PHMSA issued a final rule revising the HMR for lithium battery transportation by aircraft. The rule prohibits the transportation of lithium batteries in the cargo area of passenger aircraft. It also requires them to be no more than 30% charged during transport when not packed with or contained inside equipment. Additionally, the rule modifies certain provisions including marking requirements, requests for an extension on the compliance date, and exception for batteries used for medical devices. The final rule will be effective as of January 20, 2023.