Study guide
3.2 Bulk Packaging & Cargo Tanks
CDL HAZMAT Endorsement Exam
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1 Introduction & Exam Overview
1.1 Current Exam Facts 1.2 Getting the HazMat Endorsement 1.3 Why the Rules Exist: HMR & the Three Roles
2 Hazard Classes & the Communication Rule
2.1 The Nine Hazard Classes 2.2 The Hazardous Materials Table & Shipping Papers 2.3 Markings, Labels & Placards
3 Loading, Unloading & Safe Transport
3.1 Loading & Unloading Rules 3.2 Bulk Packaging & Cargo Tanks 3.3 Routes, Parking & Driving Rules
4 Emergencies & Incident Response
4.1 Using the Emergency Response Guidebook 4.2 Accidents, Spills & Fires 4.3 Incident Reporting & Security Plans
3.2 Bulk Packaging & Cargo Tanks
Key Takeaways Explain This Topic AI
A bulk package for a liquid has a maximum capacity greater than 119 gallons; non-bulk is 119 gallons or less.
A bulk package of any quantity of a Table 2 hazardous material must be placarded on all four sides — the 1,001-pound rule applies only to non-bulk packages.
A placarded cargo tank, or any vehicle carrying Division 1.1, 1.2, or 1.3 explosives, must never be left unattended.
A tanker driver must inspect the tank, valves, and fittings before loading and after unloading, plus normal pre-trip checks.
Cargo tanks must be inspected, tested, and marked on a federally required schedule, and flammable-liquid or gas tanks have extra grounding and venting precautions.
Last updated: May 2026
Bulk vs. Non-Bulk Packaging
The HazMat exam expects you to know whether a package is bulk or non-bulk , because that single classification changes the placarding, marking, and inspection rules.
Bulk packaging is a single container with no intermediate form of containment. A liquid bulk package has a maximum capacity greater than 119 gallons . Cargo tanks, portable tanks, large intermediate bulk containers (IBCs), and tank cars are bulk packages.
Non-bulk packaging is anything smaller — a liquid non-bulk package holds 119 gallons or less . Drums, boxes, jerricans, and cylinders are typical non-bulk packages.
- Package type Liquid capacity Solid capacity Examples
- Non-bulk 119 gallons or less 882 lb (400 kg) or less net mass Drums, boxes, cylinders
- Bulk Greater than 119 gallons Greater than 882 lb (400 kg) Cargo tanks, IBCs, portable tanks
- Why the Difference Matters for Placarding
For non-bulk Table 2 materials, placards are required only when the vehicle carries 1,001 pounds or more aggregate gross weight . For a bulk package, that threshold does not apply: a bulk package of any quantity of a placardable material must be placarded on all four sides of the vehicle. A 1,500-gallon cargo tank of gasoline is placarded FLAMMABLE even though no "1,001-pound" calculation was ever needed.
Cargo Tank Rules
A cargo tank is a bulk container permanently attached to (or forming part of) a vehicle. Cargo tanks carry fuels, gases, acids, and other liquids in large quantity, so the regulations are strict.
Key cargo-tank rules:
Placard all four sides for the material carried, regardless of quantity.
Qualified attendant required during loading/unloading. A person who understands the hazards and knows the emergency procedures must watch the operation, stay within 25 feet, and have a clear view of the tank.
Engine off during loading/unloading of flammable liquids unless the engine drives the transfer pump.
Inspect before loading and after unloading. The driver must inspect the tank shell, valves, fittings, manhole covers, and closures to confirm they are secure and not leaking.
Cargo tanks must be periodically tested and marked. Federal rules require visual inspections, pressure/leakage tests, and thickness tests on a set schedule; the test dates are stamped or marked on the tank's specification plate.
The Attendance Requirement
Certain loads can never be left unattended . A vehicle is "attended" when a person who is awake, not in the sleeper berth, and within 25 feet with an unobstructed view of the vehicle is in control of it.
Attendance is required for:
A placarded cargo tank during loading, unloading, and (with limited exceptions) while parked.
A vehicle carrying Division 1.1, 1.2, or 1.3 explosives , which must be attended at all times unless parked in an approved safe haven or a secure carrier/consignee facility.
The person attending must know the emergency procedures , be able to move the vehicle if needed, and have the equipment and knowledge to respond to a leak or fire.
Loading diagram... Cargo Tank Loading Sequence
Special Rules for Flammable-Liquid and Gas Tankers
Flammable liquids and compressed gases give off vapors that can ignite from a single spark, so tankers hauling them carry extra precautions.
Flammable-Liquid Tankers
Ground/bond the tank before and during loading of flammable liquids so static electricity cannot build up and arc into vapor.
No smoking within 25 feet , and shut the engine off during loading or unloading unless it powers the transfer pump.
Be alert to liquid surge — a partially full "baffled" or "unbaffled" tank lets liquid slosh, which can shove the vehicle forward at a stop. Brake early and smoothly.
Beware of the high center of gravity of a loaded tank; take curves and ramps well below the posted speed.
Compressed-Gas Tankers (Division 2.1 / 2.2)
Gas tanks operate under pressure; valves and relief devices must be checked and protected from damage.
Cargo heaters are prohibited with Division 2.1 flammable gas .
Some gases are also poison-inhalation hazards (for example, anhydrous ammonia) and carry both a gas placard and a poison/inhalation-hazard placard.
The core idea for the exam: a tanker is a single huge container, so a tank failure releases the entire load at once — which is why inspection, attendance, grounding, and smooth driving all matter more for tankers than for boxed freight.