Department of Transportation
Pipeline and Hazardous Materials Safety Administration
- 49 CFR Part 180
- [Docket No. PHMSA-2025-0103 (HM-268O)]
- RIN 2137-AG17
AGENCY:
Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT).
ACTION:
Final rule.
SUMMARY:
This final rule removes undue regulatory burdens by adopting the provisions of U.S. Department of Transportation (DOT) special permit (SP) 14175 to authorize a 10-year requalification period and the ultrasonic examination (UE) testing method for DOT specification 3A and 3AA cylinders in flammable and non-flammable, nonpoisonous gas service. This adoption reflects advances in testing technology and will relieve stakeholders of the burden of performing more frequent cylinder requalification.
DATES:
This final rule is effective September 3, 2026.
FOR FURTHER INFORMATION CONTACT:
Ryan Larson, Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration (PHMSA), 1200 New Jersey Avenue SE, Washington, DC 20590, 202-366-8553, ryan.larson@dot.gov.
I. PHMSA Action
A. What action is PHMSA taking in this final rule?
PHMSA is adopting the provisions of DOT SP 14175 into the Hazardous Materials Regulations (HMR; 49 CFR parts 171-180) by adding new paragraph (b)(2) to 49 CFR 180.209. This change will authorize a 10-year requalification interval (rather than five years) when either UE testing or hydrostatic testing with visual inspection is used for DOT specification 3A and 3AA cylinder bundles in flammable and non-flammable, nonpoisonous gas service.
B. Does this action apply to me?
Effective 30 days after publication of this final rule, holders of DOT SP 14175 will no longer need a special permit to requalify DOT specification 3A or 3AA cylinder bundles used in flammable and non-flammable, nonpoisonous gas service using UE.
C. Why is PHMSA taking this action?
PHMSA is taking this action in response to commenter feedback and to provide relief to stakeholders by allowing longer requalification intervals for the specified cylinder types when used in certain types of service. Allowing for the use of a 10-year requalification interval with UE testing or hydrostatic testing with visual inspection will reduce costs and provide greater efficiencies while also maintaining safety. PHMSA is also taking this action as part of its ongoing review of special permits that are appropriate for adoption into the HMR based on their safety record and positive impact on stakeholders.
II. Summary of Comments Received in Response to the Notice of Proposed Rulemaking
PHMSA published a notice of proposed rulemaking (NPRM), cited as HM-268O, to gather feedback on adopting DOT SP 14175 into the HMR.[1] Please refer to the NPRM for background and discussion of the proposed changes.
The following table alphabetically lists commenters to the NPRM:
| Commenter name | Docket No. |
|---|---|
| Compressed Gas Association (CGA) | PHMSA-2025-0103-0003 |
| Dangerous Goods Advisory Council | PHMSA-2025-0103-0004 |
Both commenters supported adopting DOT SP 14175 into the HMR. However, CGA had additional questions or suggestions related to the NPRM proposal.
First, CGA argued that if UE and hydrostatic testing are treated as equals, the NPRM proposal to add text to Table 1 to Paragraph (a) in 49 CFR 180.209 and 49 CFR 180.209(b)(2) requiring UE to be performed by a valid Requalification Identification Number (RIN) holder for DOT 3A and 3AA cylinders is unnecessary. PHMSA concurs with CGA's comment that the proposed text requiring a valid RIN holder to perform UE could cause confusion since no similar requirement is stated for the other test methods—such as hydrostatic pressure testing. In addition, PHMSA notes that 49 CFR 180.205 already requires a valid RIN holder for all requalification functions. PHMSA is therefore removing the text in Table 1 to Paragraph (a) and Paragraph (b)(2) of 49 CFR 180.209 ( printed page 49355) specific to valid RIN holders in this final rule.
