Getting your Trinity Audio player ready...

Author: Stephen Glazier

null

Knowing whether your fleet is subject to Department of Transportation (DOT) regulations is critical. We outlined vehicle-weight regulations in Are You Subject to DOT Regulations (Part 1): Capacity Weight and Threshold and passenger count in Are You Subject to DOT Regulations (Part 2): Passengers and Payment Type. This article addresses what makes vehicles subject to regulations governing transportation of hazardous substances and select agents and toxins.

Several agencies have regulations related to these materials, including the DOT, the Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Health and Human Services (HHS), the Department of Homeland Security (DHS), the Centers for Disease Control (CDC) and others. In some cases, regulations overlap.

As it relates to these regulations, you should be aware of the following two groupings of substances.

Regulations related to transporting hazardous substances

The DOT determines the list of hazardous substances in 49 C.F.R. 172.101 in the hazardous materials table.1

Most of the substances listed don't require a vehicle to be placarded until the total weight of the substance reaches 1,100 lbs.; however, some substances listed require a placard regardless of the amount or type of vehicle used to transport them. They include:

  • Explosives in division 1.1, 1.2, or 1.3
  • Inhalation hazards in division 2.3 or 6.1
  • Radioactive materials, division 7
  • Organic peroxide division 5.2, Type B, temperature-controlled

The DOT's Hazardous Materials Markings, Labeling and Placarding Guide may be helpful when sorting through weights and placarding requirements.2 If a placard is required, the vehicle is considered a commercial motor vehicle (CMV), and the driver must have a Class C commercial driver's license (CDL) to transport these substances in a light-duty vehicle.3

Regulations related to transporting select agents and toxins

HHS determines the list of select agents and toxins.4 Transporting any amount of these select agents or toxins requires your driver to have a Class C CDL. The DOT doesn't mandate placarding for these select agents or based on the hazardous materials table mentioned above,1 but the driver will still need a CDL Class C to transport in a light-duty vehicle.

This article doesn't address several regulatory considerations for hauling hazardous substances and/or select agents and toxins, such as labeling, prohibited transportation methods, reporting and declaration, and manifests

We recommend reviewing your pollution and commercial auto policies to ensure that your policies will protect your organization if you have an incident when transporting one of these substances. Many policies have exclusions that could affect the policy's response, and endorsements are available to help ensure that doesn't occur. Contact your Gallagher account executive to review your coverage.

Author Information


Sources

1"Part 172 — Hazardous Materials Table, Special Provisions, Hazardous Materials Communications, Emergency Response Information, Training Requirements, and Security Plans," Electronic Code of Federal Regulations, 16 Apr 2008.

2"DOT Chart 16: Hazardous Materials Markings, Labeling and Placarding Guide," US Department of Transportation, accessed 23 Apr 1016. PDF file.

3"Commercial Driver's License Program," Federal Motor Carrier Safety Administration, updated 4 Feb 2026.

4"73.3 HHS Select Agents and Toxins," Electronic Code of Federal Regulations, accessed 23 Apr 2026.