Cargo and Hazard Awareness
Hazard awareness
Tanker cargo may be flammable, corrosive, toxic, or otherwise regulated. The tanker endorsement lets you drive bulk tank vehicles; it does not replace the hazardous materials endorsement or the required knowledge. Before loading, verify the shipping paper, product identity, hazard class, placards, and compatibility with the tank and previous cargo. Confirm that valves are correctly set and that grounding/bonding is used for flammable liquids to control static electricity. During loading and unloading, stay attentive, monitor hoses and fittings, and know the emergency shutoff location.
Traps
A frequent trap is thinking any tanker can carry any liquid. Residue can react with a new product, and a tank may not be rated for the material. Another trap is placarding by memory: use the shipping paper and regulations, and remember that some quantities are excepted. Do not assume a tanker endorsement permits hazmat routes, tunnels, or parking that local rules prohibit.
Worked example
You are loading a flammable liquid. Before connecting the hose, verify the product, check the tank's last cargo, confirm the placard, and attach the grounding cable to a clean metal contact. Keep the hose clear of traffic and attend the loading. Rule of thumb: if the product identity, compatibility, or grounding is uncertain, stop and ask before opening a valve.