Second, CGA noted that a prior rulemaking (HM-219D) authorized UE for certain cylinders based on a petition for rulemaking (P-1727) to incorporate by reference the UE testing procedures in CGA C-20 Requalification Standard for Metallic, DOT and TC 3-series Gas Cylinders and Tubes Using Ultrasonic Examination, Second Edition.[2] CGA noted that the HM-219D final rule failed to identify all DOT 3-series cylinders in Table 1 to Paragraph (a) in 49 CFR 180.209 as being eligible for UE and—unintentionally—only authorized UE for DOT 3T specification cylinders and exemption or special permit cylinders. PHMSA acknowledges CGA's comment that UE should be authorized for the additional DOT 3-series cylinders as was requested in the CGA petition P-1727. While PHMSA is not incorporating these revisions in this final rule, PHMSA will consider this suggestion in a future rulemaking.
Third, CGA suggested that PHMSA adopt provisions from additional special permits—such as DOT SP 20341—which authorize UE for additional cylinder types. CGA noted that in doing so, PHMSA should update the reference for UE from CGA C-20-2014 to the more recent CGA C-20-2021, as proposed in CGA petition P-1766. While PHMSA is not incorporating these revisions in this final rule, PHMSA will consider this suggestion in a future rulemaking.
For these reasons, PHMSA concludes that the revisions will maintain appropriate levels of safety and authorize reasonable flexibilities and is therefore adopting the provisions of DOT SP 14175 into 49 CFR 180.209 in this final rule. PHMSA does not expect these revisions to have substantial adverse impact on safety.
III. Regulatory Analysis and Notices
A. Legal Authority
This final rule is published under the authority of the Secretary of Transportation as set forth in the Federal Hazardous Materials Transportation laws (49 U.S.C. 5101 et seq.) and delegated to the PHMSA Administrator pursuant to 49 CFR 1.97.
B. Executive Order 12866; Regulatory Planning and Review
Executive Order (E.O.) 12866 ( Regulatory Planning and Review), as implemented by 49 CFR part 5, subpart B, requires agencies to regulate in the “most cost-effective manner,” to make a “reasoned determination that the benefits of the intended regulation justify its costs,” and to develop regulations that “impose the least burden on society.” [3] In arriving at those conclusions, E.O. 12866 requires that agencies should consider “both quantifiable measures . . . and qualitative measures of costs and benefits that are difficult to quantify” and “maximize net benefits . . . unless a statute requires another regulatory approach.” E.O. 12866 also requires that “agencies should assess all costs and benefits of available regulatory alternatives, including the alternative of not regulating.” Pursuant to 49 CFR part 5, subpart B, PHMSA and other Operating Administrations must generally choose the “least costly regulatory alternative that achieves the relevant objectives” unless required by law or compelling safety need. In addition, 49 CFR part 5, subpart B specifies that regulations should generally “not be issued unless their benefits are expected to exceed their costs.”
E.O. 12866 and 49 CFR part 5, subpart B also require that PHMSA submit “significant regulatory actions” to the Office of Information and Regulatory Affairs (OIRA) within the Executive Office of the President's Office of Management and Budget (OMB) for review. This final rule is not a significant regulatory action pursuant to E.O. 12866 and has not been designated as a “major rule” as defined by the Congressional Review Act (5 U.S.C. 801 et seq.).
PHMSA has complied with the requirements in E.O. 12866 as implemented by 49 CFR part 5, subpart B, and determined this final rule will result in cost savings by reducing regulatory burdens and regulatory uncertainty for affected entities by providing longer cylinder requalification intervals with an alternative test method that has proven to be more accurate and more efficient. PHMSA expects that cost savings will result in reduced costs for the public to whom those entities generally transfer a portion of their compliance costs.
