Skip to main content
Notice2026-18346

Gexcon U.S., Inc.'s Petition for EFFECTS Version 12.2.0 as an Alternative Model for Calculating the Vapor-Gas Dispersion Exclusion Zone

Primary source

Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.

Published
September 9, 2026

Issuing agencies

Transportation DepartmentPipeline and Hazardous Materials Safety Administration

Abstract

PHMSA is publishing this notice and a draft letter of decision to solicit public comment on a petition for approval that would authorize the use of an alternate flammable vapor-gas dispersion model in connection with the siting of liquefied natural gas (LNG) facilities.

Full Text

<html>
<head>
<title>Federal Register, Volume 91 Issue 173 (Wednesday, September 9, 2026)</title>
</head>
<body><pre>
[Federal Register Volume 91, Number 173 (Wednesday, September 9, 2026)]
[Notices]
[Pages 57446-57447]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-18346]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

[Docket No. PHMSA-2024-0164]


Gexcon U.S., Inc.'s Petition for EFFECTS Version 12.2.0 as an 
Alternative Model for Calculating the Vapor-Gas Dispersion Exclusion 
Zone

AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), 
Department of Transportation (DOT).

ACTION: Notice.

-----------------------------------------------------------------------

SUMMARY: PHMSA is publishing this notice and a draft letter of decision 
to solicit public comment on a petition for approval that would 
authorize the use of an alternate flammable vapor-gas dispersion model 
in connection with the siting of liquefied natural gas (LNG) 
facilities.

DATES: Submit any comments regarding the petition by October 9, 2026.

ADDRESSES: Comments should reference the docket number for the petition 
request and may be submitted in one of the following ways:
    <bullet> E-Gov Web: <a href="http://www.regulations.gov">www.regulations.gov</a>. This site allows the 
public to enter comments on any Federal Register Notice issued by any 
agency. Follow the online instructions for submitting comments.
    <bullet> Mail: Docket Management System: U.S. Department of 
Transportation, 1200 New Jersey Avenue SE, West Building Ground Floor, 
Room W12-140, Washington, DC 20590-0001.
    <bullet> Hand Delivery: DOT Docket Management System: West Building 
Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, between 9:00 
a.m. and 5:00 p.m. EST, Monday through Friday, except Federal holidays.
    <bullet> Fax: 202-493-2251.
    <bullet> Instructions: You should identify the docket number for 
the petition request you are commenting on at the beginning of your 
comments. If you submit your comments by mail, please submit two 
copies. To receive confirmation that PHMSA has received your comments, 
please include a self-addressed stamped postcard. Internet users may 
submit comments at <a href="http://www.regulations.gov">www.regulations.gov</a>.
    <bullet> Note: There is a privacy statement published; to review 
the statement, go to <a href="http://www.regulations.gov">www.regulations.gov</a>, scroll down to the bottom 
left to click ``Privacy & Security Notice.'' Comments, including any 
personal information provided, are posted without changes or edits to 
<a href="http://www.regulations.gov">www.regulations.gov</a>.
    <bullet> Confidential Business Information: Confidential Business 
Information (CBI) is commercial or financial information that is both 
customarily and actually treated as private by its owner. Under the 
Freedom of Information Act (5 U.S. Code 552), CBI is exempt from public 
disclosure. If your comments in response to this notice contain 
commercial or financial information that is customarily treated as 
private, which you actually treat as private, and that is relevant or 
responsive to this notice, it is important that you clearly designate 
the submitted comments as CBI. Pursuant to 49 CFR 190.343, you may ask 
PHMSA to provide confidential treatment to information you give to the 
agency by taking the following steps: (1) mark each page of the 
original document submission containing CBI as ``Confidential''; (2) 
send PHMSA a copy of the original document with the CBI deleted along 
with the original, unaltered document; and (3) explain why the 
information you are submitting is CBI. Submissions containing CBI 
should be sent to Mr. Lee Cooper, 1200 New Jersey Avenue SE, DOT: 
PHMSA-PHP-80, Washington, DC 20590-0001. Any commentary PHMSA receives 
that is not specifically designated as CBI will be placed in the public 
docket.
    <bullet> Privacy Act: DOT may solicit comments from the public 
regarding certain general notices. DOT posts these comments, without 
edits, including any personal information the commenter provides, to 
<a href="http://www.regulations.gov">www.regulations.gov</a>, as described in the system of records notice (DOT/
ALL-14 FDMS), which can be reviewed at <a href="http://www.dot.gov/privacy">www.dot.gov/privacy</a>.
    <bullet> Docket: For access to the docket to read background 
documents or comments received, go to <a href="http://www.regulations.gov">www.regulations.gov</a>. Follow the 
online instructions for accessing the dockets. Alternatively, you may 
review the documents in person at the street address listed above.

