DMV Practice LabChange state
COColorado
DMV Practice LabAll tests

Colorado hazardous materials practice

Selected knowledge practice, not a complete licensing course or practical training.

Colorado CDL Hazardous Materials

Practice mode
Question 1 of 80
  1. 1. Why do hazardous-material transportation rules address both packaging and hazard communication?
  2. 2. Who normally classifies a shipment and supplies its proper shipping description before the carrier accepts it?
  3. 3. A hazardous-material package is visibly leaking at pickup. What should the driver do?
  4. 4. A driver subject to ELDT is applying for an H endorsement for the first time. When must the required theory training be completed?
  5. 5. Under the general federal hazmat-employee training rule, how often is recurrent training required?
  6. 6. A newly hired hazmat employee has not finished required initial training. What condition permits covered work during the initial training period?
  7. 7. After a hazmat employee leaves that role with an employer, how long must that employer keep the required current training record?
  8. 8. Which subject belongs in a hazmat driver's security-awareness training?
  9. 9. For an ordinary highway shipment assigned a packing group, which basic-description order is correct?
  10. 10. Hazardous and nonhazardous freight appear on one shipping paper. Which is an accepted way to identify the hazardous entries?
  11. 11. What language must the required hazardous-material shipping description use for covered U.S. transportation?
  12. 12. Which abbreviation is expressly allowed in the shipping-paper rules when it is commonly accepted and recognizable?
  13. 13. A required shipping paper spans three pages. How should the pages be identified?
  14. 14. Where may the total quantity appear relative to the basic hazardous-material description?
  15. 15. When a subsidiary hazard class must be shown on a shipping paper, where is its number entered?
  16. 16. A material's table entry has no assigned packing group. Should the driver invent a packing group to fill the description?
  17. 17. A required emergency-response number goes to a machine asking callers to wait for a callback. Is that sufficient?
  18. 18. A shipper uses an outside emergency-response telephone service. What associated identification must appear as prescribed on the paper?
  19. 19. Can emergency-response information be kept in a separate guidance document?
  20. 20. Which information must be included in the required emergency-response information?
  21. 21. You are at the truck's controls with your lap belt fastened. Where must the required shipping paper be?
  22. 22. Before leaving the controls of a truck carrying a covered hazardous shipment, where may you leave its required shipping paper?
  23. 23. Required hazardous-material papers are carried with other paperwork. How should the driver distinguish them?
  24. 24. For a non-waste hazardous-material shipment, how long must a receiving motor carrier retain the required shipping-paper copy?
  25. 25. A shipment's paperwork looks correct, but required hazard markings are missing from its packages. What should the driver do?
  26. 26. What does a material's hazard class communicate?
  27. 27. What is the purpose of the four-digit UN or NA identification number associated with a hazardous shipment?
  28. 28. Which Hazardous Materials Table column gives the proper shipping name?
  29. 29. Where does the Hazardous Materials Table identify required hazard labels?
  30. 30. Absent an applicable exception, where must required placards be displayed on a transport vehicle containing hazardous materials?
  31. 31. A highway shipment contains 200 pounds of Division 4.3 material with no applicable exception. Does being below 1,001 pounds remove its placarding requirement?
  32. 32. A truck carries 900 pounds aggregate gross weight of ordinary Class 3 material in non-bulk packages. No subsidiary-hazard or other special requirement applies. What does 172.504(c) permit?
  33. 33. When applying the Table 2 aggregate gross-weight placarding threshold, does packaging weight count?
  34. 34. Can a bulk package rely on the general less-than-1,001-pound Table 2 placarding exception merely because it contains little material?
  35. 35. A vehicle carries qualifying non-bulk packages from two Table 2 categories requiring different placards. Neither category reaches 2,205 pounds loaded at one facility. Which option may be available?
  36. 36. A qualifying mixed non-bulk load uses DANGEROUS placards. One facility loads 2,300 pounds aggregate gross weight of Class 8 material. What additional category display is required?
  37. 37. For a domestic Class 9 shipment in bulk packaging, what is true even though a CLASS 9 placard is not required?
  38. 38. A required placard is partly hidden behind a ladder. What is the appropriate correction?
  39. 39. How far must a placard be from advertising or other markings that could reduce its effectiveness?
  40. 40. For a tractor and cargo body, may the required front placard be displayed on the front of the truck-tractor?
  41. 41. Hazardous-material packages are not permanently attached to the vehicle. What must their securement prevent during normal transportation?
