(a) General authority. An Administrator may initiate an inspection or investigation to determine compliance with Federal hazardous material transportation law, or a regulation, order, special permit, or approval prescribed or issued under the Federal hazardous material transportation law, or any court decree or order relating thereto.

(b) Inspections and investigations. Inspections and investigations are conducted by designated agents of the Secretary who will, upon request, present their credentials for examination. Such an agent is authorized to:

(1) Administer oaths and receive affirmations in any matter under investigation.

(2) Gather information by any reasonable means, including, but not limited to, gaining access to records and property (including packages), interviewing, photocopying, photographing, and video- and audio-recording in a reasonable manner.

(3) Serve subpoenas for the production of documents or other tangible evidence if, on the basis of information available to the agent, the evidence is relevant to a determination of compliance with the Federal hazardous material transportation law, regulation, order, special permit, or approval prescribed or issued under the Federal hazardous material transportation law, or any court decree or order relating thereto. Service of a subpoena shall be in accordance with the requirements of the agent's operating administration as set forth in 14 CFR 13.3 (Federal Aviation Administration); 49 CFR 209.7 (Federal Railroad Administration), 49 U.S.C. 502(d), 5121(a) (Federal Motor Carrier Safety Administration), and 49 CFR 105.45-105.55 (Pipeline and Hazardous Materials Safety Administration).