20 HazMat Endorsement (H) Practice Questions & Answers

1. 1. The federal Hazardous Materials Regulations are built around three basic intents. Which set states them correctly?

   • A.Limit the weight, limit the speed, and limit the route
   • B.Train the shipper, license the carrier, and tax the hazardous cargo
   • C.Insure the shipment, inspect the vehicle, and inventory the cargo
   • D.Contain the product, communicate the risk, and ensure safe drivers and equipment✓ Answer

   The HMR (49 CFR Parts 100-185) exist to contain the product so it cannot escape its packaging, to communicate the risk through shipping papers, markings, labels and placards, and to assure safe drivers and equipment through training, testing and vehicle rules. Every other requirement in the manual — packaging, paperwork, placards, parking and route rules — traces back to one of these three intents.

   Source: AAMVA Model CDL Manual 9.1.1 (Intent of the Regulations); 49 CFR Parts 100-185Report a problem with this question

2. 2. Which material-to-hazard-class pairing is correct?

   • A.Propane — Division 2.2, Non-Flammable Gas
   • B.Battery fluid (acid) — Class 9, Miscellaneous
   • C.Sodium — Division 4.3, Dangerous When Wet✓ Answer
   • D.Ammonium nitrate — Division 5.2, Organic Peroxide

   Sodium reacts with water and gives off flammable hydrogen gas, which is exactly the hazard that defines Division 4.3, Dangerous When Wet. The other pairings are wrong: propane is Division 2.1 (flammable gas), ammonium nitrate is Division 5.1 (oxidizer), and battery fluid is Class 8 (corrosive).

   Source: 49 CFR 172.101 Hazardous Materials Table; AAMVA Model CDL Manual 9.2.1 (Hazard Classes)Report a problem with this question

3. 3. Your trailer holds 800 pounds of a Class 3 flammable liquid in non-bulk drums and no other hazardous material. What placards are required?

   • A.FLAMMABLE placards on all four sides
   • B.None — Class 3 is a Table 2 material and the load is under 1,001 pounds✓ Answer
   • C.A FLAMMABLE placard on the rear only
   • D.DANGEROUS placards on all four sides

   Class 3 appears in Table 2 of 49 CFR 172.504, so placards are required only when the aggregate gross weight of all Table 2 hazardous materials aboard reaches 1,001 pounds. At 800 pounds in non-bulk packaging no placard is required — but the same 800 pounds of a Table 1 material such as Division 2.3 poison gas or 4.3, or any bulk package, would have to be placarded.

   Source: 49 CFR 172.504(c) and Table 2; AAMVA Model CDL Manual 9.4.2 (Placarding Tables)Report a problem with this question

4. 4. You are hauling 100 pounds of a Division 4.3 (dangerous when wet) material and nothing else hazardous. Must the vehicle be placarded?

   • A.Yes, but only the DANGEROUS placard may be used
   • B.Yes — 4.3 is a Table 1 material, which must be placarded in any amount✓ Answer
   • C.No — the load is far below the 1,001-pound aggregate
   • D.No — placards are required only for bulk packages

   Division 4.3 is listed in Table 1 of 49 CFR 172.504(e), and Table 1 materials must be placarded in any amount, so the 1,001-pound aggregate rule never applies to them. Because the vehicle is now placarded, it must also stop 15 to 50 feet from the nearest rail at railroad crossings.

   Source: 49 CFR 172.504(e) Table 1; 49 CFR 392.10(a)(3); AAMVA Model CDL Manual 9.4.2Report a problem with this question

5. 5. When may a driver use the DANGEROUS placard?

   • A.When 1,001 pounds or more of two or more Table 2 classes are aboard — but not if 2,205 pounds or more of any one of those classes was loaded at a single facility✓ Answer
   • B.Any time the load contains hazardous material, as a substitute for class placards
   • C.Only when the shipper failed to supply the specific placards
   • D.Never — DANGEROUS is not a legal placard

   DANGEROUS is always an option and never a requirement: 49 CFR 172.504(b) allows it in place of separate placards when 1,001 pounds or more of two or more Table 2 classes are on board, but if 2,205 pounds (1,000 kg) or more of any one of those classes was loaded at a single facility, that class must show its own placard so responders know exactly what dominates the load.

   Source: 49 CFR 172.504(b); AAMVA Model CDL Manual 9.4.3 (DANGEROUS Placard)Report a problem with this question

6. 6. A placarded load must display placards where, and how many?