  42. 42. A package bears required orientation arrows. How must it be carried?
  43. 43. Before loading or unloading hazardous material, what must be done to prevent the vehicle from moving?
  44. 44. A tool could damage a hazardous package's closure during unloading. Should it be used?
  45. 45. A cargo-tank unloading operation uses the ordinary in-person attendance method, with no special exception or alternative system. How close must the qualified person remain?
  46. 46. For ordinary in-person cargo-tank attendance, which person is qualified?
  47. 47. An approved remote cargo-tank monitoring system loses its monitoring capability during transfer. What must happen?
  48. 48. An ordinary hazardous-liquid cargo tank still contains product. One manhole is unsecured. May it be driven a short distance to the exit?
  49. 49. Two hazardous products each have correct papers. What else must be checked before placing them together in the same cargo space?
  50. 50. A visitor wants to smoke next to a truck being unloaded with Class 3 flammable liquid. What should the driver do?
  51. 51. A placarded vehicle requires attendance. The attendant is outside, 80 feet away, but a building blocks the view. Does this meet the attendance definition?
  52. 52. A placarded vehicle needs an attendant. Does a driver asleep in the sleeper berth satisfy the rule?
  53. 53. What makes a parking area a safe haven for unattended Division 1.1, 1.2 or 1.3 loads?
  54. 54. A truck containing Division 1.2 material is parked four feet from the traveled part of a public highway. Is this allowed under the parking rule?
  55. 55. A driver of a placarded Class 3 vehicle wants to park within five feet of the traveled roadway for personal shopping. Does the brief operational-necessity exception cover that stop?
  56. 56. A Division 1.1 vehicle is to be parked 200 feet from a dwelling, with no qualifying operational necessity. Is that within the prohibited zone?
  57. 57. Before parking a Division 1.3 vehicle on private property, what must the person in charge of that property know and provide?
  58. 58. How close may a vehicle carrying covered hazardous materials be parked to an open fire under 397.11?
  59. 59. A placarded truck contains Class 3 flammable liquid. Someone stands 15 feet away with a lit cigarette. Is that far enough under the smoking rule?
  60. 60. An empty tank vehicle previously carried placard-required Class 3 flammable liquid. Does emptying the liquid by itself remove the 25-foot smoking restriction?
  61. 61. A truck containing covered hazardous materials stops to refuel its own fuel tank. What does the hazmat fueling rule require?
  62. 62. A normal truck power unit carries hazardous materials in a quantity requiring placards. What is its minimum required extinguisher rating?
  63. 63. An empty cargo tank used for Class 3 flammable-liquid transportation breaks down. Which warning equipment is appropriate to carry?
  64. 64. When does the tire rule for covered hazardous-material vehicles require examination of each tire?
  65. 65. A covered hazmat truck has a flat tire. Where may it be driven under the repair-location exception?
  66. 66. A tire on a covered hazmat vehicle is found overheated. What must be resolved before further operation?
  67. 67. A Class 3 placard-required truck approaches an ordinary railroad grade crossing with no applicable exception. Where must it stop?
  68. 68. A cargo tank formerly used to transport hazardous material is empty. At an ordinary grade crossing with no applicable exception, does empty status alone remove the federal stop requirement?
  69. 69. After making a required railroad stop, how should the driver choose a gear for crossing?
  70. 70. Which shipping information helps responders locate the appropriate entry in the Emergency Response Guidebook?
  71. 71. You notice an unfamiliar leak from hazardous cargo. How should you identify the material without deliberately exposing yourself?
  72. 72. Hazardous cargo is leaking and the driver wants to continue to a truck stop to find help. What is the appropriate response?
  73. 73. Hazardous cargo is burning and the driver lacks specialized firefighting training and equipment. What should the driver do?
  74. 74. While waiting for responders at a hazardous-material release, which location does the handbook recommend for people kept away from the scene?
  75. 75. What information is especially useful when someone contacts responders about your hazardous-cargo incident?
  76. 76. A transportation incident meets 171.15's NRC telephone-report criteria. When must the person in physical possession notify the NRC?
  77. 77. A hazardous material directly causes the public to be evacuated for exactly one hour. Does this meet the evacuation trigger for NRC telephone reporting?
  78. 78. A hazardous material directly causes an injury requiring admission to a hospital during transportation. Does that meet an NRC telephone-report trigger?
  79. 79. After an incident covered by 171.16, what is the ordinary deadline for the detailed hazardous-material incident report?
  80. 80. At pickup, a Division 6.2 package is damaged and appears to be leaking. What should the driver do?
Review all 80 questions with answers