C. Executive Orders 14192 and 14219
PHMSA has determined that this final rule is an E.O. 14192 ( Unleashing Prosperity Through Deregulation ) deregulatory action.[4] PHMSA finds the total costs of the rule on the regulated community will be less than zero. This final rule does not implicate any of the factors identified in section 2(a) of E.O. 14219 ( Ensuring Lawful Governance ) indicative of a regulation that is “unlawful . . . [or] that undermine[s] the national interest.” [5]
D. Energy-Related Executive Orders 13211, 14154, and 14156
PHMSA has analyzed this final rule in accordance with the principles and criteria contained in E.O. 14156 ( Declaring a National Energy Emergency) and E.O. 14154 ( Unleashing American Energy ).[6] The President has declared a national emergency to address America's inadequate energy development production, transportation, refining, and generation capacity and asserted a Federal policy to unleash American energy by ensuring access to abundant supplies of reliable, affordable energy from, inter alia, the removal of “undue burden[s]” on the identification, development, or use of domestic energy resources. PHMSA finds this final rule to be consistent with E.O. 14156 and E.O. 14154 because it will not hinder or unduly burden the transportation or production of energy or energy-related products.
In addition, this final rule is not a “significant energy action” under E.O. 13211 ( Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use ), which requires Federal agencies to prepare a Statement of Energy Effects for any “significant energy action.” [7] Because this final rule is not a significant action under E.O. 12866, it will not have a significant adverse effect on supply, distribution, or energy use; accordingly, OIRA has not designated this final rule as a significant energy action.
E. Executive Order 13132: Federalism
PHMSA analyzed this final rule in accordance with the principles and criteria contained in E.O. 13132 ( Federalism) and the Presidential Memorandum ( Preemption) published in the Federal Register on May 22, 2009.[8] E.O. 13132 requires agencies to assure meaningful and timely input by State and local officials in the development of regulatory policies that may have “substantial direct effects on the States, on the relationship between the National Government and the States, or on the distribution of power and ( printed page 49356) responsibilities among the various levels of government.” The Federal Hazardous Materials Transportation Law contains an express preemption provision at 49 U.S.C. 5125(b) that preempts State, local, and Tribal requirements on certain covered subjects, unless the non-Federal requirements are “substantively the same” as the Federal requirements, including the following:
(1) The designation, description, and classification of hazardous material;
(2) The packing, repacking, handling, labeling, marking, and placarding of hazardous material;
(3) The preparation, execution, and use of shipping documents related to hazardous material and requirements related to the number, contents, and placement of those documents;
(4) The written notification, recording, and reporting of the unintentional release in transportation of hazardous material; and
(5) The design, manufacture, fabrication, inspection, marking, maintenance, recondition, repair, or testing of a packaging or container represented, marked, certified, or sold as qualified for use in transporting hazardous material in commerce.
This final rule addresses items covered in Paragraph (5) above and will preempt State, local, and Tribal requirements not meeting the “substantively the same” standard. Although the final rule may operate to preempt some State requirements, it will not impose any regulation that has substantial direct effects on the States, the relationship between the National Government and the States, or the distribution of power and responsibilities among the various levels of government. The preemptive effect of the regulatory amendments in this final rule is limited to the minimum level necessary to achieve the objectives of the Federal Hazardous Materials Transportation Law. Therefore, the consultation and funding requirements of E.O. 13132 do not apply.
F. Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires Federal agencies to conduct a Final Regulatory Flexibility Analysis (FRFA) for a final rule that has been subject to notice-and-comment rulemaking under the APA unless the agency head certifies that the final rule in the rulemaking will not have a significant economic impact on a substantial number of small entities. E.O. 13272 ( Proper Consideration of Small Entities in Agency Rulemaking ) obliges agencies to establish procedures promoting compliance with the Regulatory Flexibility Act. DOT posts information on a dedicated web page to help small businesses understand and navigate Federal regulatory processes.[9] PHMSA developed this final rule in accordance with E.O. 13272 and DOT implementing guidance to ensure compliance with the Regulatory Flexibility Act. Because the final rule is expected to reduce burdens, PHMSA certifies that it does not have a significant impact on a substantial number of small entities.
