Hazardous Materials Transportation DOT Refresher This 8 hour refresher course meets the training requirements of 49 CFR Parts 700-704. It is designed for those responsibilities for preparing Hazardous Materials and Wastes shipments by air, water, highway, or rail transportation.. Classroom material reviews classification, preparation of shipping papers, packaging, marking, labeling, compatibility and load segregation. Hands-on training includes preparation of multi-modal ...