  1. Why do hazardous-material transportation rules address both packaging and hazard communication?

    Correct answer: Packages contain the material; markings and papers communicate its hazards.

    A safe package helps prevent release. Accurate descriptions, labels, markings and placards help workers and responders recognize the hazards.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.1–9.2, physical PDF page 91. Reviewed September 14, 2026. ↗

  2. Who normally classifies a shipment and supplies its proper shipping description before the carrier accepts it?

    Correct answer: The shipper offering the material.

    The shipper identifies the material and prepares the required packaging and hazard communication. Carrier and driver checks remain necessary.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.2.1, physical PDF page 91. Reviewed September 14, 2026. ↗

  3. A hazardous-material package is visibly leaking at pickup. What should the driver do?

    Correct answer: Refuse it and have the problem resolved before transport.

    The handbook directs carriers and drivers to refuse leaking or improperly prepared shipments. A short trip does not make a leaking package safe.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.2.2–9.2.3, physical PDF page 91. Reviewed September 14, 2026. ↗

  4. A driver subject to ELDT is applying for an H endorsement for the first time. When must the required theory training be completed?

    Correct answer: Before the state H knowledge test.

    FMCSA requires applicable H theory training through a registered provider before the state administers the H knowledge test. This practice quiz is not registered ELDT.

    Source: FMCSA TPR FAQ, required training and H-endorsement row. Reviewed September 14, 2026. ↗

  5. Under the general federal hazmat-employee training rule, how often is recurrent training required?

    Correct answer: At least once every three years.

    49 CFR 172.704(c)(2) requires recurrent training at least every three years. A revised security plan can create an earlier in-depth security-training deadline.

    Source: 49 CFR 172.704(c)(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  6. A newly hired hazmat employee has not finished required initial training. What condition permits covered work during the initial training period?

    Correct answer: Direct supervision by a properly trained, knowledgeable hazmat employee.

    Initial training must be completed within 90 days, and covered functions performed beforehand must be under the specified direct supervision. This does not waive separate driver licensing requirements.

    Source: 49 CFR 172.704(c)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  7. After a hazmat employee leaves that role with an employer, how long must that employer keep the required current training record?

    Correct answer: For 90 days after employment as a hazmat employee ends.

    The employer retains current training records, inclusive of the preceding three years, throughout hazmat employment and for 90 days thereafter.

    Source: 49 CFR 172.704(d). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  8. Which subject belongs in a hazmat driver's security-awareness training?

    Correct answer: Recognizing and responding to possible transportation security threats.

    Security awareness covers transportation risks and ways to enhance security. Employees covered by a required security plan also need the applicable in-depth training.

    Source: 49 CFR 172.704(a)(4)–(5). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  9. For an ordinary highway shipment assigned a packing group, which basic-description order is correct?

    Correct answer: Identification number, proper shipping name, hazard class, packing group.

    The four basic elements must appear in the prescribed sequence, without unrelated information inserted between them. Authorized technical names and subsidiary hazards follow their specific rules.

    Source: 49 CFR 172.202(a)(1)–(4), (b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  10. Hazardous and nonhazardous freight appear on one shipping paper. Which is an accepted way to identify the hazardous entries?

    Correct answer: Put an X before their basic descriptions in an HM column.

    Other permitted methods include entering hazardous descriptions first or using the specified contrasting presentation. RQ may replace X when appropriate.

    Source: 49 CFR 172.201(a)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  11. What language must the required hazardous-material shipping description use for covered U.S. transportation?

    Correct answer: Legible English.

    The required shipping description and transport copies must be legible and printed manually or mechanically in English.

    Source: 49 CFR 172.201(a)(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  12. Which abbreviation is expressly allowed in the shipping-paper rules when it is commonly accepted and recognizable?

    Correct answer: A packaging-type abbreviation such as cyl. for cylinder.

    Commonly recognized packaging-type abbreviations and measurement units can be used. This does not authorize improvised abbreviations in the required material description.

    Source: 49 CFR 172.202(a)(7), (c)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  13. A required shipping paper spans three pages. How should the pages be identified?

    Correct answer: Number them consecutively and show the total on page one.

    Each page must be consecutively numbered, and the first must indicate the total, such as page 1 of 3.

    Source: 49 CFR 172.201(c). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  14. Where may the total quantity appear relative to the basic hazardous-material description?

    Correct answer: Before or after the basic description.

    Quantity and packaging information can appear before or after the basic description. They must not interrupt its prescribed sequence.

    Source: 49 CFR 172.202(b), (c)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  15. When a subsidiary hazard class must be shown on a shipping paper, where is its number entered?

    Correct answer: In parentheses immediately after the primary hazard class.

    Required subsidiary hazard numbers follow the primary class in parentheses. The rule includes exceptions when a corresponding subsidiary label is not required.

    Source: 49 CFR 172.202(a)(3). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  16. A material's table entry has no assigned packing group. Should the driver invent a packing group to fill the description?

    Correct answer: No; apply the entry's requirements without inventing one.

    Packing groups are shown when assigned and required. The rules specifically except entries with no assigned group and several named categories.

    Source: 49 CFR 172.202(a)(4). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  17. A required emergency-response number goes to a machine asking callers to wait for a callback. Is that sufficient?

    Correct answer: No; it must provide the required immediate knowledgeable access.

    The number must be monitored throughout transportation, including incidental storage. A callback-based answering service does not satisfy 172.604(a)(2).

