Bulk Packages, Cargo Tanks, and Tank Vehicle Operations
What counts as bulk
A bulk packaging has a capacity greater than 119 gallons (450 L) for a liquid, greater than 882 pounds (400 kg) for a solid, or greater than 1,001 pounds water capacity for a gas. Bulk shipments skip some non-bulk packaging rules but trigger placarding at any quantity and add filling-limit and outage requirements - a tank is never filled to the top, because liquid expands with temperature.
Know your tank
Cargo tanks are built to specifications shown on the specification plate, and the plate plus current test and inspection markings must be present and in date. Common types: DOT-406 (MC-306) for flammable liquids such as gasoline, DOT-407 (MC-307) for many chemicals, DOT-412 (MC-312) for corrosives, DOT-331 (MC-331) for high-pressure liquefied gases such as propane, and DOT-338 (MC-338) for cryogenic liquids. A tank vehicle with a loaded cargo tank may also require the tank endorsement in addition to the hazmat endorsement.
Loading and unloading a tank
Park on level ground, set the parking brake, chock the wheels, and shut off the engine before transferring a flammable liquid. Bond the tank to the facility and ground it before opening any dome or valve, then keep the bonding cable connected until the transfer is finished and the openings are closed. Open domes slowly, stand upwind, and never leave the transfer unattended. Use the emergency shutoff and know where it is. Never smoke or allow ignition sources near the operation, and do not top off or overfill - respect the outage.
Traps
Questions confuse grounding (tank to earth) with bonding (tank to the source), or claim a tank may be left running during transfer. Others test the 119-gallon liquid threshold. Remember that an overfilled tank is a violation even if nothing spills at the dock.
Worked example
Loading gasoline at a terminal: shut down the engine, chock the wheels, connect the bond cable to the loading arm, ground the trailer, then open the dome slowly - and stay at the controls until the meter stops.