There are two training requirements for the transportation of hazardous materials. The US Department of Transportation (DOT) regulations that cover transportation of hazardous materials by all modes of transportation and the International Air Transport Association (IATA) dangerous goods regulations which cover transportation of hazardous material by air.
Training in DOT regulations is available from commercial training companies such as Transportation Skills Programs Inc. They conduct a one day seminar annually in Hawaii usually in January. Alternatively, the DOT has free online training that meets the basic requirements for DOT awareness and safety training (http://hazmat.dot.gov/training/mods/mod.htm).
In order to ship hazardous material by air, IATA training is required. This training is given locally about twice a year by the Transportation Development Group (http://www.logisticstraining.com). Details about the training and registration information are available on their web-site. Prior to taking the IATA training it is desirable to have had the basic DOT training.
DOT regulations require refresher training every three years and IATA regulations require refresher training every two years. DOT and IATA regulations are updated annually and therefore the current manuals for these regulations need to be purchased annually (e.g., Hazardous Materials, Substances and Wastes Compliance Guide, and IATA Dangerous Goods Regulations).