    Source: 49 CFR 172.604(a)(1)–(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  18. A shipper uses an outside emergency-response telephone service. What associated identification must appear as prescribed on the paper?

    Correct answer: The registered person's name or assigned contract or unique identifier.

    The provider needs to link the call to the registered person's current shipment information. Placement and prominent-identification alternatives are specified in the rule.

    Source: 49 CFR 172.604(b)(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  19. Can emergency-response information be kept in a separate guidance document?

    Correct answer: Yes, if it is properly cross-referenced to the shipment description.

    A separate document is allowed when the shipping description is cross-referenced to the correct emergency information. A guide for an unrelated material is not enough.

    Source: 49 CFR 172.602(b)(3)(iii). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  20. Which information must be included in the required emergency-response information?

    Correct answer: Health hazards, fire risks and preliminary first-aid measures.

    The required information also includes the material description, immediate precautions, and initial methods for fires, spills and leaks. It must be immediately accessible for an incident.

    Source: 49 CFR 172.602(a), (c). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  21. You are at the truck's controls with your lap belt fastened. Where must the required shipping paper be?

    Correct answer: Within immediate reach and visible or in the driver's door holder.

    Both requirements matter: immediate reach while belted, plus visibility to someone entering the cab or storage in the specified driver's-side door holder.

    Source: 49 CFR 177.817(e)(2)(i). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  22. Before leaving the controls of a truck carrying a covered hazardous shipment, where may you leave its required shipping paper?

    Correct answer: On the driver's seat or in the driver's-side door holder.

    The rule specifies the driver's seat or the holder on the inside of the driver's door so authorities can find the paper.

    Source: 49 CFR 177.817(e)(2)(ii). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  23. Required hazardous-material papers are carried with other paperwork. How should the driver distinguish them?

    Correct answer: Use a distinctive tab or put them first.

    Readily recognizable shipping papers help authorities during accidents and inspections. This is distinct from marking hazardous entries within one mixed shipping paper.

    Source: 49 CFR 177.817(e)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  24. For a non-waste hazardous-material shipment, how long must a receiving motor carrier retain the required shipping-paper copy?

    Correct answer: One year after the carrier accepts the material.

    The receiving carrier's ordinary non-waste retention period is one year; hazardous waste has a three-year period. Providers of shipping papers have a different two-year non-waste requirement under 172.201(e).

    Source: 49 CFR 177.817(f); compare 172.201(e). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  25. A shipment's paperwork looks correct, but required hazard markings are missing from its packages. What should the driver do?

    Correct answer: Have the shipment brought into compliance before accepting it.

    The handbook assigns carriers responsibility to refuse improper shipments. Shipping papers, package markings and labels serve different purposes and must agree.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.2.1–9.2.3, physical PDF page 91. Reviewed September 14, 2026. ↗

  26. What does a material's hazard class communicate?

    Correct answer: The kind of transportation hazard assigned to the material.

    Hazard classes organize materials by their transportation hazards. They are not cargo-value or driver-experience ratings.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.3.1; Figure 9.1 class headings, physical PDF page 92. Reviewed September 14, 2026. ↗

  27. What is the purpose of the four-digit UN or NA identification number associated with a hazardous shipment?

    Correct answer: Identify the listed material or entry for reference and response.

    Identification numbers connect the shipment to regulatory and emergency references. One number can describe an entry covering more than one chemical; it is not necessarily unique to a single substance.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.3.3, identification numbers, physical PDF page 93. Reviewed September 14, 2026. ↗

  28. Which Hazardous Materials Table column gives the proper shipping name?

    Correct answer: Column 2.

    Column 2 provides the hazardous-material descriptions and proper shipping names. The proper shipping name is shown in ordinary Roman print, not the italic descriptive text.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.3.3, Column 2, physical PDF page 93. Reviewed September 14, 2026. ↗

  29. Where does the Hazardous Materials Table identify required hazard labels?

    Correct answer: Column 6.

    Column 6 indicates label requirements. This is separate from the identification number in Column 4 and packaging instructions in Column 8.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.3.3, Figure 9.4 label-code column (6), physical PDF page 93. Reviewed September 14, 2026. ↗

  30. Absent an applicable exception, where must required placards be displayed on a transport vehicle containing hazardous materials?

    Correct answer: On each side and each end.

    The general rule specifies each side and each end, with the placards appropriate to the material. Other provisions contain visibility, combination-vehicle and packaging exceptions.

    Source: 49 CFR 172.504(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  31. A highway shipment contains 200 pounds of Division 4.3 material with no applicable exception. Does being below 1,001 pounds remove its placarding requirement?

    Correct answer: No; Division 4.3 is in Table 1.

    Division 4.3 is a Table 1 hazard. The general less-than-1,001-pound exception for certain Table 2 non-bulk loads does not apply.

