The Materials Transportation Bureau proposes to amend Part 173 of  Title 49 CFR to authorize the use of nonspecification cargo tanks, and of specification cargo tanks with a design pressure of 250 psig, for the transport of anhydrous ammonia m intrastate commerce under certain conditions. This action is necessary because individual states have adopted the Department's Hazardous Materials Regulations which require the use of DOT Specification MC-330 and MC-331 cargo tanks with a design pressure of 265 psig. The intended effect of this action is to allow continued use of nonspecification cargo tanks and specification cargo tanks with a design pressure of 250 psig for the transportation of anhydrous ammonia m intrastate commerce until they are taken out of service and replaced with new tanks that meet DOT requirements.