Package Handling, Loading and Unloading, and Segregation Rules
Before you load
Inspect every package. Do not accept or load one that is leaking, stained, crushed, wet, or missing labels, and never open a package to check its contents. Load labeled packages so the labels are visible, brace and dunnage the load so nothing can shift, and never throw or drag a hazmat package. Keep shipping papers handy so you can answer questions at a shipper's dock. Do not smoke or carry a lit cigarette while loading or unloading, and never load hazmat where it can be struck by other freight or exposed to heat.
Segregation
The segregation table (49 CFR 177.848) uses an X to mean two classes may not be loaded together in the same vehicle. Beyond the table, learn the pairings that show up most: acids with cyanides or cyanide-bearing compounds (mixing produces deadly hydrogen cyanide gas), oxidizers with flammables, and Division 1.1 or 1.2 explosives with detonators or detonating cord. Poison-inhalation-hazard materials (6.1 PG I and 2.3) and other toxic materials must be kept away from food, feed, and anything intended for human or animal consumption. Never stack heavy hazmat on top of fragile packaging.
While unloading
Set the parking brake, chock the wheels, shut off the engine when flammables are involved, and stay with the hose or container - an unattended transfer is a violation and a common accident cause. Watch for spills at the connection point and know where the emergency shutoff is.
Rule of thumb
The segregation table is the legal minimum, but the physical rule is stronger: if two materials would react violently when they mix, a spill or wreck makes them mix - so they do not ride together.
Worked example
A driver is offered pallets of sodium cyanide and drums of hydrochloric acid. The segregation table gives an X for 6.1 with 8, and the chemistry confirms it. The driver refuses the second load rather than trying to separate them in the trailer.