Loading, Unloading, Segregation and Cargo Securement
Before loading
Match the shipping paper against the packages and inspect each one for leaks, damaged closures and required labels. Park on level ground, set the parking brake, chock the wheels and, for flammable liquids, shut off the engine unless it drives the pump. Keep smoking materials, flames and sparks at least 25 feet away.
Segregation
49 CFR 177.848 prohibits loading certain materials together. The pairings tested most often: cyanides and acids, oxidizers (5.1) with flammable liquids or solids, organic peroxides with combustibles, and explosives of incompatible compatibility groups. Poisons (6.1) must not be loaded with food, feed or other edible products, and radioactive materials follow their own separation table. Where a barrier is required, separate the loads with a bulkhead or an intervening load.
Securement and handling
Cargo must not shift: use dunnage, blocking and tiedowns, and never place hazmat in the cab, sleeper berth or passenger area. Load and unload with proper equipment - hand trucks, drum grapples, lift gates - and never drop, roll or drag packages. Bond and ground metal containers when transferring flammable liquids so static electricity cannot ignite vapor. Keep the loading area clear and stay with the vehicle.
Worked example
A load offers nitric acid (Class 8, subsidiary 5.1) and sodium cyanide (6.1). Cyanides must never be loaded with acids; mixing them can release hydrogen cyanide gas. The correct answer is a separating barrier or separate vehicles, and the acid's 5.1 subsidiary is a second reason to keep it away from flammables and combustibles.
Traps
Assuming segregation applies only to explosives; forgetting the food rule for poisons; laying drums on their sides without blocking; and leaving the engine running during a flammable liquid transfer.