   • A.One on the front of the tractor is enough
   • B.On the rear and the driver's side only
   • C.On all four sides — front, rear and both sides — at least four identical placards✓ Answer
   • D.On both sides only

   49 CFR 172.516 requires placards on the front, rear and both sides — at least four identical placards — so the hazard can be identified from whatever direction a responder approaches. The front placard may be on the tractor or the trailer, and each placard must read left to right, sit at least 3 inches from other markings on a contrasting background, and show the class or division number in the lower corner.

   Source: 49 CFR 172.516 (Visibility and display of placards); AAMVA Model CDL Manual 9.4.1Report a problem with this question

7. 7. A shipping paper shows 200 pounds of a Division 6.1 material with the words "Inhalation Hazard." What placarding applies?

   • A.Class 6 placards only if the material is in a bulk package
   • B.DANGEROUS placards only
   • C.None — the amount is under 1,001 pounds
   • D.POISON INHALATION HAZARD (or POISON GAS) placards in addition to any other required placards — the 1,001-pound rule does not apply✓ Answer

   When "Inhalation Hazard" appears on the shipping paper or package, 49 CFR 172.505 requires POISON INHALATION HAZARD or POISON GAS placards in addition to any other placards the load needs, with no 1,001-pound exception, because even a small release of a PIH material can be lethal downwind. The same no-threshold logic applies to a subsidiary DANGEROUS WHEN WET hazard.

   Source: 49 CFR 172.505 (Placarding for subsidiary hazards); AAMVA Model CDL Manual 9.4.5Report a problem with this question

8. 8. On a shipping paper, the basic description of a hazardous material must appear in which order?

   • A.Identification number, proper shipping name, hazard class or division, packing group✓ Answer
   • B.Hazard class, identification number, proper shipping name, packing group
   • C.Packing group, hazard class, proper shipping name, identification number
   • D.Proper shipping name, packing group, identification number, hazard class

   49 CFR 172.202(b) fixes the sequence as identification number, proper shipping name, hazard class or division, then packing group — for example "UN1263, Paint, 3, PG II" — so that anyone reading the paper finds the same four elements in the same place every time. Nothing in the basic description may be abbreviated unless authorized, although the packaging type and unit of measure may be ("10 ctns., 500 lbs").

   Source: 49 CFR 172.202(b) (Description of hazardous material); AAMVA Model CDL Manual 9.3.1Report a problem with this question

9. 9. A shipping paper lists both hazardous and non-hazardous freight. How may the hazardous entries be identified?

   • A.The driver must circle them in red before leaving
   • B.Entered first, or highlighted in a contrasting color, or marked with an "X" (or "RQ") in a column captioned "HM"✓ Answer
   • C.They must be on a separate page from all other freight
   • D.They must be typed entirely in capital letters

   49 CFR 172.201(a) gives exactly three ways to make hazmat stand out on a mixed shipping paper: list the hazardous entries first, highlight them in a contrasting color, or put an "X" — or "RQ" for a reportable quantity — in a column captioned "HM". The point is that an emergency responder can find the hazardous items instantly instead of reading an entire manifest.

   Source: 49 CFR 172.201(a) (Preparation of shipping papers); AAMVA Model CDL Manual 9.3.2Report a problem with this question

10. 10. Where must the shipping papers and emergency response information for a hazmat load be kept?

    • A.In a pouch on the driver's door or in clear view within immediate reach while driving, and on the driver's seat when the driver is out of the vehicle✓ Answer
    • B.In the trailer with the freight
    • C.Mailed ahead to the consignee; no copy is needed in the cab
    • D.Locked in the glove box at all times

    Under 49 CFR 177.817(e) the papers must be in a pouch on the driver's door or in clear view within immediate reach with the seat belt fastened while driving, and on the driver's seat when the driver leaves the vehicle, so rescuers can find them even if the driver is unconscious or absent. Emergency response information must be kept with the shipping papers, and the hazmat entries must be tabbed or placed on top of the stack.

    Source: 49 CFR 177.817(e) and 172.602(b); AAMVA Model CDL Manual 9.3.5 (Papers in the Vehicle)Report a problem with this question

11. 11. Column 3 of the Hazardous Materials Table shows "Forbidden" for a material. What does that mean?

