A truck carries enough hazardous material to require placards. What minimum extinguisher rating must its power unit carry under 393.95(a)?
Correct answer: 10 B:C.
The placarded-hazmat power unit needs an extinguisher rated at least 10 B:C. The lower non-placarded alternatives do not satisfy this requirement.
Source: 49 CFR 393.95(a), October 1, 2025 edition, printed page 613; unaffected by the cited 2026 flare/fuse amendments; reviewed September 21, 2026. ↗
A fully charged extinguisher is secured behind cargo that must first be unloaded. Does this meet the required installation standard?
Correct answer: No; it must also be readily accessible.
Required equipment must be accessible as well as filled and secured. Preventing movement does not excuse burying the extinguisher behind freight.
Source: 49 CFR 393.95(a), October 1, 2025 edition, printed page 613; unaffected by the cited 2026 flare/fuse amendments; reviewed September 21, 2026. ↗
For winter operation, which extinguisher-agent condition is required by 393.95(a)?
Correct answer: It must not need protection from freezing.
The required extinguishing agent must not need freezing protection. A correct capacity rating alone does not settle the cold-weather requirement.
Source: 49 CFR 393.95(a), October 1, 2025 edition, printed page 613; unaffected by the cited 2026 flare/fuse amendments; reviewed September 21, 2026. ↗
An extinguisher has no pressure gauge but provides another way to visually determine whether it is fully charged. Is the missing gauge alone disqualifying?
Correct answer: No; an acceptable alternative visual indication can qualify.
FMCSA's guidance does not require a pressure gauge as the only visual charge indicator. This does not waive the other extinguisher requirements.
Source: FMCSA 393.95 guidance question 1, effective May 4, 1997; visual indication of charge, not current rule text; reviewed September 21, 2026. ↗
A cargo tank used for Class 3 flammable liquids is empty. May the truck carry unlit fusees (flame-producing road flares)?
Correct answer: No; the flame-device carriage ban also covers empty tanks.
Under the amended rule, loaded and empty tanks used for Class 3 cargo are covered. The restriction concerns carrying flame devices, not just lighting them.
Source: FMCSA final rule 2026-03261, 91 FR 7867, effective March 23, 2026; amended 393.95(f)–(g), printed page 7870, physical PDF page 4; reviewed September 21, 2026. ↗
A commercial vehicle uses compressed gas as motor fuel but carries ordinary freight. May it carry fusees under 393.95(g)?
Correct answer: No; compressed-gas motor fuel also triggers the ban.
The flame-device restriction includes compressed-gas-powered commercial vehicles. Ordinary freight does not remove that motor-fuel condition.
Source: FMCSA final rule 2026-03261, 91 FR 7867, effective March 23, 2026; amended 393.95(f)–(g), printed page 7870, physical PDF page 4; reviewed September 21, 2026. ↗
An old equipment checklist lists three liquid-burning emergency flares as an alternative to triangles. What changed in March 2026?
Correct answer: The liquid-burning-flare option was removed.
Effective March 23, 2026, FMCSA removed that obsolete option. Follow the current warning-device requirements, including applicable flame-device restrictions.
Source: FMCSA final rule 2026-03261, 91 FR 7867, effective March 23, 2026; amended 393.95(f)–(g), printed page 7870, physical PDF page 4; reviewed September 21, 2026. ↗
A checklist says federal 393.95(b) always requires spare electrical fuses unless circuit breakers are fitted. What changed in April 2026?
Correct answer: The federal spare-fuse carriage requirement was removed.
FMCSA removed paragraph (b) effective April 20, 2026. Carrying spare electrical fuses voluntarily is not prohibited; fusees are a different item.
Source: FMCSA final rule 2026-03262, 91 FR 7877, effective April 20, 2026; removes and reserves 393.95(b), printed page 7880, physical PDF page 4; reviewed September 21, 2026. ↗
Hazardous cargo causes nearby residents to be evacuated for exactly one hour during transportation. Does this reach the public-evacuation NRC-notice threshold?
