# Deitrich Engineering — Hazardous Materials Safety Interpretation

**Citation:** 14-0153  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2014-11-28

14-0153 response to Deitrich Engineering concerning 171.7, 173.22.

## Document text

<<<PAGE 1>>>

of Transportation
U.S. Department
1200 New Jersey Avenue SE
Washington DC 20590
Safety Administration
Pipeline and Hazardous Materials
NOV 2 8 2014
Mr. David Dietrich
Dietrich Engineering
P.O. Box 7
Cool, CA 95614
Ref. No.: 14-0153
Dear Mr. Dietrich:
This responds to your July 28, 2014 letter requesting clarification of the Hazardous Materials
Regulations (HMR; 49 CFR Parts 171-180) applicable to a self-heating material classified as a
Division 4.2 spontaneously combustible material. In your letter, you state that you have a client,
Gesellschaft fuer Gefahrgut m.b.H., in Romanshorn, Switzerland, that is arranging import of a
pharmaceutical comprised of an iron-based phosphate binder for kidney disease patients. You
further state that this material has been classified as "UN3088, Self-heating solid, organic, n.o.s, 4.2,
PG II." Finally, you reference 5.2.2 of Appendix 6 (Screening Procedures) of the United Nations
(UN) Manual of Tests and Criteria which specifies that for Substances which may be liable to
spontaneous combustion (Division 4.2):
The classification procedure for self-heating substances need not be applied if the results of a
screening test can be adequately correlated with the classification test and an appropriate safety
margin is applied. Examples of screening tests are:
a) The Grewer Oven test (VDI guideline 2263, part 1, 1990, Test methods for the
Determination of the Safety Characteristics of Dusts) with an onset temperature 80 K
above the reference temperature for a volume of 1 1(33.3.1.6);
b) The Bulk Powder Screening Test (Gibson, N. Harper, D.J. Rogers, R. Evaluation of the
fire and explosion risk in drying powders, Plant Operations Progress, 4 (3), 181-189,
1985) with an onset temperature 60 K above the reference temperature for a volume of 1
1(33.3.1.6).
Your questions are paraphrased and answered below.
Q1: You ask whether Appendix 6 is permitted to be used under the HMR?
Al:
The answer is yes. As provided in § 171.7(dd) of the HMR, the "UN Recommendations on
the Transport of Dangerous Goods, Model Regulations (UN Recommendations), 17th
revised edition, Volumes I and II (2011)," and the "UN Recommendations on the Transport
revised edition, amendment 1 (2011)" are matters incorporated by reference in the HMR.
of Dangerous Goods, Manual of Tests and Criteria (UN Manual of Tests and Criteria), Fifth
Therefore, Appendix 6 to the UN Manual of Tests and Criteria is appropriate for use under
the HMR.

<<<PAGE 2>>>

Q2: You ask whether Screening Procedure 5.2.2 of Appendix 6 can be considered an alternative
"classification method"?
A2: The answer is yes, but with the following caveats. As required by § 173.22 of the HMR, it is
the shipper's responsibility to properly class a hazardous material. This Office generally
does not perform this function. Appendix 6 to the UN Manual of Tests and Criteria provides
the screening procedures industry uses to identify the hazard potential of raw materials,
reactive mixtures and intermediates, products, and by-products. The use of such procedures
is essential to ensure safety during research and development and to ensure that new products
and processes are as safe as possible. These procedures usually consist of a combination of a
theoretical appraisal and small-scale tests, and in many cases, enable an adequate hazard
evaluation to be carried out without the need for larger scale classification tests. This
reduces the quantity of material required, lessens any detrimental effect on the environment,
and minimizes the amount of unnecessary testing.
The purpose of Appendix 6 to the UN Manual of Tests and Criteria is to present examples of
screening procedures. It should be used in conjunction with any screening procedures given
in the introductions to the relevant test series. With the specified safety margin, the results
from the screening procedures adequately predict when it is not necessary to perform the
classification test as a negative result would be obtained. They are presented for guidance
and their use is not compulsory. Other screening procedures may be used provided that
adequate correlation has been obtained with the classification tests on a representative range
of substances and there is a suitable safety margin.
If you perform the Grewer Oven test or the Bulk Powder Screening test as provided in 5.2.2
of Appendix 6 of the UN Manual of Tests and Criteria and the results of those screening tests
can be adequately correlated with the classification test and an appropriate safety margin,
then the classification procedure for self-heating substances need not be applied. However,
depending on the results of those tests, a packing group could still need to be determined or
the material you are classifying may meet the definition of another hazard class altogether.
Q3: You ask whether a Special Permit is required?
A3:
The answer is no.
I trust this satisfies your inquiry. Please contact us if we can be of further assistance.
Sincerely,
ten oste
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
2

<<<PAGE 3>>>

Nickels
173.125
P.O.Box 7
Cool, CA 95614
28 July 2013
U.S. Dept. of Transportation
PHMSA East Bldg, 2nd Floor
1200 New Jersey Ave. SE
Washington, DC 20590
Attn: Office of Standards
Re: Inquiry Letter
to whom it may concern:
On 23 July 2014, I spoke to Mr. Matt Nichols about this matter. On 25 July I spoke
to Ms. Diane Lavalle about special permits. Both staff of PHMSA were
knowledegable and helpful. Because the technical questions are so complicated, i am
requesting a written clarification.
This inquiry involves a conflict between 49CFR and the UN classification of
dangerous goods. My client, Gesellschaft fuer Gefahrgut m.b.H., in Romanshorn,
Switzerland, seeks to arrange import of a pharmaceutical based on UN3088, a solid,
iron-based phosphate binder for kidney disease patients. My client's UN3088 is
Division 4.2, PG-I, according to the UN Manual of Tests as required in
49CFR173.125. That's the key, both 49CFR and UN regulations specify the same lab
test manual.
Appendix 6 of that same UN Manual allows an alternative method of classification
for Division 4.2 in that:
"5.2.2. The classification procedure for self-heating substances need not be
applied if the results of a screening test can be adequately correlated with the
classification test and an appropriate safety margin is applied. Examples of
screening tests are (...Grewer Oven Test and Bulk Powder Screening Test)."
That gets to my question. I do not find Appendix 6 mentioned in 49CFR. Is that
alternative classification method available in the PHMSA view? Is a special permit
required or it there a simpler way?
Thank you for your attention to this urgent matter.
Sincerely,
...!.::
f05**55
Datal
David Dietrich, PE
emai(
modesto3@gmail.com

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2014/140153.pdf>
- Source ID: `phmsa`
- SHA-256: `af1d8f1ffda0f2eb5d63ba546f1b3a67ed618d45c58e6a0f9a1848a3356b8a4a`
- Retrieved: 2026-08-20T00:59:31.977Z
- Exported: 2026-08-22T10:06:47.693Z
- Document slug: `phmsa-interpretation-14-0153`

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