    • A.It may be transported only if the vehicle displays DANGEROUS placards
    • B.It may never be transported✓ Answer
    • C.It is forbidden by air but allowed by highway
    • D.It may be shipped only under a special permit

    "Forbidden" in Column 3 means the material is too dangerous to move at all — no packaging, permit or placard makes it legal, and a driver must never accept such a shipment. Column 3 otherwise gives the hazard class or division, while Column 1 symbols such as (A), (W), (D), (I) and (G) tell you when an entry applies only to air, water, domestic or international shipments, or requires a technical name.

    Source: 49 CFR 172.101 Column 3 and 49 CFR 173.21 (Forbidden materials); AAMVA Model CDL Manual 9.2.2Report a problem with this question

12. 12. Who marks a package with the proper shipping name and identification number and applies the diamond hazard labels, and what is the driver's related duty?

    • A.No marking is needed as long as the vehicle is placarded
    • B.The shipper marks and labels the package; the driver compares markings and labels against the shipping paper and refuses any leaking package✓ Answer
    • C.The carrier's dispatcher marks the packages; the driver only signs for them
    • D.The driver marks and labels the packages at the dock

    Marking and labeling are the shipper's responsibility under 49 CFR Part 172 Subparts D and E: the package must show the proper shipping name and ID number plus a diamond-shaped hazard label, attached to a tag when the package (such as a cylinder) is too small. The driver's job is to verify that the markings and labels match the shipping paper and to refuse leaking packages, because it is illegal to transport a package that is leaking.

    Source: 49 CFR 172.301, 172.400 and 177.801; AAMVA Model CDL Manual 9.3.6 (Package Markings and Labels)Report a problem with this question

13. 13. The floor of a cargo space carrying Division 1.1, 1.2 or 1.3 explosives must be lined with what?

    • A.Non-metallic material or non-ferrous metal✓ Answer
    • B.Stainless steel at least 1/8 inch thick
    • C.Any smooth metal that can be swept clean
    • D.No lining is needed as long as the packages are braced

    49 CFR 177.835(c) requires the cargo floor for Division 1.1, 1.2 or 1.3 explosives to be tight and lined with non-metallic material or non-ferrous metal, because steel and other ferrous metals can throw a spark when struck by grit or shifting freight. Stainless steel is still a ferrous metal, so it does not satisfy the rule.

    Source: 49 CFR 177.835(c) (Class 1 materials); AAMVA Model CDL Manual 9.5.2 (Loading Explosives)Report a problem with this question

14. 14. You are loading Division 6.1 poison packages. Which statement is correct?

    • A.They may ride in the sleeper berth if they are secured
    • B.They may be loaded with foodstuffs if separated by at least 4 feet
    • C.They may never be carried in the cab or sleeper, and never loaded with human or animal foodstuffs unless over-packed in an authorized way✓ Answer
    • D.The foodstuff restriction applies only to Division 2.3 poison gases

    49 CFR 177.841 bars Division 6.1 and 2.3 materials from the driver's cab or sleeper and prohibits loading them with human or animal foodstuffs unless the poison is over-packed in an approved manner, because contamination of food is the specific hazard the rule guards against. Mouthwash, toothpaste and skin cream are not treated as foodstuffs.

    Source: 49 CFR 177.841(e) (Poisons); AAMVA Model CDL Manual 9.5.3 (Poison Loading Rules)Report a problem with this question

15. 15. A placarded vehicle parked on a public roadway must be attended. A person is "attending" the vehicle when that person is:

    • A.Within 100 feet with the vehicle in clear view, awake and not in the sleeper berth, and able to move it✓ Answer
    • B.Anywhere on the property as long as the alarm can be heard
    • C.Within 300 feet of the vehicle
    • D.Asleep in the sleeper berth of that vehicle

    49 CFR 397.5(d) defines attendance as being in the vehicle (awake, and not in the sleeper berth) or within 100 feet with an unobstructed view of it, while knowing the hazards of the material, knowing the emergency procedures, and being authorized and able to move the vehicle. Keep the distances straight: 100 feet is attendance, 25 feet is the cargo-tank attendant limit and the no-smoking radius, 5 feet is the parking setback from the traveled roadway, and 300 feet is the explosives standoff.

    Source: 49 CFR 397.5(d) (Attendance and surveillance); AAMVA Model CDL Manual 9.6.2Report a problem with this question

16. 16. You are driving a cargo tank that last carried a hazardous material but is now empty. Must you stop at railroad crossings?