    Source: 49 CFR 172.504(a), (c), (e) Table 1. Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  32. A truck carries 900 pounds aggregate gross weight of ordinary Class 3 material in non-bulk packages. No subsidiary-hazard or other special requirement applies. What does 172.504(c) permit?

    Correct answer: Transport without a placard under the stated weight exception.

    The exception is for less than 1,001 pounds aggregate gross weight of Table 2 hazardous material in the stated circumstances. It does not erase other hazardous-material requirements.

    Source: 49 CFR 172.504(c). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  33. When applying the Table 2 aggregate gross-weight placarding threshold, does packaging weight count?

    Correct answer: Yes; gross weight includes packaging and contents.

    The threshold uses the gross weight of the hazardous packages, not merely net product weight or the vehicle's own weight.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.8, Gross weight or gross mass; 172.504(c), physical PDF page 106. Reviewed September 14, 2026. ↗

  34. Can a bulk package rely on the general less-than-1,001-pound Table 2 placarding exception merely because it contains little material?

    Correct answer: No; that exception expressly excludes bulk packagings.

    Bulk-packaging and special subsidiary-hazard rules must be checked separately. The non-bulk aggregate-weight exception is not a general small-residue exemption for tanks.

    Source: 49 CFR 172.504(c), (d). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  35. A vehicle carries qualifying non-bulk packages from two Table 2 categories requiring different placards. Neither category reaches 2,205 pounds loaded at one facility. Which option may be available?

    Correct answer: A DANGEROUS placard instead of their separate Table 2 placards.

    172.504(b) allows the DANGEROUS option for the stated mixed non-bulk Table 2 load. It does not replace Table 1 or other separate requirements.

    Source: 49 CFR 172.504(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  36. A qualifying mixed non-bulk load uses DANGEROUS placards. One facility loads 2,300 pounds aggregate gross weight of Class 8 material. What additional category display is required?

    Correct answer: The CORROSIVE placard for that category.

    When at least 2,205 pounds of one Table 2 category is loaded at one facility, its specified category placard must be applied.

    Source: 49 CFR 172.504(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  37. For a domestic Class 9 shipment in bulk packaging, what is true even though a CLASS 9 placard is not required?

    Correct answer: The bulk packaging still needs the appropriate identification-number marking.

    The domestic placard exception does not remove bulk identification marking. The number can appear on the authorized Class 9 placard, orange panel or white square-on-point display.

    Source: 49 CFR 172.504(f)(9). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  38. A required placard is partly hidden behind a ladder. What is the appropriate correction?

    Correct answer: Place or display it clear of the obstruction.

    Required placards must meet visibility requirements and be located clear of ladders, pipes, doors and other devices.

    Source: 49 CFR 172.516(a), (c)(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  39. How far must a placard be from advertising or other markings that could reduce its effectiveness?

    Correct answer: At least 3 inches.

    172.516(c)(4) requires separation from interfering markings and in any case at least three inches.

    Source: 49 CFR 172.516(c)(4). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  40. For a tractor and cargo body, may the required front placard be displayed on the front of the truck-tractor?

    Correct answer: Yes; it may be there instead of or in addition to the cargo-body front.

    The rule expressly allows the required front display on the tractor. Other applicable placarding and visibility requirements remain.

    Source: 49 CFR 172.516(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  41. Hazardous-material packages are not permanently attached to the vehicle. What must their securement prevent during normal transportation?

    Correct answer: Shifting, including movement relative to other packages.

    Packages must be secured against normal transit movement. Loading must also minimize the chance of damage to valves and fittings.

    Source: 49 CFR 177.834(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  42. A package bears required orientation arrows. How must it be carried?

    Correct answer: In the indicated orientation throughout transportation.

    Required orientation markings control both loading position and the package's position during transport.

    Source: 49 CFR 177.834(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  43. Before loading or unloading hazardous material, what must be done to prevent the vehicle from moving?

    Correct answer: Securely set the parking brake and take other reasonable precautions.

    The rule requires the handbrake to be securely set and other reasonable measures against movement. Hoses and people are not vehicle restraints.

    Source: 49 CFR 177.834(e). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  44. A tool could damage a hazardous package's closure during unloading. Should it be used?

    Correct answer: No; use handling equipment that will not damage containment.

    Tools likely to impair a package or its closure must not be used. The restriction concerns damaging tools, not a blanket ban on handling equipment.

    Source: 49 CFR 177.834(f). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  45. A cargo-tank unloading operation uses the ordinary in-person attendance method, with no special exception or alternative system. How close must the qualified person remain?

    Correct answer: Within 25 feet of the cargo tank.

    The ordinary method requires the qualified person within 25 feet, alert, and with the prescribed unobstructed view to the maximum extent practicable. Authorized alternative methods and product-specific exceptions have their own conditions.