G. Unfunded Mandates Reform Act of 1995
The Unfunded Mandates Reform Act (UMRA, 2 U.S.C. 1501 et seq.) requires agencies to assess the effects of Federal regulatory actions on State, local, and Tribal governments, and the private sector. For any proposed or final rule that includes a Federal mandate that may result in the expenditure by State, local, and Tribal governments, in the aggregate of $100 million or more (in 1996 dollars) in any given year, the agency must prepare, among other things, a written statement that qualitatively and quantitatively assesses the costs and benefits of the Federal mandate.
This final rule does not impose unfunded mandates under UMRA because it does not result in costs of $100 million or more (in 1996 dollars) per year for either State, local, or Tribal governments, or to the private sector.
H. National Environmental Policy Act
PHMSA has analyzed this rule pursuant to the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.) and has determined it is categorically excluded under 23 CFR 771.117(c)(20), which applies to the promulgation of rules, regulations, and directives. Under Section 9 of DOT Order 5610.1D, PHMSA may apply a categorical exclusion (CE) established in another Operating Administration's procedures. PHMSA followed the requirements outlined in DOT Order 5610.1D to apply the Federal Highway Administration's CE to this deregulatory action. PHMSA has determined no unusual circumstances are present under 23 CFR 771.117(b). PHMSA's Categorical Exclusion Determination memo for this action is available on PHMSA's website.[10]
I. Executive Order 13175
PHMSA analyzed this final rule according to the principles and criteria in E.O. 13175 (Consultation and Coordination with Indian Tribal Governments) and DOT Order 5301.1A (Department of Transportation Tribal Consultation Policies and Procedures).[11] Executive Order 13175 requires agencies to assure meaningful and timely input from Tribal government representatives in the development of rules that significantly or uniquely affect Tribal communities by imposing “substantial direct compliance costs” or “substantial direct effects” on such communities or the relationship or distribution of power between the Federal Government and Tribes.
PHMSA assessed the impact of the final rule and determined it would not significantly or uniquely affect Tribal communities or Indian Tribal governments. The rulemaking's regulatory amendments have a broad, national scope; therefore, this final rule will not significantly or uniquely affect Tribal communities, much less impose substantial compliance costs on Tribal governments or mandate Tribal action. For these reasons, PHMSA has concluded the funding and consultation requirements of E.O. 13175 and DOT Order 5301.1A do not apply.
J. Paperwork Reduction Act
The Paperwork Reduction Act (44 U.S.C. 3501 et seq.) and its implementing regulations at 5 CFR 1320.8(d) requires PHMSA to provide interested members of the public and affected agencies with an opportunity to comment on information collection and recordkeeping requests. This rulemaking would not create, amend, or rescind any existing information collections.
However, this rulemaking eliminates the need for persons to renew a special permit, resulting in a decrease in paperwork burden for special permit holders. PHMSA estimates the reduction in information collection burden as follows:
OMB Control No. 2137-0051: Rulemaking, Special Permits, and Preemption Requirements.
Decrease in Annual Number of Respondents: 30.
Decrease in Annual Responses: 30.
Decrease in Annual Burden Hours: 45.
Decrease in Annual Burden Cost: $0.
Please direct your requests for a copy of this information collection to Steven Andrews, Office of Hazardous Materials ( printed page 49357) Standards (PHH-12), Pipeline and Hazardous Materials Safety Administration, 1200 New Jersey Avenue SE, 2nd Floor, Washington, DC 20590-0001.
K. Executive Order 13609 and International Trade Analysis
E.O. 13609 ( Promoting International Regulatory Cooperation ) [12] requires agencies consider whether the impacts associated with significant variations between domestic and international regulatory approaches are unnecessary or may impair the ability of American business to export and compete internationally.[13] In meeting shared challenges involving health, safety, labor, security, environmental, and other issues, international regulatory cooperation can identify approaches that are at least as protective as those that are or would be adopted in the absence of such cooperation. International regulatory cooperation can also reduce, eliminate, or prevent unnecessary differences in regulatory requirements.
