# Remora Carbon — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 24-0126
- **title:** Remora Carbon — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2025-01-03
- **effective on:** Not available
- **summary:** 24-0126 response to Remora Carbon concerning 171.1.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-24-0126.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-24-0126.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-24-0126
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-01/240126.pdf
**body:**

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U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
January 3, 2025
Mr. Paul Gross
CEO
Remora Carbon
13685 Otterson Ct
Livonia, MI 48150
Reference No. 24-0126
Dear Mr. Gross:
This letter is in response to your December 20, 2024, email requesting clarification of the
Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) regarding the applicability of
the HMR to a new technology your company has developed. In your email, you describe a
device designed to capture carbon dioxide that will be attached to a locomotive. Further, you
mention that in a previously issued letter of interpretation (LOI; Reference No. 21-0078),
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PHMSA was asked about the application of similar technology to motor vehicles. In your email,
you ask whether your carbon capture device is subject to the HMR when installed on a
locomotive.
Based on the information you have provided, the answer is no. Section 171.1(b) and (c) state that
the requirements of the HMR apply to each person who offers a hazardous material for
transportation in commerce or transports a hazardous material in commerce. It is the opinion of
this Office that auxiliary equipment attached to a locomotive with the intent of reducing carbon
emissions is not considered to be “in commerce.
” Therefore, the requirements of the HMR are
not applicable to your device.
However, please be aware that there may be applicable requirements from other Federal agencies
such as the Federal Railroad Administration, who can be reached at (202) 493-6024, and the
Environmental Protection Agency (EPA), who can be reached at (734) 214-4333.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Steven Andrews
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
1 https://www.phmsa.dot.gov/regulations/title49/interp/21-0078

<<<PAGE 2>>>

24-0126
Jones, Jessie Jane (PHMSA)
Andrews
From: Andrews, Steven (PHMSA)
Sent: Friday, December 20, 2024 2:33 PM
To: Jones, Jessie Jane (PHMSA)
Cc: Dodd, Alice (PHMSA); Nickels, Matthew (PHMSA)
Subject: Follow Up Flag: Follow up
Flag Status: Flagged
FW: Remora — PHMSA Letter of Interpretation Request
Jessie,
I forgot alice is out today. Can you flip this email around into a interp for me real quick with a number? Shoot it to me
and assign it to me in Filemaker.
Thanks!
Steven
From: Andrews, Steven (PHMSA) <steven.andrews@dot.gov>
Sent: Friday, December 20, 2024 2:02 PM
To: Dodd, Alice (PHMSA) <Alice.Dodd@dot.gov>
Cc: Nickels, Matthew (PHMSA) <Matthew.Nickels@dot.gov>
Subject: Fw: Remora — PHMSA Letter of Interpretation Request
Alice,
Can you quickly assign this an interp number and assign it to me? Let me know what the number is or send me the
incoming with the interp number on it.
Thanks!
Steven
From: Paul Gross <paul@remoracarbon.com>
Sent: Friday, December 20, 2024 1:59:51 PM
To: Andrews, Steven (PHMSA) <steven.andrews@dot.gov>
Cc: clay@lowercasellc.com <clay@lowercasellc.com>
Subject: Remora — PHMSA Letter of Interpretation Request
You don't often get email from paul@remoracarbon.com. 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.
Hi Steven,
As Clay Dumas discussed with you, Remora is building a carbon capture system for locomotives. Our carbon capture
system will be packaged on a tender car behind the locomotive, and will attach to the locomotive's exhaust outlet. It will
filter carbon dioxide from the locomotive's exhaust and store the captured CO2 in a tank. We are requesting a letter of
interpretation to guide our design.
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The material being stored is primarily (> 95%) liquid CO2, with small amounts of gaseous N2, O2, and Ar. We will be
storing the CO2 in a 20' CO2 ISO container or similar, which will be packaged on the tender car along with the CO2
capture system. A 20' ISO container can hold approximately 20 MT of CO2. The CO2 will be compressed to 20 bar and
refrigerated to -40 degrees Celsius.
Our system will also reduce the locomotive's criteria pollutant (e.g. NOx, PM) emissions by 90%, and this reduction will
take place ahead of the CO2 capture system.
I am happy to answer any questions you have and look forward to hearing back from you!
Thanks,
Paul
--
Paul Gross
CEO, Remora
415-866-8851
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