Loading, Unloading, Segregation, and Securement of Hazardous Materials
This domain is about the dock. The exam tests securement, the basic loading rules, and segregation - which materials may never ride together regardless of how well they are braced.
Securement and basic loading rules (section 177.834)
- Packages must be blocked, braced, or tied down so they cannot shift in transit.
- No smoking during loading or unloading.
- Engine off, parking brake set, wheels chocked where needed.
- A qualified person must attend the vehicle during loading and unloading of most hazmat, and the cargo area must not be left open and unattended.
- Never use hooks, and never drop, drag, or roll packages that are marked as fragile or that carry liquid hazard labels.
Segregation (sections 177.848 and 177.841)
The segregation table marks prohibited pairs with an X. Classic combinations:
- Division 1.1 and 1.2 detonators with other explosives, except as the table permits.
- Cyanides or sulfide-bearing material with acids.
- Division 6.1 PG I poisons, and Division 2.3 poison inhalation hazards, with foodstuffs or animal feed - prohibited outright.
- Radioactive materials with food only under the conditions in section 177.841.
Worked example
Bagged flour sits on the dock beside a case of Division 6.1 PG I pesticide. They may not be loaded on the same vehicle. Bracing them at opposite ends of the trailer does not cure the problem, because the segregation rule bars the combination entirely.
Traps
Treating segregation as a rule for bulk packages only; assuming any two non-explosive materials are compatible; forgetting that poor securement is a violation even when the load is light; leaving a placarded vehicle unattended and open at the dock.