[Header] PHMSA - U.S. Department of Transportation - Pipeline and Hazardous materials Safety Adminis
spacer
For the Public
 
Hazmat Safety Community Pipeline Safety Community Media | Congress
 
Doing Business with PHMSA
 
PHMSA Home
binders
Hazmat Interpretations

The Pipeline and Hazardous Materials Safety Administration, Office of Hazardous Materials Safety (OHMS) provides written clarifications of the Hazardous Materials Regulations (HMR; 49 CFR Parts 100-185) in the form of interpretation letters.  These letters reflect the agency's current application of the HMR to the specific facts presented by the person requesting the clarification.  Interpretations are one form of Guidance provided by OHMS.

Interpretations do not create legally-enforceable rights or obligations and are provided to help the public understand how to comply with the HMR. 

OHMS regularly reviews interpretations on this site for accuracy and applicability.  Interpretation letters from the last ten years are published here to provide the public with a greater awareness and understanding of the HMR.  Letters of interpretation which are found to be inaccurate or no longer applicable are removed and may be revised and reissued if warranted.  Letters which do not appear on this website may no longer be valid.

We welcome feedback from the hazmat safety community to ensure the most recent and accurate letters of interpretation are provided here.  Questions or concerns about a specific letter or topic should be directed to the Hazardous Materials Information Center.

Search Interpretations

Search Tips
An unsigned text version with a signed Portable Document Format (PDF) version (a file that allows you to view and print the document in its original format) of each letter is provided. Click the links above to view interpretation letters. You can also enter a word or words in the search field and click Search to locate that term within the letters. Additionally, all letters of interpretation posted to the website are fully searchable. This means you can enter a word or words in the search field and click "Search" to locate that term within a letter.
Questions?

You can obtain information and answers to your questions on compliance with the hazardous materials regulations (49 CFR parts 171 through 180) and interpretations of those regulations by contacting PHMSA's Office of Hazardous Materials Safety as follows:

Hazardous Materials Information Center at 1-800-HMR-4922 (1-800-467-4922; or 202-366-4488 for Washington DC residents) Monday through Friday from 9:00 am to 5:00 pm (EST) except Federal holidays. After hours, you can leave a recorded message and your call will be returned by the next business day.

Send a letter, with your return address and a daytime telephone number, to:

U.S. DOT
PHMSA Office of Hazardous Materials Standards
Attn: PHH–10
East Building
1200 New Jersey Avenue, SE.
Washington, DC 20590–0001

Sign Up for Updates
envelope
Click below to sign up to receive email notification of changes to specific areas of this site.
Look Up
Locate official documents and records
 
Regulations.gov
One-stop site to find, view, and comment on Federal regulations and other Federal actions.
 
eCFR - Code of Federal Regulations
Electronic records updated daily.
 
CFR Retrieve by Citation
Title, Part, and either a Section Number or a Subpart letter are required.
 
Federal Register
The official daily publication for rules, proposed rules, and notices of Federal agencies and organizations, as well as Executive Orders and other presidential documents.
 
Grants.gov
Grant programs offered by all Federal grant making agencies.
 
FedStar
integrates information necessary to support State Pipeline Safety offices as well as PHMSA in its management of those interfaces with state organizations.
 
Forms.gov
Provides citizens access to federal agency forms.
 
USA.gov
Government information by topic.
 
The United States Code
Provides codification by subject matter of the general and permanent laws of the United States.
Careers  |  Contact Us  |  No Fear  |  Privacy Policy  |  FOIA  |  Accessibility  |  FAQs  |  Web Policies  |  Site Map  |  Download Acrobat