Special Hazmat Cargo: Bulk Tanks, Cargo Tanks, Portable Tanks, and PIH Materials
What this domain covers
Bulk packaging, cargo tanks, portable tanks, and the extra rules for toxic-by-inhalation loads - the part of the test where equipment knowledge decides the answer.
Key definitions
A bulk packaging holds more than 119 gallons of liquid, more than 882 pounds of solid, or more than 1,000 pounds water capacity of gas. A cargo tank is a bulk packaging permanently attached to the vehicle. A portable tank is a bulk packaging not permanently attached, marked with a UN number and a tank instruction (UN31A, UN31T, IMO 1).
Matching tank to cargo
- DOT/MC-306, 406, 407 - low-pressure tanks for flammable liquids and corrosives.
- MC-331 - high-pressure tanks for propane and anhydrous ammonia.
- MC-338 - insulated cryogenic tanks for liquid oxygen or nitrogen.
- A corrosive may not ride in a tank built only for petroleum; the specification and lining must match the cargo.
Tank inspections
Cargo tanks get an external visual inspection and leak test at least annually, plus an internal inspection and pressure test at least every five years (49 CFR 180.407). The specification plate and test dates must be current.
Unloading
Set the parking brake, chock the wheels, shut the engine off, no smoking, attend the entire transfer, ground and bond for flammable liquids, check hoses and valves before opening, and close and cap everything before pulling away. Never leave an unloading tank unattended.
PIH loads
Placard Division 2.3 and Division 6.1 Hazard Zone A/B material as toxic, segregate it from food and feed, keep emergency response information with the shipping paper, and route away from populated areas and tunnels.
Worked example
A 1,500-gallon tanker of flammable liquid is a bulk packaging, so the UN number and proper shipping name are marked on the tank; the annual inspection and five-year pressure test must be in date; at the terminal the wheels are chocked and the driver stays at the transfer.
Traps
Treating a 500-gallon portable tank as non-bulk; leaving the truck to sign paperwork during a transfer; and assuming any tanker can haul any liquid.