# Qnergy — Hazardous Materials Safety Interpretation

**Citation:** 23-0043  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2023-08-24

23-0043 response to Qnergy concerning 173.159, 173.220.

## Document text

<<<PAGE 1>>>

1200 New Jersey Avenue, SE
Washington, DC 20590
U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
August 24, 2023
Mr. Allen Peterson
Product Applications Mechanical Engineer
Qnergy
300 W 12th St.
Ogden, UT 84404
Reference No. 23-0043
Dear Mr. Peterson:
This letter is in response to your April 14, 2023, email requesting clarification of the Hazardous
Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to battery-powered equipment
or machinery. In your email, you state that your company offers for transportation stand-alone
battery-powered electrical equipment that provides electricity at remote jobsites when gaseous
fuel is supplied by customers to enable electrical power generation. You also state that the
equipment does not self-contain fuel and is completely purged of all fuel during transport. You
further state that this generator equipment contains an upright, non-spillable, wet battery securely
installed within the equipment’s strong outer enclosure—as well as machinery you describe as a
“refrigerating machine” that uses a hermetically sealed mass of heat transport media (compressed
helium) to enable cooling of the combustor and conversion between heat transfer, pressure work,
motion, and electricity. You request confirmation that this stand-alone battery-powered
electrical equipment as described in your email is excepted from all requirements of the HMR in
compliance with § 173.220.
In accordance with § 173.220(h), shipments made under the provisions of § 173.220 are not
subject to any other requirements of the HMR for transportation by motor vehicle or rail car.
Based on the description in your email, it appears that this stand-alone battery-powered electrical
equipment would meet these provisions. Please note that a battery-powered generator must meet
the requirements specified in § 173.220(c), which states that batteries must be securely installed,
and wet batteries must be fastened in an upright position. Batteries must also be protected
against a dangerous evolution of heat, short circuits, and damage to terminals in conformance
with § 173.159(a) and leakage; or must be removed and packaged separately in accordance with
§ 173.159.
Further, § 173.220(f)(1) states that items containing other hazardous materials that are integral
components of the equipment—and that are necessary for the operation of the equipment, or for
the safety of its operator or passengers— are not otherwise subject to the requirements of the
HMR. Based on your description of the compressed helium contained in the “refrigerating
machine” element of the generator, the “refrigerating machine” would meet this provision.
Please note that the item containing other hazardous materials must be securely installed in the
equipment.

<<<PAGE 2>>>

Lastly, please note that this stand-alone battery-powered electrical equipment may not be
excepted from all other requirements of the HMR when transported by aircraft or vessel. Please
see the provisions in § 173.220(h)(2) and (3) for transportation by aircraft or vessel.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

<<<PAGE 3>>>

Larson
From: INFOCNTR (PHMSA)
To: Dodd, Alice (PHMSA)
Cc: Hazmat Interps
Subject: FW: Qnergy PowerGen - Interpretation Request
Date: Wednesday, April 26, 2023 8:26:23 AM
Attachments: image001.png
7030-102137-000.pdf
23-0043
Good morning Alice,
Please see the attached interpretation request.
Let me know if you need anything.
Regards,
-Breanna
From: Allen Peterson <allen.peterson@qnergy.com>
Sent: Friday, April 14, 2023 3:31 PM
To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>
Cc: Steve Maughan <steve.maughan@qnergy.com>; Ory Zik <ory.zik@qnergy.com>
Subject: Qnergy PowerGen - Interpretation Request
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.
Attention: PHMSA's Office of Hazardous Materials, Information Center
Regarding: Qnergy PowerGen products and compliance with regulation.
Reference: Qnergy document 7030-102137-000 Rev A ( 20230414 )
Qnergy requests confirmation that the attached letter represents proper interpretation of
regulations.
The attached describes Qnergy’s PowerGen as battery-powered equipment, containing non-bulk
quantities of hazardous material which are necessary for equipment operation. Please confirm that
PowerGen products are excepted from regulation according to the specific exceptions identified.
Thank you for confirming this interpretation. Please look at the Qnergy website for any additional
product information and for details about PowerGen if needed.
Qnergy Engineering.
Allen Peterson

<<<PAGE 4>>>

Product Applications
Mechanical Engineer
Mobile: +1 801.833.4531
Email: Allen.Peterson@Qnergy.com
Website: qnergy.com
Address: 300 W 12th St., Ogden, UT 84404
This email or attachments includes Confidential Information, proprietary information, and sensitive information that must be
protected against unauthorized disclosure. If you have received this email in error, do NOT copy or retain the documents. Please
immediately destroy them and promptly notify the sender.