    • A.Yes — stop 5 to 15 feet from the nearest rail
    • B.Only at crossings with no gates or lights
    • C.No — an empty tank is exempt from the stop
    • D.Yes — stop 15 to 50 feet from the nearest rail; cargo tanks used for hazardous materials require the stop whether loaded or empty✓ Answer

    49 CFR 392.10 requires a stop 15 to 50 feet from the nearest rail for placarded vehicles, for any vehicle carrying any amount of chlorine, and for cargo tanks used for hazardous materials whether loaded or empty, because residue and vapor left in an "empty" tank are still hazardous. Do not shift gears while crossing the tracks.

    Source: 49 CFR 392.10(a)(3)-(4) (Railroad grade crossings); AAMVA Model CDL Manual 9.6.3Report a problem with this question

17. 17. How often must the driver of a placarded vehicle examine the tires?

    • A.Once a day, before the first trip only
    • B.Every 2 hours or 100 miles, whichever comes first
    • C.Only at the end of each trip
    • D.At the beginning of each trip and each time the vehicle is parked✓ Answer

    49 CFR 397.17 requires the driver to examine each tire at the beginning of each trip and each time the vehicle is parked, because an overheating or under-inflated tire is a common ignition source under a hazmat load. The only acceptable way to check inflation is a tire pressure gauge; a leaking or flat tire may be driven on only as far as the nearest safe place to repair it, and an overheated tire must be removed and placed a safe distance from the vehicle.

    Source: 49 CFR 397.17 (Tires); AAMVA Model CDL Manual 9.6.4Report a problem with this question

18. 18. At a truck stop you discover a package in your trailer leaking a hazardous material. What should you do?

    • A.Keep driving to the next town to find a telephone
    • B.Smell the material to identify it, then decide what to do
    • C.Repack the material and continue the trip
    • D.Park the vehicle, secure the area, stay with it, and send someone else for help with the shipping name, hazard class and ID number✓ Answer

    49 CFR 177.854 and the manual's leak rules say never to move away from a leaking vehicle, never to touch or smell the material, and never to repack it — driving on only spreads contamination along the road. Park it, secure the area, stay there, and send someone else with the exact location, your carrier and terminal information and the shipping name, class and ID number, since responders look the material up in the Emergency Response Guidebook by proper shipping name or ID number.

    Source: 49 CFR 177.854 (Disabled vehicles and broken packages); 49 CFR 172.602; AAMVA Model CDL Manual 9.7.2Report a problem with this question

19. 19. Which situation requires an immediate telephone notice to the National Response Center at (800) 424-8802?

    • A.The load will arrive several hours late
    • B.The driver forgot to tab the shipping papers
    • C.A placard blows off the trailer during the trip
    • D.A person is hospitalized as a direct result of the hazardous material✓ Answer

    49 CFR 171.15 requires immediate telephone notice to the NRC when, as a direct result of a hazardous material, someone is killed or requires hospitalization, the public is evacuated for an hour or more, a major transportation artery or facility is closed for an hour or more, fire, breakage, spillage or suspected radioactive contamination occurs, or a continuing danger to life exists. The carrier must also file a detailed written report afterward; CHEMTREC at (800) 424-9300 is a 24-hour technical information line, not a substitute for the required government notification.

    Source: 49 CFR 171.15 (Immediate notice of certain hazardous materials incidents); AAMVA Model CDL Manual 9.7.3Report a problem with this question

20. 20. Before a state may issue a hazardous materials (H) endorsement, the applicant must:

    • A.Obtain a letter of sponsorship from a shipper
    • B.Own or lease a placarded vehicle
    • C.Only pass the hazardous materials knowledge test
    • D.Pass a TSA security threat assessment, including fingerprinting and criminal-history and immigration records checks✓ Answer

    49 CFR 383.71(a) and 49 CFR Part 1572 make a TSA security threat assessment — fingerprints plus criminal history, immigration status and mental-capacity records checks — a condition the state must confirm before issuing or renewing the H endorsement, so passing the knowledge test alone is not enough. A driver who is later convicted or indicted for a disqualifying offense must surrender the endorsement, and all hazmat employees must also receive security awareness training.

    Source: 49 CFR 383.71(a)(2) and 49 CFR Part 1572 (TSA security threat assessment); AAMVA Model CDL Manual 9.1.3Report a problem with this question

Practice questions based on the AAMVA/FMCSA model CDL manual. Requirements vary by state — study your state's official CDL manual before your exam. Official CDL info →