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Publication 52 - Hazardous, Restricted, and Perishable Mail >
3 Hazardous Materials
A hazardous material is any article or substance designated by the U.S. Department of Transportation as being capable of posing an unreasonable risk to health, safety, or property during transportation. In international commerce, hazardous materials are known as “dangerous goods.” For definitions of other terms that relate to hazardous materials, see Appendix D.