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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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: Maryland Commercial Driver’s License Manual, DL-151 (02/26), February 2026; Section 9.2.1–9.2.3, package identification and acceptance; physical PDF page 217 (printed 217); public mirror of the Maryland manual; reviewed September 15, 2026. ↗
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: Maryland Commercial Driver’s License Manual, DL-151 (02/26), February 2026; Section 9.3.1, the meaning of hazard class; physical PDF page 218 (printed 218); public mirror of the Maryland manual; reviewed September 15, 2026. ↗
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: Maryland Commercial Driver’s License Manual, DL-151 (02/26), February 2026; Section 9.3.3, identification numbers; physical PDF page 221 (printed 221); public mirror of the Maryland manual; reviewed September 15, 2026. ↗
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: Maryland Commercial Driver’s License Manual, DL-151 (02/26), February 2026; Section 9.3.3, Column 2 proper shipping names; physical PDF page 222 (printed 222); public mirror of the Maryland manual; reviewed September 15, 2026. ↗
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: Maryland Commercial Driver’s License Manual, DL-151 (02/26), February 2026; Section 9.3.3, Column 6 label codes; Figure 9.4 on page 222; physical PDF page 223 (printed 223); public mirror of the Maryland manual; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
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 11, 2026; reviewed September 15, 2026. ↗