    Source: 49 CFR 177.834(i)(3)(i). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  46. For ordinary in-person cargo-tank attendance, which person is qualified?

    Correct answer: One trained for the hazards and emergencies and able and authorized to move it.

    The attendant must know the material's hazards and emergency procedures and have authority and means to move the tank under this attendance method.

    Source: 49 CFR 177.834(i)(4). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  47. An approved remote cargo-tank monitoring system loses its monitoring capability during transfer. What must happen?

    Correct answer: Terminate transfer immediately and restore compliant attendance.

    The remote-system alternative requires immediate termination on loss of monitoring capability. A qualified person must immediately resume the required in-person attendance after remote-system failure.

    Source: 49 CFR 177.834(i)(3)(ii)(C), (E). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  48. An ordinary hazardous-liquid cargo tank still contains product. One manhole is unsecured. May it be driven a short distance to the exit?

    Correct answer: No; secure the manhole before moving the tank.

    The cargo-tank rule requires manhole closures closed and secured regardless of the quantity carried, subject to its stated empty-tank exception. A short distance is not itself an exception.

    Source: 49 CFR 177.834(j). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  49. Two hazardous products each have correct papers. What else must be checked before placing them together in the same cargo space?

    Correct answer: Whether the applicable segregation rules allow that combination.

    Properly documented products can still be incompatible. The handbook points to the federal segregation rules; documentation alone does not authorize mixed loading.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.4.2, Mixed loads, physical PDF page 100. Reviewed September 14, 2026. ↗

  50. A visitor wants to smoke next to a truck being unloaded with Class 3 flammable liquid. What should the driver do?

    Correct answer: Keep smoking and other ignition sources away from the operation.

    Smoking on or about the vehicle during the covered loading or unloading operation is forbidden. The rule also requires care to keep flames and lit smoking materials away.

    Source: 49 CFR 177.834(c)–(d). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  51. A placarded vehicle requires attendance. The attendant is outside, 80 feet away, but a building blocks the view. Does this meet the attendance definition?

    Correct answer: No; the vehicle must be in unobstructed view.

    An outside attendant must be within 100 feet and have an unobstructed view. On the vehicle, the attendant must be awake and not in a sleeper berth.

    Source: 49 CFR 397.5(d)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  52. A placarded vehicle needs an attendant. Does a driver asleep in the sleeper berth satisfy the rule?

    Correct answer: No; the on-vehicle attendant must be awake and outside the sleeper berth.

    The attendance definition specifically excludes sleeping and the sleeper berth. Its alternative outside position requires distance and unobstructed-view conditions.

    Source: 49 CFR 397.5(d)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  53. What makes a parking area a safe haven for unattended Division 1.1, 1.2 or 1.3 loads?

    Correct answer: Specific written approval by a local, state or federal authority.

    Safe haven is a defined approval status, not a driver's description of a convenient place. The other applicable attendance conditions still matter.

    Source: 49 CFR 397.5(b), (d)(3). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  54. A truck containing Division 1.2 material is parked four feet from the traveled part of a public highway. Is this allowed under the parking rule?

    Correct answer: No; it cannot be parked on or within five feet.

    172.504 identifies this hazard for placarding, and 397.7(a)(1) forbids parking on or within five feet of the traveled portion of a public street or highway.

    Source: 49 CFR 397.7(a)(1). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  55. A driver of a placarded Class 3 vehicle wants to park within five feet of the traveled roadway for personal shopping. Does the brief operational-necessity exception cover that stop?

    Correct answer: No; personal shopping is not the stated operational necessity.

    The exception requires a brief operational necessity and impracticability of parking elsewhere. It does not provide a general convenience-parking exemption.

    Source: 49 CFR 397.7(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  56. A Division 1.1 vehicle is to be parked 200 feet from a dwelling, with no qualifying operational necessity. Is that within the prohibited zone?

    Correct answer: Yes; the rule uses 300 feet in these circumstances.

    The rule restricts parking within 300 feet of bridges, tunnels, dwellings and places where people work or assemble, with a narrowly stated brief operational exception.

    Source: 49 CFR 397.7(a)(3). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  57. Before parking a Division 1.3 vehicle on private property, what must the person in charge of that property know and provide?

    Correct answer: Awareness of the hazardous contents and consent to park.

    Knowledge and consent must come from the person in charge of the property, who must be aware of the nature of the hazardous materials.

    Source: 49 CFR 397.7(a)(2). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  58. How close may a vehicle carrying covered hazardous materials be parked to an open fire under 397.11?

    Correct answer: It must not be parked within 300 feet.

    The parking restriction is 300 feet. Passing an open fire is a separate issue requiring precautions to establish that the vehicle can safely pass without stopping.

