DOT Hazardous Materials Transportation 3 — Questions and Answers
Question 1: Under 49 CFR 173, what packing group designation indicates the GREATEST danger for a hazardous material?
- Packing Group I (Correct answer)
- Packing Group II
- Packing Group III
- Packing Group IV
Correct answer: Packing Group I
Packing Group I (PG I) designates materials presenting the greatest danger and requires the most stringent packaging standards.
Question 2: A vehicle transporting Division 1.3 explosives must keep what minimum distance from other vehicles while stopped for refueling?
- 25 feet
- 50 feet (Correct answer)
- 100 feet
- 300 feet
Correct answer: 50 feet
Vehicles carrying Division 1.3 explosives must maintain at least 50 feet of separation from other vehicles at rest, per 49 CFR 397.7.
Question 3: Which of the following describes an 'overpack' in hazardous materials transportation?
- A package that exceeds the maximum weight limit
- An enclosure used to consolidate one or more packages for handling (Correct answer)
- A replacement outer container used when the original is damaged
- A UN-certified container used for bulk liquids
Correct answer: An enclosure used to consolidate one or more packages for handling
An overpack is an enclosure used to consolidate two or more packages into a single unit for ease of handling per 49 CFR 171.8.
Question 4: When transporting poison inhalation hazard (PIH) materials, which placard takes precedence over all others?
- FLAMMABLE GAS
- POISON GAS or POISON INHALATION HAZARD (Correct answer)
- CORROSIVE
- DANGEROUS
Correct answer: POISON GAS or POISON INHALATION HAZARD
PIH placards (POISON GAS or POISON INHALATION HAZARD) always take precedence and must be displayed regardless of other hazard classes present.
Question 5: A DOT inspector finds that a hazmat package's label is obscured by a shipping sticker. What regulation does this violate?
- 49 CFR 172.406 — labels must remain visible and legible (Correct answer)
- 49 CFR 173.24 — general packaging requirements
- 49 CFR 177.817 — driver inspection requirements
- 49 CFR 172.300 — marking requirements
Correct answer: 49 CFR 172.406 — labels must remain visible and legible
49 CFR 172.406 requires that hazmat labels remain clearly visible and not be obscured by other markings or attachments during transport.
Question 6: Which class of hazardous material is assigned to flammable liquids with a flash point below 60°C (140°F)?
- Class 2
- Class 3 (Correct answer)
- Class 4
- Class 8
Correct answer: Class 3
Class 3 covers flammable liquids, defined as liquids with a flash point below 60°C (140°F) under 49 CFR 173.120.
Question 7: What does the Emergency Response Guidebook (ERG) number on a shipping paper help emergency responders determine?
- The carrier's insurance policy number
- The appropriate emergency response actions for the material (Correct answer)
- The driver's training certification level
- The vehicle's gross weight rating
Correct answer: The appropriate emergency response actions for the material
The ERG guide number directs emergency responders to the correct guidebook page detailing safe distances, fire suppression, and first aid for that specific hazardous material.
DOT Hazardous Materials Transportation 3
Under 49 CFR 173, what packing group designation indicates the GREATEST danger for a hazardous material?