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Section §173.436: Exempt material activity concentrations and exempt consignment activity limits for radionuclides

Below are the available interpretations and guidance for the given section. To return to the list of parts, use the Parts link above. If you do not see any guidance or interpretation information below, that means there is none available for the given part/section. Return to the search page to browse additional regulations sections.

PHMSA has published several Frequently Asked Questions (FAQ) documents on regulatory topics. Please review our FAQ documents below:

Additionally PHMSA has Hazardous Materials FAQs based on letters of interpretation on the following topics:

This section of the website provides the ability to find regulations information including regulations parts, content of sections, and interpretations for regulations sections. Below is a list of parts, identified by the part number and subject. To browse sections by part, click on the subject link below. You will be taken to the eCFR website to view sections for a part.

A written regulatory interpretation, response to a question, or an opinion concerning a pipeline safety issue may be obtained by submitting a written request to the Office of Pipeline Safety (PHP–30), PHMSA, U.S. Department of Transportation, 1200 New Jersey Avenue SE., Washington, DC 20590–0001 or at the email address: In addition to email address, the requestor must include his or her return address and should also include a daytime telephone number. Requests should be submitted at least 120 days before the time the requestor needs a response.

Note: electronic submission is provided as alternative to the 49 CFR Part 190.11(b) mail-in requirement.

The regulations text of the section can be found on the eCFR website. To view the regulations text, use the link below. For assistance, please send an email to

View section 173.436 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
22-0014 I.C.E. Service Group & SPS Strategic Packaging Systems Mr. Kurt Colborn View
22-0029 Belshire Environmental Services Inc. Bear Bridges View
20-0073 John B. Woodbury View
20-0031 Mark B. Hawk View
18-0088 Settoon Towing Nicholas Kohnke View
18-0014 Nuclear Energy Institute Janet Schlueter View
18-0033 Occupational Services Inc. Linda Bray View
18-0030 Lighting Technologies International, LLC Joe Rodriguez View
17-0114 PHI.Inc Mr. Terry Myer View
06-0274 HMTC Training & Consulting Mr. Philip C. Rieke View
05-0240 Triumvirate Environmental Mr. Rick Foote View
07-0210 University of California, Los Angeles Ms. Carol S. Marcus View
13-0210 Baker Hughes Houston Technology Center Mr. James K. Elrod View
16-0016 U.S. Customs and Border Protection Mr. Jason Hart View
06-0003 Thompson & Simmons, PLLC Mr. Charles T. Simmons View
14-0086 Fairview Hospital Ms. Christina D. Cahill CNMT. RT (R) View
16-0109 Spectrum Techniques Mr. Daniel Sims View
13-0080 Detector Electronics Corporation Mr. Lee R. Zwiefelhofer View
11-0126 Sandia National Laboratories Mr. Michael W. Enghauser View
10-0082 Osram Sylvania Mr. John Fichera View