---
kind: "section"
citation: "49 C.F.R. § 105.20"
title: "49"
number: "105.20"
heading: "Guidance and interpretations."
url: "https://uscodex.org/cfr/49/105.20"
---

# §105.20. Guidance and interpretations.

- (a) **Hazardous materials regulations.** You can obtain information and answers to your questions on compliance with the hazardous materials regulations (49 CFR parts [171](/cfr/49/part171.md) through [180](/cfr/49/part180.md)) and interpretations of those regulations by contacting PHMSA's Office of Hazardous Materials Safety as follows:
  - (1) Call the Hazardous Materials Information Center at 1-800-467-4922 (in Washington, DC, call (202) 366-4488). The Center is staffed from 9 a.m. through 5 p.m. Eastern time, Monday through Friday except Federal holidays. After hours, you can leave a recorded message and your call will be returned by the next business day.
  - (2) E-mail the Hazardous Materials Information Center at infocntr@dot.gov.
  - (3) **Obtain hazardous materials safety information via the Internet at <I>http—** //www.phmsa.dot.gov.
  - (4) **Send a letter, with your return address and a daytime telephone number, to—** Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration, Attn: PHH-10, U.S. Department of Transportation, East Building, 1200 New Jersey Avenue, SE., Washington, DC 20590-0001.
- (b) **Federal hazardous materials transportation law and preemption.** You can obtain information and answers to your questions on Federal hazardous materials transportation law, [49 U.S.C. 5101](/usc/49/5101.md) et seq., and Federal preemption of State, local, and Indian tribe hazardous material transportation requirements, by contacting PHMSA's Office of the Chief Counsel as follows:
  - (1) Call the office of the Chief Counsel at (202) 366-4400 from 9 a.m. to 5 p.m. Eastern time, Monday through Friday except Federal holidays.
  - (2) **Access information from the Office of the Chief Counsel via the Internet at <I>http—** //www.phmsa.dot.gov.
  - (3) **Send a letter, with your return address and a daytime telephone number, to—** Office of the Chief Counsel, Pipeline and Hazardous Materials Safety Administration, Attn: PHC-10, U.S. Department of Transportation, East Building, 1200 New Jersey Avenue, SE., Washington, DC 20590-0001.
  - (4) Contact the Office of the Chief Counsel for a copy of applications for preemption determinations, waiver of preemption determinations, and inconsistency rulings received by PHMSA before February 1, 1997.

## Notes

### Amendments

[70 FR 56087, Sept. 23, 2005, as amended at 72 FR 55682, Oct. 1, 2007; 76 FR 56310, Sept. 13, 2011]

### Authority

Authority: 49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97.

### Source

Source: 67 FR 42951, June 25, 2002, unless otherwise noted.

### Amendments

[70 FR 56087, Sept. 23, 2005, as amended at 72 FR 55682, Oct. 1, 2007; 76 FR 56310, Sept. 13, 2011]