# URS Corporation — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 04-0249
- **title:** URS Corporation — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2005-02-10
- **effective on:** Not available
- **summary:** 04-0249 response to URS Corporation concerning 173.220.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-04-0249.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-04-0249.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-04-0249
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2004/040249.pdf
**body:**

<<<PAGE 1>>>

U.S. Department
of Transportation
400 Seventh St., S.W.
Washington, D.C. 20590
special Programs
Research and
Administration
FEB 1Q 2005
Mr. Andrew N. Romach
Ref No.: 04-0249
Corporate Regulatory Manager
URS Corporation
1600 Perimeter Park Drive
Morrisville, NC 27560
Dear Mr. Romach:
This responds to your October 27, 2004 letter requesting clarification of the Hazardous
Materials Regulations (HMR; 49 CFR Parts 171-180) as applicable to jet engines.
Specifically, you ask if jet engines may be classed as "Engines, internal combustion." In
component referred to as a "spark gap." You indicate that the "spark gap" contains a
addition, you state that the exciter box, an integral component of jet engines, contains a
limited quantity of Krypton-85 gas, a radioactive material assigned to UN2910. You ask if
a cleaned and purged jet engine and securely installed "spark gap" may be shipped as
unregulated material in accordance with § 173.220(a)(1) and (d)(1), respectively.
Aircraft engines, whether piston-powered, rotary-powered, or turbine-powered, derive their
power by heat and pressure produced by the compression and combustion of a fuel-air
mixture. Therefore, aircraft engines including jet engines are properly classified as
"Engines, internal combustion, 9, UN3166."
In accordance with § 173.220(a)(1), an engine that is completely drained, sufficiently
cleaned of residue, and purged of vapors to remove any potential hazard and that will not
release liquid fuel in any orientation is not subject to the HMR. In addition, a limited
quantity of radioactive material that is contained in a securely installed engine component
that is integral to the operation of the engine is excepted from the requirements of the HMR
(see § 173.220(d)(1)). Therefore, a cleaned and purged jet engine with a "spark gap"
contained in a securely installed exciter box is excepted from the requirements of the HMR,
provided the applicable requirements in § 173.220 are met.
I hope this information is helpful. Please contact us if you require additional assistance.
Sincerely,
Edward T. Mazzullo
Director
Office of Hazardous Materials Standards
173.220
040249

<<<PAGE 2>>>

Supko
URS
$173.220
October 27, 2004
Engines
04-0249
Mr. Ben Supko
Office of Hazardous Material Standards
Research and Special Programs Administration
U.S. Department of Transportation
400 7th Street, SW (DHM-10)
Washington, DC 20590-0001
FAX: (202) 366-3012
Dear Mr. Supko:
Q-1 I am writing to you to request a written regulatory interpretation concerning whether
an Jet engine would be considered an Internal Combustion Engine for the purposes of
hazard classification and shipment under the DOT HAZMAT regulations.
In the Hazardous Material Table (49 CFR 172.101), for the proper shipping name
Engines, Internal Combustion, column (d) references 49 CFR 173.220. Paragraph (d)(1)
integral components of the engine and necessary for the operation of the engine to be
of 49 CFR 173:220 allows items of equipment containing hazardous materials, which are
shipped as not subject to the DOT HAZMAT regulations, so long as these items are
securely installed in the engine.
Aircraft jet engines contain a spark gap. The spark gap, which separately is shipped as a
item of equipment that is an integral component of any aircraft engine and necessary for
radioactive material excepted package due to a very low amount of Krypton-85 gas, is an
the operation of the engine. The spark gap is securely affixed inside an exciter box,
which is securely installed in the engine.
Q-2 Would we be able to ship a jet engine with a spark gap securely installed as DOT not
restricted if the aircraft engine is cleaned and purged of all residual fuel and meets the
requirements of 49 CFR. 173.220(a)(1): "An engine may be considered as not containing
Tue! when the fuel tank, engine components, and fuel lines have been completely drained,
sufficiently cleaned of residue, and purged of vapors to remove any potential hazard and
the engine when held in any orientation will not release any liquid fuel."
Thank you for your consideration of this request.
Sincerely,
Alize
Andrew N. Romach
Corporate Regulatory Manager
URS Corporation
JRS Corporatior
Morrisville, NC 27560
600 Perimeter Park Drive
Tel: 919.461.1220
Fax:919.461.1371
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