<<<PAGE 5>>>

Ory Zik
300 W 12th St.
Ogden, UT 84404
www.qnergy.com
(617) 943-3215
Ory.Zik@Qnergy.com
Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration
U.S. Department of Transportation, East Building
1200 New Jersey Avenue, SE.
Washington, DC 20590-0001
(800)467-4922
infocntr@dot.gov
ATTN: PHH-10,
Regarding: Interpretation of Federal Regulations, Title 49/Subtitle B/Chapter I and its subparts (‘the Code’).
According to the Code, section 105.20 and its parts, regarding compliance with, and interpretation of
regulations:
Qnergy requests review and approval of its interpretation of the Code, as applied to the following
commercial products.
Qnergy Inc. offers products for commerce and for international, interstate, and intrastate transportation. These
products include standalone, ‘battery-powered,’ stationary electrical equipment. Such Qnergy machinery
provides electricity at remote jobsites when gaseous fuel is supplied by customers to enable electrical power
generation. Qnergy equipment does not self-contain fuel and is completely purged of all fuel during transport.
Qnergy identifies products of this type within its ‘PowerGen’ model group, and possibly other future naming.
Qnergy generator equipment is excepted from the Code according to the following interpretation logic:
Identification of Hazardous Material
PowerGen standalone generators necessarily include an upright, non-spillable, wet battery. PowerGen batteries
are securely installed within the equipment’s strong outer enclosure, in conformance with the Code, section
173.159(a). Within the Code, Table 172.101, a PowerGen battery is identified as:
• UN2800, Division 8, Packaging group III, hazardous material
• PowerGen typically uses one battery, massing approximately <30kg TOTAL, which is non-bulk
transportation.
PowerGen consumes gaseous fuel to generate useful electricity for its users. To operate, PowerGen requires a
first combustion subfunction, which releases heat from customer-supplied onsite fuel sources. A second
required subfunction is power conversion. A proprietary, heat-pumping converter directly cools the combustion
equipment. Absorbed heat is processed within the converter by means of a closed, reversible thermodynamic
power cycle, creating pressure work, and then directly driving motion of an electrical alternator to generate AC-
electrical power available to users. The cooler/converter is directly heated by the combustor and can therefore
be referred to as an externally heated converter (EHC). Qnergy tradename for the EHC is presently QB80 but
Qnergy might choose different, alternative model naming over time.
7030-102137-000rA RELEASED 1

<<<PAGE 6>>>

The Code, Table 172.101, directs to Exception 173.307(a)(4)(i), applicable to either type of Division 2.2 heat
PowerGen’s EHC contains a hermetically sealed mass of heat transport media to enable cooling of the
combustor and then also conversion between heat transfer, pressure work, motion, and electricity. Within the
Code, Table 172.101, the specific EHC cooling media is identified as:
• UN1046, Division 2.2, compressed gas.
o This is helium. It is inert, non-flammable, non-oxidizing, non-poisonous, non-liquefied, non-toxic,
and not a hazard once decompressed.
• EHC cooling media will typically mass approximately <0.5kg, which is non-bulk transportation.
• Qnergy may use UN1066, Division 2.2 compressed gas as an alternative media in future EHC’s.
Exceptions:
transfer media transported within PowerGen. PowerGen is excepted from all of Chapter C requirements, since
the EHC and its media act together as a ‘refrigerating machine.’ A fixed pre-charge of compressed gas enables
the EHC to cool the PowerGen combustion function.
The term ‘refrigerating machines’ is not explicitly defined within the Code. Qnergy interprets the wording as:
• Refrigerating machines are equipment which remove heat from some other source (the combustor).
o Sub-ambient cooling capability is not explicitly required for refrigerating machines but is a well-
known capability when using ‘reversible’ power cycle EHC equipment of this type. If the
combustion subfunction of PowerGen is disabled, and the PowerGen EHC subfunction remains
operational, then the EHC heat exchanger temperature drops below ambient. Frost forms on
the heat absorber by freezing relative humidity out of local ambient air.
Both the EHC heat transfer media, and the non-spillable wet battery are integral to PowerGen and are necessary
for operation of the off-grid generator, once deployed, and commissioned at a remote jobsite. According to the
Code, Subchapter C, Exception 173.220(f)(1), both hazardous materials identified in this letter are excepted
from all of Subchapter C requirements, since they are both integral components that are necessary for
operation of the mechanical equipment.
PowerGen contains relatively small, non-bulk amounts of hazardous material within its strong outer enclosure
but is excepted from ALL of Subchapter C commercial transportation requirements within the Code.
Please verify approval of Qnergy’s interpretation of the Code or let us know if you have any questions.
Thankyou.
SIGN DATE
_____<on file>___ _2023, April 5_
Ory Zik Steve Maughan TBD Lawyer Signature Norman Newhouse _____<on file>___ _2023, April 5_
_____<on file>___ _2023, April 5_
_____<on file>___ _2023, April 5_
7030-102137-000rA RELEASED 2

<<<PAGE 7>>>

PowerGen Background Information – More information on PowerGen is available from the Qnergy website.
https://qnergy.com/powergen-series/
7030-102137-000rA RELEASED 3

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/77831/230043.pdf>
- Source ID: `phmsa`
- SHA-256: `5e7cf286c88d29654adb72e28b4441e21dc5ccb74b9c733e76d599b387b75512`
- Retrieved: 2026-08-20T00:59:31.977Z
- Exported: 2026-08-23T16:34:33.220Z
- Document slug: `phmsa-interpretation-23-0043`

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