The Materials Transportation Bureau (MTB) is renewing for two years the exceptions (statutory exemptions) for specified quantities of radioactive materils found in 49 CFR 173.4, 173.421- 1 and 173.421-2. These exceptions permit the continued transportation by passenger-carrying aircraft of certain quantities of radioactive material under the existLng restrictions. These materials do not present a significant hazard to passengers or crew on an aircraft. This action is necessary on an emergency basis because the existing exceptions will expire on May 3, 1985. Under the provisions of section 553 of the Administrative Procedure Act, agencies are permitted to issue a rule in final form when notice and public procedure are impracticable, unnecessary, or contrary to the public interest. This emergency final rule, entitled "Exceptions for Specified Quantities of Radioactive Materials", has been determined not to be a major rule. Its effect will permit the continued transportation by passenger-carrying aircraft of certain quantities of radioactive materials. Delay in the renewal of these provisions would be contrary to the public interest because the limits imposed on the transport of these materials via passenger-carrying aircraft would have an adverse effect on the nuclear industry, and would disrupt routine and ongoing shipments which have been made safely for 10 years under the previous exceptions. Continuation of the exceptions will have a negligible environmental impact and will not impose any additional costs on shippers, carriers or consumers.