Probably one of the most useful classes any environmental manager can take is the EPAﾒs reactivity chart class. This course sets out to define chemicals into Reactive Group Numbers RGNs and further delineates the breakdown of each chemical buy comparison when mixed. This course is a must have for any hazardous materials manager or chemical distributor. A hazmat employee who performs any of these functions may not perform the function unless he or she has been trained in the requirements of hazardous materials (generally: identification, classification, labeling, marking, placarding, packaging, etc.) that apply to that function. It is the duty of each hazmat employer to comply with the applicable requirements of this subchapter and to ensure that each hazmat employee is thoroughly instructed each hazmat employee. In addition, hazmat employers must ensure that each of hazmat employee is tested by appropriate means on the training subjects covered in Sec. 172.704.