materials Regulations to allow the continued use in intrastate service of certain cargo tanks for the carriage of anhydrous ammonia in States where this practice was permitted until the Hazardous Materials Regulations were extended to cover both interstate and intrastate transportation of certain materials, including anhydrous ammonia, and prohibited such practice. This is not a major rule. It is supported by the majority of the persons who submitted comments on the notice of proposed rulemaking. It is designed to rectify a situation which would cause hardship in the agricultural community and the industries which serve it.