Similarly, the Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal agencies from establishing any standards or engaging in related activities that create unnecessary obstacles to the foreign commerce of the United States. For purposes of these requirements, Federal agencies may participate in the establishment of international standards, so long as the standards have a legitimate domestic objective, such as providing for safety, and do not operate to exclude imports that meet this objective. The statute also requires consideration of international standards and, where appropriate, that they be the basis for U.S. standards.
PHMSA engages with international standards setting bodies to protect the safety of the American public. PHMSA has assessed the effects of the final rule and has determined that its regulatory amendments would not cause unnecessary obstacles to foreign trade.
L. Cybersecurity and Executive Order 14028
E.O. 14028 ( Improving the Nation's Cybersecurity ) directed the Federal Government to improve its efforts to identify, to deter, and to respond to “persistent and increasingly sophisticated malicious cyber campaigns.” [14] PHMSA has considered the effects of the final rule and has determined that its regulatory amendments would not materially affect the cybersecurity risk profile for affected entities.
M. Privacy Act Statement
In accordance with 5 U.S.C. 553(c), DOT solicits comments from the public to inform its rulemaking process better. DOT posts these comments, without edit, including any personal information the commenter provides, to www.regulations.gov, as described in the system of records notice (DOT/ALL-14 FDMS), which can be reviewed at https://www.dot.gov/privacy. DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000, or on DOT's website at https://www.dot.gov/privacy.
List of Subjects in 49 CFR Part 180
- Hazardous materials transportation
- Motor carriers
- Motor vehicle safety
- Packaging and containers
- Reporting
- Recordkeeping requirements
In consideration of the foregoing, PHMSA amends 49 CFR Chapter I as follows:
PART 180—CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS
1. The authority citation for part 180 continues to read as follows:
2. In § 180.209, revise paragraphs (a) and (b) to read as follows:
(a) Periodic qualification of cylinders. Each specification cylinder that becomes due for periodic requalification, as specified in the following table, must be requalified and marked in conformance with the requirements of this subpart. Requalification records must be maintained in accordance with § 180.215. Table 1 follows:
| Specification under which cylinder was made | Minimum test pressure (psig) 2 | Requalification period (years) |
|---|---|---|
| 3 | 3000 psig | 5. |
| 3A, 3AA | 5/3 times service pressure, except non-corrosive service ( see § 180.209(g)), or UE 3 | 5, 10, or 12 ( see § 180.209(b), (f), (h), and (j)). |
| 3AL | 5/3 times service pressure | 5 or 12 ( see § 180.209(j) and (m) 4 ). |
| 3AX, 3AAX | 5/3 times service pressure | 5. |
| 3B, 3BN | 2 times service pressure ( see § 180.209(g)) | 5 or 10 ( see § 180.209(f)). |
| 3E | Test not required | |
| 3HT | 5/3 times service pressure | 3 ( see §§ 180.209(k) and 180.213(c)). |
| 3T | 5/3 times service pressure or UE 3 | 5. |
| 4AA480 | 2 times service pressure ( see § 180.209(g)) | 5 or 10 ( see § 180.209(h)). |
| 4B, 4BA, 4BW, 4B-240ET | 2 times service pressure, except non-corrosive service ( see § 180.209(g)) | 5, 7, 10, or 12 ( see § 180.209(e), (f), and (j)). |
| 4D, 4DA, 4DS | 2 times service pressure | 5. |
| 4E | 2 times service pressure, except non-corrosive service ( see § 180.209(g)) | 5, 10, or 12 ( see § 180.209(e)). |
| 4L | Test not required | |
| 8, 8AL | 10 or 20 ( see § 180.209(i)). | |
| Exemption or special permit cylinder | See current exemption or special permit, or UE 3 as allowed by CGA C-20 (2014) | See current exemption or special permit. |
| Foreign cylinder ( see § 173.301(j) of this subchapter for restrictions on use) | As marked on cylinder, but not less than 53 of any service or working pressure marking | 5 ( see §§ 180.209(l) and 180.213(d)(2)). |
| 1 Any cylinder not exceeding two inches outside diameter and less than two feet in length is excepted from volumetric expansion test. | ||
| 2 For cylinders not marked with a service pressure, see § 173.301a(b) of this subchapter. ( printed page 49358) | ||
| 3 Minimum test pressure is not applicable to those cylinders and tubes requalified using ultrasonic examination (UE). | ||
| 4 This provision does not apply to cylinders used for carbon dioxide, fire extinguisher, or other industrial gas service. | ||
(b) DOT 3A or 3AA cylinders. (1) A cylinder conforming to specification DOT 3A or 3AA with a water capacity of 56.7 kg (125 lb.) or less that is removed from any cluster, bank, group, rack, or vehicle each time it is filled, may be requalified every ten years instead of every five years, provided the cylinder conforms to all of the following conditions:
(i) The cylinder was manufactured after December 31, 1945.