    Source: 49 CFR 397.11(a)–(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  59. A placarded truck contains Class 3 flammable liquid. Someone stands 15 feet away with a lit cigarette. Is that far enough under the smoking rule?

    Correct answer: No; the prohibited area extends to 25 feet.

    397.13 prohibits smoking or carrying lit cigarettes, cigars or pipes on or within 25 feet of the listed hazardous-material vehicles.

    Source: 49 CFR 397.13(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  60. An empty tank vehicle previously carried placard-required Class 3 flammable liquid. Does emptying the liquid by itself remove the 25-foot smoking restriction?

    Correct answer: No; the rule also covers this empty tank vehicle.

    The rule expressly covers an empty tank motor vehicle used for the specified flammable liquid or gas service when marking or placarding was required.

    Source: 49 CFR 397.13(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  61. A truck containing covered hazardous materials stops to refuel its own fuel tank. What does the hazmat fueling rule require?

    Correct answer: Engine off, with a person controlling the fueling at the fill point.

    397.15 concerns fueling the motor vehicle itself. It requires the engine not to operate and a person to control the fueling process where the fuel tank is filled.

    Source: 49 CFR 397.15(a)–(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  62. A normal truck power unit carries hazardous materials in a quantity requiring placards. What is its minimum required extinguisher rating?

    Correct answer: One extinguisher rated at least 10 B:C.

    The placard-required power-unit minimum is 10 B:C. The extinguisher must also be accessible, charged and securely mounted; a rating does not authorize untrained cargo-fire response.

    Source: 49 CFR 393.95(a)(1)(i), (a)(2)–(4). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  63. An empty cargo tank used for Class 3 flammable-liquid transportation breaks down. Which warning equipment is appropriate to carry?

    Correct answer: Required reflective triangles, without flame-producing signals.

    Flame-producing signals must not be carried on the specified cargo tank whether loaded or empty. The required reflective triangles provide a non-flame warning option.

    Source: 49 CFR 393.95(f)(1), (g). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  64. When does the tire rule for covered hazardous-material vehicles require examination of each tire?

    Correct answer: At the start of each trip and each time the vehicle is parked.

    397.17(a) specifies trip-start and each-parking examinations. It does not replace the driver's other inspection duties.

    Source: 49 CFR 397.17(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  65. A covered hazmat truck has a flat tire. Where may it be driven under the repair-location exception?

    Correct answer: To the nearest safe place for the necessary repair.

    The tire must be repaired, replaced or properly inflated before driving, except travel to the nearest safe place to perform that work. Other safe-operation requirements still apply.

    Source: 49 CFR 397.17(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  66. A tire on a covered hazmat vehicle is found overheated. What must be resolved before further operation?

    Correct answer: The cause of the overheating must be corrected.

    The driver must cause the overheated tire to be removed to a safe distance and correct the cause before operating again. Arrange qualified help and maintain applicable parking and attendance precautions.

    Source: 49 CFR 397.17(c)–(d). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  67. A Class 3 placard-required truck approaches an ordinary railroad grade crossing with no applicable exception. Where must it stop?

    Correct answer: Between 15 and 50 feet from the tracks.

    For a covered vehicle, stop within 50 feet but not closer than 15, then look and listen. Use a gear that allows crossing without shifting.

    Source: 49 CFR 392.10(a), (a)(3)(vi). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  68. A cargo tank formerly used to transport hazardous material is empty. At an ordinary grade crossing with no applicable exception, does empty status alone remove the federal stop requirement?

    Correct answer: No; the rule includes loaded and empty hazardous-material cargo tanks.

    392.10(a)(4) expressly covers such cargo tanks whether loaded or empty. The specific crossing exceptions in paragraph (b) must be considered separately.

    Source: 49 CFR 392.10(a)(4), (b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  69. After making a required railroad stop, how should the driver choose a gear for crossing?

    Correct answer: Choose one that allows the whole crossing without shifting.

    The rule requires a gear that permits completing the crossing without a gear change and prohibits shifting while crossing.

    Source: 49 CFR 392.10(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  70. Which shipping information helps responders locate the appropriate entry in the Emergency Response Guidebook?

    Correct answer: The proper shipping name and material identification number.

    The handbook explains that ERG information is indexed by proper shipping name and identification number. Accurate hazard communication helps responders find the applicable guidance.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.1, physical PDF page 103. Reviewed September 14, 2026. ↗

  71. You notice an unfamiliar leak from hazardous cargo. How should you identify the material without deliberately exposing yourself?

    Correct answer: Use available shipping information from a safe position.

    Do not identify a hazardous leak by touching, tasting or deliberately smelling it. Use papers and safe observations, keep away and seek qualified emergency assistance.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.2–9.7.3, physical PDF page 103. Reviewed September 14, 2026. ↗

  72. Hazardous cargo is leaking and the driver wants to continue to a truck stop to find help. What is the appropriate response?

