The National Board of Boiler and Pressure Vessel Inspectors (NBBI) — Hazardous Materials Safety Interpretation

Page 11200 New Jersey Avenue, SE Washington, DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration May 18, 2026 Mr. Luis Ponce The National Board of Boiler and Pressure Vessel Inspectors (NBBI) 1055 Crupper Avenue Columbus, OH 43229-1183 Reference No. 25-0153 Dear Mr. Ponce: This letter is in response to your November 19, 2025 email requesting clarification on how the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) apply to the repair or modification of specification cargo tanks performed by a repair facility holding a valid National Board Certificate of Authorization for use of the National Board “R” stamp. Specifically, you seek clarification on the applicability of the associated National Board Inspection Code (NBIC). We have paraphrased and answered your questions as follows: Q1. Does § 180.413(a)(1) require each repair, modification, stretching, or rebarrelling of a specification cargo tank performed by the repair facility to be performed in accordance with the NBIC, including the application of the “R” symbol stamp and the signing of the applicable Form “R” Report? A1. No. Section 180.413(a)(1) sets standards for the repair facility performing the work unless otherwise excepted. Q2. Does § 180.413(a)(1) require each repair, modification, stretching, or rebarrelling of a specification cargo tank be performed in accordance with the edition of the NBIC in effect at the time the work is performed?#

Page 2A2. In § 180.413(a)(1), the language “in effect at the time the work is performed” refers to the edition of the NBIC incorporated by reference into the HMR at the time the work is performed (see § 171.7(x)(1)). At the time of this writing, that is the 1992 edition. However, there are exceptions in §§ 180.413(a)(1)(i), (ii), and (iii). I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division#

Page 3Cardez, E. 25-0153 From: INFOCNTR (PHMSA) To: Baker, Yul (PHMSA) Cc: Hazmat Interps Subject: FW: Letter of Interpretation Request Date: Wednesday, November 19, 2025 13:20:02 Attachments: image001.png Hi Yul, Please see the below interpretation request. Let me know if you need anything, -Breanna From: Luis Ponce <LPonce@nationalboard.org> Sent: Wednesday, November 19, 2025 1:09 PM To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov> Subject: Letter of Interpretation Request You don't often get email from lponce@nationalboard.org. Learn why this is important CAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links or open attachments unless you recognize the sender and know the content is safe. Greetings, I am submitting this inquiry for your consideration about a requirement in the §49CFR 180.413 a) 1). Statement of Need: There is confusion in the industry about a requirement in the referenced paragraph above that reads in part, “…each repair, modification…of a specification cargo tank must be performed by a repair facility holding a valid National Board Certificate of Authorization for use of the National Board “R” stamp and must be made in accordance with the edition of the National Board Inspection Code in effect at the time the work is performed.” Background: One DOT representative stated this paragraph is not correct because there is no subsequent ‘IBR’ included after the standard reference, the NBIC, like there is in 180.413 a) 6) for MC 330 and MC 331 cargo tanks. However, another DOT representative disagrees and said the 180.413 a) 1) paragraph is correct. In addition, the year edition of the NBIC in the §171.7 is 1992 but this differs from the requirement in the statement of#

Page 4need (bold and underlined text). Question 1: Is it the intent that §49CFR 180.413 a) 1) requires each repair, modification, stretching, or rebarrelling of a specification cargo tank must be performed in accordance with the NBIC, including stamping the “R” symbol stamp and signing the applicable Form “R” Report? Question 2: Is it the intent that §49CFR 180.413 a) 1) requires each repair, modification, stretching, or rebarrelling of a specification cargo tank must be performed in accordance with the edition of the NBIC in effect at the time the work is performed? Regards, Luis Ponce Manager of Technical Services The National Board of Boiler and Pressure Vessel Inspectors 1055 Crupper Avenue Columbus, Ohio 43229-1183 Email: lponce@nationalboard.org Phone: 614-431-3201 Office Fax: 614-847-1828#