(ii) The cylinder is used exclusively for air; argon; cyclopropane; ethylene; helium; hydrogen; krypton; neon; nitrogen; nitrous oxide; oxygen; sulfur hexafluoride; xenon; chlorinated hydrocarbons, fluorinated hydrocarbons, liquefied hydrocarbons, and mixtures thereof that are commercially free from corroding components; permitted mixtures of these gases ( see § 173.301(d) of this subchapter); and permitted mixtures of these gases with up to 30 percent by volume of carbon dioxide, provided the gas has a dew point at or below minus (52 °F) at 1 atmosphere.
(iii) [Reserved]
(iv) The cylinder is dried immediately after hydrostatic testing to remove all traces of water.
(v) The cylinder is not used for underwater breathing.
(vi) Each cylinder is stamped with a five-pointed star at least one-fourth of an inch high immediately following the test date.
(2) A cylinder conforming to specification DOT 3A or 3AA with a water capacity of 56.7 kg (125 lb.) or less that is not removed from any cluster, bank, group, rack, or vehicle each time it is filled, may be requalified by either hydrostatic testing and visual inspection described in § 180.205 or by ultrasonic examination (UE) every ten years instead of every five years, provided the cylinder conforms to all of the following conditions:
(i) The cylinder was manufactured after December 31, 1945.
(ii) The cylinder is used exclusively for air; argon; helium; oxygen; nitrogen; neon; tetrafluoromethane (CF4); hydrogen; deuterium; mixtures of hydrogen, argon, helium, oxygen, and/or nitrogen; mixtures of argon, xenon, and/or neon; mixtures of krypton and neon; mixtures of hydrogen, argon, helium, and/or nitrogen; and mixtures containing deuterium, provided all gas mixtures have a dew point at or below minus (52 °F) at 1 atmosphere.
(iii) Carbon dioxide in any concentration cannot be added to cylinders in the bundle.
(iv) Gases that are toxic and/or corrosive cannot be added to cylinders in the bundle.
(v) If requalified by hydrostatic pressure testing, the cylinder is dried immediately after testing to remove all traces of water.
(vi) The cylinder is not used for underwater breathing.
(vii) Each cylinder is stamped with a five-pointed star at least one-fourth of an inch high immediately following the test date.
(3) If, since the last required requalification, a cylinder has not been used exclusively for the gases specifically identified in paragraph (b)(1)(ii) of this section, but currently conforms with all other provisions of paragraph (b)(1) of this section, it may be requalified every 10 years instead of every five years, provided it is first requalified and examined as prescribed by § 173.302a(b)(2), (3) and (4) of this subchapter.
(4) Except as specified in paragraph (b)(3) of this section, if a cylinder, marked with a star, is filled with a compressed gas other than as specified in paragraph (b)(1)(ii) of this section, the star following the most recent test date must be obliterated. The cylinder must be requalified five years from the marked test date, or prior to the first filling with a compressed gas, if the required five-year requalification period has passed.
Issued in Washington, DC, on July 31, 2026, under the authority delegated in 49 CFR 1.97.
Paul J. Roberti,
Administrator, Pipeline and Hazardous Materials Safety Administration.