CDL Hazmat Test: What's on the H Endorsement Exam

The CDL hazmat test is the written knowledge test you must pass to get the H (hazardous materials) endorsement on your CDL. It covers how to identify hazardous materials, load them safely, placard your vehicle and transport the shipment.

Everything you need for the written test is in Section 9 of the CDL manual. The manual also calls it only a beginning. Most drivers need to know a lot more on the job.

What the hazmat endorsement test covers

The manual says you must know how to do four things:

• Identify what hazardous materials are.
• Safely load shipments.
• Properly placard your vehicle.
• Safely transport shipments.

The sections below cover each one.

The 9 hazard classes

A material's hazard class shows its risk. There are nine classes. This table uses the manual's Table 9.1 and one example it lists for each.

Learn the divisions too. Class 1 has six (1.1 mass explosion through 1.6 extremely insensitive). Class 2 has flammable, non-flammable and poisonous gases. Class 6 has poison and infectious substances.

Shipping papers

A shipping paper describes the hazardous material. Shipping orders, bills of lading and manifests all count.

The basic description goes in this order: identification number, proper shipping name, hazard class, and packing group. Expect a question on that order.

Know where the papers go. The manual says keep hazmat shipping papers:

• In a pouch on the driver's door, or
• In clear view and within reach while your seat belt is fastened, or
• On the driver's seat when you're out of the vehicle.

Keep them on top of other papers or tabbed, and keep the emergency response information in the same place. Shipping papers also list an emergency response phone number.

Placards basics

You attach placards before you drive. A placarded vehicle needs placards on the front, rear and both sides. The manual says each placard must be:

• Easy to see from the direction it faces.
• At least three inches away from any other marking.
• Kept clear of ladders, doors and tarps.
• Clean and undamaged.

Slogans like "Drive Safely" are prohibited.

The trap is the two placard tables. Table A materials need a placard for any amount. Table B materials need placards only when the total is 1,001 pounds or more, adding all Table B products on board. If INHALATION HAZARD is on the paper or package, you need the poison placard in addition to others, and the 1,000 pound exception does not apply.

Loading and segregation

Set the parking brake before loading or unloading. Don't use hooks. Brace packages so they can't move. Never transport a leaking package.

Know these classes:

• No smoking around Classes 1, 2.1, 3, 4 and 5 while loading or unloading.
• Cargo heater rules apply to Classes 1, 2.1 and 3.
• No overhang or tailgate loads of Classes 1, 4 and 5 unless packages are fire and water resistant, or covered with a fire and water resistant tarp.

Mixed loads are a favorite topic. Never load a package labeled POISON or POISON INHALATION HAZARD in the cab or sleeper, or with food for people or animals. The manual's Do Not Load table lists more combinations, so read it.

Driving and parking rules

These numbers come up a lot:

• Explosives (1.1, 1.2, 1.3): never park within five feet of the traveled part of the road. Don't park within 300 feet of a bridge, tunnel, building, place where people gather or open fire, except briefly for things like fueling.
• Attendant: in the vehicle and awake (not in the sleeper berth), or within 100 feet with the vehicle in clear view.
• Fire extinguisher: UL rating of 10 B:C or more on the power unit of a placarded vehicle.
• Railroad crossings: stop 15 to 50 feet before the nearest rail if you're placarded, carry any amount of chlorine, or have cargo tanks used for hazardous materials.
• Smoking: not within 25 feet of certain placarded vehicles and tanks.
• No flares. Use reflective triangles or red electric lights around Class 3 tanks, Division 2.1 tanks and Division 1.1, 1.2 or 1.3 loads.
• Turn the engine off when fueling, and keep someone at the nozzle.

Explosives (1.1, 1.2, 1.3) also need a written route plan.

Emergencies

At a crash, your job is to keep people away, limit the spread of material only if you can do it safely, and tell responders about the danger. Give them the shipping papers and emergency response information.

For a leak: don't touch it, and don't try to identify it by smell. If material is spilling, park it, secure the area, stay there and send someone else for help. The Emergency Response Guidebook (ERG) is indexed by proper shipping name and identification number.

For a fire, call for help. Feel the trailer doors before opening. If they're hot, don't open them.

The TSA background check

You also need to clear a TSA Security Threat Assessment. TSA's page says the program checks any driver seeking to obtain, renew or transfer a hazmat endorsement. TSA sends your eligibility result to your state, and the state issues the endorsement.

TSA recommends you enroll at least 60 days before you need an eligibility determination. Renewals count too. TSA also says you submit new fingerprints when you renew.

How to study it in a few days

Spend day 1 on the nine classes and the placard tables. Do shipping papers on day 2. Do loading, mixed loads and the Do Not Load table on day 3. Do parking distances and railroad crossings on day 4. Do emergencies on day 5, then take a timed practice test.

Missed questions show you what to reread. Not sure where you stand? Start with a free diagnostic.