    Correct answer: Stop safely and call or send for help instead of spreading the leak.

    The handbook warns against continuing a leaking shipment to find a phone or truck stop. Movement is limited to what safety requires and what can be done without endangering people or spreading contamination.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.3, physical PDF page 103. Reviewed September 14, 2026. ↗

  73. Hazardous cargo is burning and the driver lacks specialized firefighting training and equipment. What should the driver do?

    Correct answer: Withdraw, warn others and summon emergency responders.

    A hazardous cargo fire calls for trained, equipped responders. Keep shipping information available when safely possible and do not put yourself into the hazard.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.3, physical PDF page 103. Reviewed September 14, 2026. ↗

  74. While waiting for responders at a hazardous-material release, which location does the handbook recommend for people kept away from the scene?

    Correct answer: Far away and upwind of the release.

    Keep people far away and upwind and warn them about the danger. Actual isolation distances and protective actions depend on the material and responders' guidance.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.2, physical PDF page 103. Reviewed September 14, 2026. ↗

  75. What information is especially useful when someone contacts responders about your hazardous-cargo incident?

    Correct answer: Exact location, incident details and known shipment identification.

    Give the exact location and direction of travel, what happened, carrier details and known proper shipping name, class and identification number. Do not approach the hazard merely to gather missing information.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.3, physical PDF page 103. Reviewed September 14, 2026. ↗

  76. A transportation incident meets 171.15's NRC telephone-report criteria. When must the person in physical possession notify the NRC?

    Correct answer: As soon as practical, no later than 12 hours after occurrence.

    The telephone deadline is as soon as practical and within 12 hours. This is not permission to delay emergency assistance; the detailed written report has a separate deadline.

    Source: 49 CFR 171.15(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  77. A hazardous material directly causes the public to be evacuated for exactly one hour. Does this meet the evacuation trigger for NRC telephone reporting?

    Correct answer: Yes; the trigger is one hour or more.

    The current rule includes an evacuation lasting exactly one hour. The older handbook's more-than-one-hour wording should not be used to exclude this incident.

    Source: 49 CFR 171.15(b)(1)(iii). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  78. A hazardous material directly causes an injury requiring admission to a hospital during transportation. Does that meet an NRC telephone-report trigger?

    Correct answer: Yes; hospital admission is one of the listed triggers.

    An injury requiring admittance to a hospital as a direct result of the hazardous material is a listed trigger. Mere cost estimates are not a substitute for checking the actual criteria.

    Source: 49 CFR 171.15(b)(1)(ii). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  79. After an incident covered by 171.16, what is the ordinary deadline for the detailed hazardous-material incident report?

    Correct answer: Within 30 days of discovering the incident.

    The person in physical possession at the incident must submit the required DOT Form F 5800.1 within 30 days of discovery. This is separate from any prompt emergency call and NRC telephone notice.

    Source: 49 CFR 171.16(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗

  80. At pickup, a Division 6.2 package is damaged and appears to be leaking. What should the driver do?

    Correct answer: Do not accept it; contact the supervisor about the damage.

    The handbook says damaged or leaking infectious-substance packages should not be accepted and the supervisor should be contacted. Avoid contact and leave specialist handling to trained personnel.

    Source: Colorado Commercial Driver License Manual (06/15/23), Section 9.7.4, Class 6, physical PDF page 104. Reviewed September 14, 2026. ↗

Report a problem with this question

Question reference: co-cdl-hazmat-001

Opens a draft in your email app. Review and send it there; nothing is sent automatically.

Draft a correction email

Contact details & help

Study tools & test information

Home / Colorado / CDL

Colorado hazardous materials practice

80 explained questions. Choose a 16-question test or study the full topic question set below.

All topics and study tools

What to study

Training responsibilities, shipping descriptions, emergency information, placarding thresholds and exceptions, package handling, cargo-tank attendance, parking, tires, rail crossings and incident reporting. Every answer has an explanation.

The five short tests divide these 80 questions without overlap. Random practice tests reuse the same questions. This is not an official exam or complete CDL preparation; practice lengths and score targets are learning aids.

Practice does not provide an H endorsement, TSA clearance, registered entry-level driver training or employer hazmat training. Follow the requirements for your cargo and operation. Product-specific compatibility, handling, security and emergency procedures require appropriate training; do not attempt to handle a leak or cargo fire without it.

Sources reviewed September 14, 2026: the Colorado DMV-linked Commercial Driver License Manual (06/15/23), Section 9, and the individual federal references. Rule questions use the official eCFR snapshot dated September 10, 2026. Where the older handbook differs, these questions follow the cited current rule, including shipping-paper accessibility and the one-hour evacuation reporting threshold.

Official handbook sectionOfficial ELDT requirementsReview CDL mistakesTank vehiclesGeneral knowledge