49 CFR Hazardous Materials Regulations
Current electronic text of the federal Hazardous Materials Regulations, including Parts 171 through 180.
Direct access to the primary sources used to research hazardous materials transportation, rail, highway, air, vessel, workplace, environmental and international dangerous goods requirements.
Use these links to confirm current regulatory language, locate agency interpretations, research permits and incidents, and verify the standards that apply to a specific material, package, mode or operation.
Last reviewed and updated: July 2026
Start with the current regulatory text, then review applicable interpretations, incorporated standards, permits and rulemaking history.
Current electronic text of the federal Hazardous Materials Regulations, including Parts 171 through 180.
Search PHMSA interpretations and broadly applicable FAQs addressing the HMR. Always check the date, cited section and whether later rulemaking has affected the answer.
Review final rules, proposed rules, notices, effective dates, compliance dates and the underlying regulatory history.
Research alternative requirements, party status, approval documents, competent-authority approvals and authorization status.
Use 49 CFR § 171.7 to determine the precise edition of an AAR, ASTM, ASME, ISO or other external standard incorporated into the HMR. The applicable edition may not be the newest commercial edition.
Access PHMSA guides covering shipping papers, packaging, training, security, lithium batteries, reverse logistics, registration and other common compliance subjects.
PHMSA provides assistance with the HMR, rulemakings, special permits, training materials and requests for formal interpretation.
A useful regulatory answer often requires more than locating a single paragraph. The applicable rule, definitions, special provisions, incorporated standards, modal requirements and later amendments may all affect the result.
Begin with the current regulatory text and verify its effective date.
Confirm how the regulation defines the material, person, package, activity and mode involved.
Review special provisions, modal rules, exceptions, approvals and incorporated standards.
Determine how the rule affects actual people, materials, equipment, procedures and field practices.
Tools for initial emergency response, required incident reporting, incident research and federal hazmat registration.
Initial-response guidance for transportation incidents involving hazardous materials and dangerous goods.
Review immediate telephonic reporting under § 171.15, written reporting under § 171.16 and Form DOT F 5800.1 requirements.
Search reported transportation incidents and review statistics by year, mode, location, material and consequence.
Determine who must register, review current registration instructions and access the electronic registration system.
Current FRA compliance guidance, one-time movement approval procedures and the principal rail and tank-car regulations.
FRA’s current hazardous materials compliance and inspection manual, issued January 15, 2025 and effective August 20, 2025.
Current FRA procedures for requesting a one-time movement approval for a nonconforming bulk package or tank car under 49 CFR § 174.50.
Direct links to carriage-by-rail, tank-car specification and continuing-qualification requirements.
Search current FRA compliance manuals, technical bulletins, safety advisories and other agency guidance by discipline.
Review the hazardous materials requirements that apply to transportation by public highway, together with separate FMCSA motor carrier safety, registration, driver, vehicle, inspection, and operating requirements.
Part 177 is the highway-mode portion of the Hazardous Materials Regulations. It addresses the acceptance, loading, unloading, handling, attendance, parking, routing, and transportation of hazardous materials by motor vehicle.
It is not the complete body of FMCSA motor carrier regulations. Broader carrier, driver, vehicle, hours-of-service, inspection, and operating requirements are primarily found elsewhere in 49 CFR.
FMCSA regulations address broader motor carrier safety and operating requirements, including driver qualifications, commercial driver licensing, hours of service, vehicle inspection and maintenance, operating rules, and safety management.
Research a motor carrier’s USDOT record, operating status, safety rating, inspection information and other public company data.
Review public inspection, crash and investigation information. SMS data should be interpreted in context and is not itself a federal safety rating.
Information about the security threat assessment required for drivers seeking or renewing a hazardous materials endorsement.
Domestic modal regulations must be evaluated together with the applicable international code, operator requirements, state variations and current addenda.
US air-transport regulations and passenger guidance for common hazardous materials and battery-powered devices.
Official international dangerous-goods requirements for air transport. Review the current edition together with all applicable addenda, corrigenda and state variations.
Current IMO information for the IMDG Code, including the 2024 Edition incorporating Amendment 42-24.
Current Postal Service requirements for hazardous, restricted and perishable mail, including material-specific mailability, packaging, marking and documentation provisions.
Canadian transportation requirements covering classification, documentation, safety marks, means of containment, training, emergency response, reporting and modal transportation.
Nuclear Regulatory Commission requirements and guidance affecting the design, certification and transportation of radioactive-material packages.
DOT classification and transportation requirements do not replace separate OSHA, EPA, state or local obligations that may apply to the same material or operation.
Resources covering workplace chemical classification, labels, safety data sheets, written programs and employee information and training.
Federal hazardous-waste identification, generator, transporter, treatment, storage, disposal and universal-waste requirements. State requirements may be more stringent.
Search environmental permits, inspections, violations, enforcement cases and compliance history by facility, location or regulatory program.
Research transportation accidents and major chemical incidents to understand recurring causes, failed controls and recommended preventive measures.
Search National Transportation Safety Board investigations, reports, dockets and safety recommendations across rail, highway, aviation, marine and pipeline modes.
Review independent investigations, root-cause findings, safety videos and recommendations arising from major chemical incidents.
Continue researching independently, obtain focused advice on a specific question, or establish ongoing access to experienced hazmat support.
Watch practical discussions of common hazmat requirements, risks, mistakes, and operational controls.
Visit the video library →Have a specific compliance, classification, packaging, transportation, storage, or operational question? Book a paid consultation for focused guidance on the issue or decision in front of you.
Book a Paid Expert Consultation →Establish ongoing access to experienced assistance applying hazardous materials requirements to real materials, packages, shipments, facilities, and operations.
Explore Helpdesk support →These links are provided for general research and convenience. Regulations, agency guidance, incorporated standards, international codes and website locations change. Confirm the current effective requirements, applicable jurisdiction, modal provisions, addenda, variations and official source documents before making a compliance decision.
The rule is only the beginning. STARS helps organizations determine what applies, how the requirements interact, where operational risk exists, and what practical steps are needed to move forward.