FOR FURTHER INFORMATION CONTACT: 
    General: Mr. Lee Cooper by phone at 202-913-3171 or by email at 
<a href="/cdn-cgi/l/email-protection#1e727b7b307d71716e7b6c5e7a716a30797168"><span class="__cf_email__" data-cfemail="2b474e4e054844445b4e596b4f445f054c445d">[email&#160;protected]</span></a>.
    Technical: Mr. Thach Nguyen by phone at 909-262-4464 or by email at 
<a href="/cdn-cgi/l/email-protection#f6829e97959ed892d89891838f9398b6929982d8919980"><span class="__cf_email__" data-cfemail="6115090002094f054f0f061418040f21050e154f060e17">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: PHMSA is evaluating a petition from Gexcon 
U.S., Inc. (Gexcon) requesting approval, pursuant to 49 CFR 190.9, 
authorizing use of its EFFECTS v12.2.0 (EFFECTS v12.2) software as an 
alternate model for calculating, pursuant to 49 CFR 193.2059, the 
flammable vapor-gas dispersion exclusion zones for 49 CFR part 193-
regulated LNG facilities.

[[Page 57447]]

    PHMSA's safety standards for the siting of LNG facilities are found 
in subpart B of 49 CFR part 193. Section 193.2059 requires that each 
LNG container and LNG transfer system must have a flammable vapor-gas 
dispersion exclusion zone, defined as the area surrounding an LNG 
facility in which an operator or government agency legally controls all 
activities. The exclusion zone is intended to protect the public from 
the flammable vapor gas and direct exposure to the flame in the event 
of a release or ignition, respectively. In accordance with 49 CFR 
193.2059(a), an LNG operator must calculate vapor-gas dispersion 
exclusion zones using either the DEGADIS 2.1 Dense Gas Dispersion model 
or FEM3A model. Section 193.2059 also states that the Administrator (or 
his delegate) may, pursuant to the procedures set forth in 49 CFR 
190.9, approve the use of alternative vapor-gas dispersion models that 
take into account the same physical factors as those considered in the 
development of the DEGADIS 2.1 and FEM3A models, and which have been 
validated by experimental test data.
    On December 11, 2023, Gexcon petitioned PHMSA for approval of its 
EFFECTS v12.2 software as an alternate model for calculating the LNG 
flammable vapor-gas dispersion exclusion zones. The petition and draft 
letter of decision for EFFECTS v12.2 are available for review and 
public comment in Docket No. PHMSA-2024-0164.
    Before issuing a final decision on Gexcon's petition, PHMSA will 
evaluate all comments received on or before the comment closing date. 
Comments received after the closing date will be evaluated if it is 
possible to do so without incurring additional expenses or delay. PHMSA 
will consider each relevant comment we receive in making our final 
decision to grant or deny this request.

    Issued in Washington, DC, under authority delegated in 49 CFR 
1.97.
Thomas Correll,
Associate Administrator for Pipeline Safety.
[FR Doc. 2026-18346 Filed 9-8-26; 8:45 am]
BILLING CODE 4910-60-P


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>
Indexed from Federal Register on September 9, 2026.

This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.