The Federal hazardous materials transportation law requires the Secretary of Transportation to ensure that, to the extent practicable, regulations governing the transportation of hazardous materials in commerce are consistent with standards adopted by international authorities (49 U.S.C. 5120(b)). Harmonization enhances safety, facilitates compliance, and improves the efficiency of the global transportation system by minimizing the regulatory burden on the public thus promoting trade. After a thorough review of the provisions recently adopted by various international regulatory bodies, PHMSA has identified areas in the HMR in which harmonization with international regulations will provide an enhanced level of safety, an economic benefit, or in many instances both increased safety and economic benefits. As a result, this rulemaking action would amend the HMR, where appropriate, to maintain alignment with international standards that will become effective as of January 1, 2021, and consequently facilitate the safe global trade of hazardous materials. Proposals in this rulemaking action would include, but are not limited to: New classification and packaging for infectious waste of Category A; Updates to International Organization for Standardization (ISO) cylinder manufacturing and testing standards, and addition of two new entries to the organic peroxides table; Evaluation criteria for damaged lithium batteries; Expansion of existing options to transport large robust articles (i.e., refrigerating machines) unpackaged on pallets, in crates, or in appropriate overpacks to include other large robust articles containing gases; and Incorporation by reference of various international standards and regulations, including the latest editions of the UN Model Regulations, the IMDG Code, the ICAO Technical Instructions, and ISO technical standards applicable to cylinders.