# ISOTECH Laboratories, Inc. — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 06-0283
- **title:** ISOTECH Laboratories, Inc. — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2007-04-03
- **effective on:** Not available
- **summary:** 06-0283 response to ISOTECH Laboratories, Inc. concerning 173.11, 173.116, 173.133, 173.22.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-06-0283.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-06-0283.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-06-0283
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2006/060283.pdf
**body:**

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U.S. Department
of Transportation
Washington, D.C. 20590
400 Seventh Street, S.W.
Pipeline and
Administration
Hazardous Materials Safet
APR 3
2007
Mr. Dennis Coleman
ISOTECH Laboratories, Inc.
President
Ref. No. 06-0283
Champaign, IL 61821-1826
1308 Parkland Court
Dear Mr. Coleman:
mixture of natural gas containing a hydrogen sulfide (HS) concentration level not
This responds to your letter dated December 21, 2006 regarding whether a sample
exceeding 14% (on a molar basis) may be transported by all modes of transportation
without labeling the sample toxic inhalation hazard.
Isotech Laboratories, Inc. (Isotech) analyzes natural gas samples for commercial
containing small amounts of HS. Based on your review of the Class 2 assignment of
consumers located in the United States and abroad. Samples are shipped to Isotech
hazard zones in §173.116(a) and your calculations according to §173.133(b)(1), you
determined that the concentration level of HS in a mixture of natural gas could reach
14% (on a molar basis) before being considered toxic-by-inhalation and requiring a 2.3
(Poison Gas) label. Specifically, you ask whether your calculated concentration level is
H›S concentration not exceeding 14% (on a molar basis) classed as Division 2.1
correct; thus, allowing Isotech and its customers to ship natural gas samples containing an
(Flammable Gas) and not Division 2.3 (Poison Gas), which is toxic-by-inhalation,
requiring display of a POISON GAS label.
Under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180), it is a
shippers responsibility to classify a hazardous material (See §173.22). This Office does
provided, it is our opinion that a sample mixture of natural gas containing a hydrogen
sulfide (H,S) concentration level not exceeding 14% (on a molar basis) may be
173.11 (a)
173.22
173.116
060283
173133(6)(1)

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transported by all modes of transportation as a Division 2.1 (Flammable Gas) material
without labeling the sample toxic inhalation hazard.
I hope this satisfies your inquiry. If we can be of further assistance, please contact us.
Sincerely,
Pantone f
Chief, Standards Development
Office of Hazardous Materials Standards

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Engrum
$172.701
AlISOTECH
$ 173.115
§173.114
www.isotechlabs.com
mail@isotechlabs.com
Isotech Laboratories, Inc. 1308 Parkland Court Champaign, IL 61821-1826
Telephone 217/398-3490 FAX 217/398-3493
December 21, 2006
Applicability
06-0283
Via UPS Next Day Air
Office of Hazardous Material Standards
Attn: PHH-10
Pipeline and Hazardous Materials Safety Administration
400 7th Street, S.W.
U.S. Department of Transportation
Washington, D.C. 20590-001
Re:
Permissible Non-toxic Hydrogen Sulfide Concentrations
Dear Sir or Madam:
consumers located in the United States and abroad.! Isotech seeks PHMSA's confirmation that
Isotech Laboratories, Inc. ('Isotech") analyzes natural gas samples for commercial
a sample mixture of natural gas containing a hydrogen sulfide ("H¿S") concentration level not
exceeding 14% (on a molar basis) may be transported on all modes of transportation without
labeling the sample as a toxic inhalation hazard.
reviewed the HAZMAT regulations and noted that HS, in its pure form and at specific
On occasion, samples are shipped to Isotech containing small amounts of HaS. We
require 2.3 labeling as a toxic inhalation hazard.? We then set out to determine what
concentration levels, is considered a division 2.3 gas poisonous by inhalation and thus would
concentration of HS would be permissible for transport, without 2.3 labeling, under all modes
of transportation, assuming the quantity limitations of 49 CFR $172.101 columns 9(A), 9(B), and
10 were met. Based on our review of the Class 2 assignment of hazard zones (§173.116(a)) and
our calculations per 49 CFR §173.133(b)(1), we determined that the concentration level of H_S in
mixture of natural gas could reach 14% (on a molar basis) before being considered toxic an
herefore, requiring class 2.3 labeling. Although we have received tentative verbal confirmatio
from a PHMSA chemist that our calculated concentration level is correct, out of an abundance
of caution we seek PHMSA's written confirmation that:
Isotech and its customers may ship natural gas samples containing an H2S
concentration not exceeding 14% (on a molar basis) as Flammable Gas,
1 See www.isotechlabs.com.
2 See 49 CFR S§173.115, 172.416.

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Office of Hazardous Material Standards
December 21, 2006
Page 2
sample as a toxic inhalation hazard.
Class 2.1, on all allowable modes of transportation without labeling the
you have any questions or require additional information, please do not hesitate to contact me
We thank you in advance for providing us with the above-requested confirmation. If
at the above-listed number.
Very truly yours,
die meltilina.
President
Dennis D. Coleman
İsotech Laboratories, Inc. 1308 Parkland Court Champaign, IL 61821-1826
Telephone 217/398-3490 FAX 217/398-3493
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