Correct answer: Yes; one hour or more qualifies.
The cited reporting guidance includes a public evacuation lasting one hour or more when directly caused by hazardous material. Exactly one hour meets that threshold.
Source: PHMSA Guide for Preparing Hazardous Materials Incidents Reports, revised January 2004, still linked from PHMSA's September 7, 2023 FAQ; printed page 11, physical PDF page 13, 171.15(a)–(b). Dated guidance, not a verified 2026 rule edition; reviewed September 21, 2026. ↗
You must make an initial NRC report, but some cargo details are not yet known. What information belongs in the notice?
Correct answer: Reporter/contact details, location, injuries and available material/hazard information.
Provide the required incident and contact information, including available material details and continuing danger. Missing final findings do not justify delaying required notice.
Source: PHMSA Guide for Preparing Hazardous Materials Incidents Reports, revised January 2004, still linked from PHMSA's September 7, 2023 FAQ; printed page 11, physical PDF page 13, 171.15(a)–(b). Dated guidance, not a verified 2026 rule edition; reviewed September 21, 2026. ↗
After exposure to hazardous cargo, a person is examined in an emergency room and released without admission. Does that alone meet the hospital-admission reporting criterion?
Correct answer: No; treatment and release is not hospital admission.
PHMSA distinguishes admission as a patient from treatment followed by release. Other reporting criteria may still apply; this is not a blanket exemption.
Source: PHMSA interpretation 03-0028, May 21, 2003, questions 3–4; dated interpretation of fatality and hospital-admission criteria, not current regulation text; reviewed September 21, 2026. ↗
A collision kills someone, but the hazardous cargo remains intact and did not cause the death. Does the cargo's presence alone satisfy the hazmat-fatality NRC criterion?
Correct answer: No; that criterion requires a death directly resulting from the hazardous material.
PHMSA's interpretation requires the stated causal connection. Other accident-reporting duties or other hazardous-material triggers can still apply.
Source: PHMSA interpretation 03-0028, May 21, 2003, questions 3–4; dated interpretation of fatality and hospital-admission criteria, not current regulation text; reviewed September 21, 2026. ↗
Undeclared hazardous material is discovered during transportation, without leakage. Is a detailed incident report required?
Correct answer: Yes, discovery itself is reportable.
PHMSA says discovery of undeclared hazardous material requires a detailed report even without discharge.
Source: PHMSA Hazardous Materials Incident Reporting FAQ, updated September 7, 2023; questions 6–9 and 15, dated agency guidance; reviewed September 21, 2026. ↗
A radioactive shipment's outer package breaks, but the inner receptacle remains intact. Does PHMSA require NRC notification?
Correct answer: Yes, despite the intact inner receptacle.
PHMSA's FAQ treats this outer-package breakage as reportable without requiring a release or overexposure.
Source: PHMSA Hazardous Materials Incident Reporting FAQ, updated September 7, 2023; questions 6–9 and 15, dated agency guidance; reviewed September 21, 2026. ↗
At delivery, the driver stays and observes unloading when a reportable hazmat incident occurs. Who must file?
Correct answer: The carrier remains responsible.
PHMSA includes unloading while the carrier participates or observes within transportation for this reporting duty.
Source: PHMSA Hazardous Materials Incident Reporting FAQ, updated September 7, 2023; questions 6–9 and 15, dated agency guidance; reviewed September 21, 2026. ↗
After delivery is complete and the carrier has left, the consignee unloads and spills material. Which reporting statement is correct?
Correct answer: HMR transportation reporting need not apply; other laws may.
PHMSA distinguishes unloading after transportation ends. Environmental and other reporting obligations can still apply.
Source: PHMSA Hazardous Materials Incident Reporting FAQ, updated September 7, 2023; questions 6–9 and 15, dated agency guidance; reviewed September 21, 2026. ↗
