# National Institute of Standards and Technology — Hazardous Materials Safety Interpretation

**Citation:** 07-0079  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2007-06-12

07-0079 response to National Institute of Standards and Technology concerning 172.402, 173.4.

## Document text

<<<PAGE 1>>>

of Transportation
U.S. Department
1200 New Jersey Ave.. S.E
Washington. DC 20590
Pipeline and Hazardous
Administration
Materials Safety
JUN 12 2007
National Institute of Standards and Technology
Mr. Larry Lucas
Ref. No.: 07-0079
100 Bureau Drive
Stop 8462
Gaithersburg, MD 20899-8462
Dear Mr. Lucas:
This is in response to your April 20, 2007 letter regarding subsidiary labeling requirements
under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically,
you ask it a subsidiary hazard label is required for a package the meets the definition of a
Class 7 (Radioactive) material and also meets the definition of a Class 8 (Corrosive) material.
The material in question is a solution of radioactive isotopes requiring a Class 7 hazard label
(typically Yellow-II), and 5 milliliters (<1/5 ounce) of a Class 8 acid.
Section 172.402(d) requires each package containing a Class 7 (Radioactive) material that
also meets the definition of one or more additional hazard classes to be labeled as a Class 7
(Radioactive) material, as required by § 172.403, and for each additional hazard. However,
the material satisfies the requirements of § 173.4 (small quantity exception).
an exception from the subsidiary labeling requirement is provided in § 172.402(d)(1) when
contact this office.
I hope this information is helpful. If you have further questions, please do not hesitate to
Sincerely.
John A Gate i"
Chief, Standards Development
Office of Hazardous Materials Standards
172.402 (d)
173.4
070079

<<<PAGE 2>>>

INFOCNTR <PHMSA>
From:
Sent:
Larry Lucas [larry.lucas@nist.gov]
To:
Friday, April 20, 2007 6:00 PM
Eichenlaub
Subject:
Cc:
INFOCNTR <PHMSA>
Janna Shupe; Corey Hankerson; Roy Parker
3172.101
Request for Written Letter of Interpretation
$173.4
20 April 2007
Labeling/Small Quantity Erceptio,
Request for Written Letter of Interpretation
07-0079
i talked with Chris on the HMR hotline yesterday and we both agreed that it would be i
importance of this issue to many other people.
jood idea for me to request a formal Written Letter of Interpretation because of thi
The situation is as follows:
than 10 years.
shipped as Radioactive Material, Excepted Package - Limited Quantity of Material, UN2910
(henceforth referred to as RMEP).
The majority of our radioactivity SRMs are solutions, with the radioactive material
dissolved in (typically) 5 milliliters
ounce) of aqueous solution that also contains non-radioactive carrier and some acid
that it is acceptable aboard passenger
(typically hydrochloric or nitric).
The final concentration of the acid is always such
sealed glass ampoule surrounded by
containment within a protective cardboard tube.
absorbent material and several layers of secondary
The solution is contained in a flame-
cushioning material and contained in a UN4G fibreboard box as the outer container.
The cardboard tube is surrounded by
packages meet the Type-A performance specifications, regardless of the final labeling.
Al1
hazard and one label (either the IATA DGEQ label or the DOT 173.4 conformance statement)
Most of the packages are shipped with two labels: one RMEP label for the radioactivity
for the corrosive hazard. These package have never been an issue.
My question is about the packages we
lived medical isotope contained or because of the dose rate) must be labeled with a Class
ship that (either because of the quantity of short-
7 hazard label (typically II-Yellow).
5 milliliters (<1/5 ounce) of acid solution.
The question is about the proper declaration of the
require that once a package must be labeled with a hazard label for any Class, then all
It seems that the present regulations
other hazard classes must also have Class labels (and be declared as subsidiary risks)
without regard to the quantity of material in that Class (even one drop).
example above, the II-Yellow label must be accompanied by
• a Class 8 Corrosive label and
Thus, in the
the acid solution must be declared as a subsidiary risk (8).
are any other options.
Thank you and best regards,
Larry Lucas, Research Chemist
MD 20899-8462
National Institute of Standards and Technology 100 Bureau Drive, Stop 8462 Gaithersburg,
Telephone: 1-301-975-5546
Facsimile: 1-301-926-7416
Email: larry.lucas@nist.gov
1

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2007/070079.pdf>
- Source ID: `phmsa`
- SHA-256: `b1d84185bfc369d3eca23478d3cf3737283e5647a9057d282a527c1c134f55ff`
- Retrieved: 2026-08-20T00:59:31.977Z
- Exported: 2026-08-22T21:14:14.855Z
- Document slug: `phmsa-interpretation-07-0079`

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