# Ms. Sandra Harding — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 12-0235
- **title:** Ms. Sandra Harding — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2013-02-08
- **effective on:** Not available
- **summary:** 12-0235 concerning 175.700, 175.75.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-12-0235.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-12-0235.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-12-0235
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2013/120235.pdf
**body:**

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U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
1200 New Jersey Avenue, SE
Washington, D.C. 20590
FEB 0 8 2013
Ms. Sandra Harding
3 7 41 Eight Mile Road
Melbourne, KY 41059
Reference No.: 12-0235
Dear Ms. Harding:
This is in response to your October 19, 2012 email to the Hazardous Materials Information
Center requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts
171-180) applicable to aircraft quantity limitations and cargo location.
You observe that Variation US 13 in the International Civil Aviation Organization Technical
Instructions for the Safe Transport of Dangerous Goods by Air (ICAO TI) is not consistent
with the current language ofthe HMR. You provide an outline of your understanding of the
current requirements ofHMR § 175.75(b) through (f) relating to accessibility requirements
and quantity limitations and ask if your understanding is correct.
Your understanding of the current requirements ofHMR § 175.75, pertaining to the loading
and transport of hazardous materials aboard an aircraft and Variation US 13 of the ICAO TI,
as you outlined in your email are correct.
You are also correct that Variation US 13 in the ICAO TI is not consistent with the current
language ofHMR § 175.75. However, Variation US 13 does indicate that operators must
comply with all requirements of Part 175 of the HMR. The revision of Variation US 13 is
under consideration for an international harmonization initiative.
You also ask PHMSA's reasoning for not excluding Class 7 materials from the quantity
limitations on passenger aircraft.
Class 7 materials were inadvertently not excluded from the quantity limitations for
passenger aircraft in HMR § 175.75(c). The limitations for the transport of Class 7 materials
by aircraft are provided in HMR § 175.700. The revision ofHMR § 175.75(c), to exclude
Class 7 materials, may be considered for a future rulemaking.
ust this satisfies your inquiry. Please contact us ifwe can be of further assistance.
cerely, ~
~ ~
DelmerB~~
Senior Regulatory Advisor
Standards and Rulemaking Division

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Drakeford, Carolyn (PHMSA)
From:
Sent:
To:
Subject:
INFOCNTR (PHMSA)
Monday, October 22, 2012 11:35 AM
Drakeford, Carolyn (PHMSA)
FW: Request for clarification 49 CFR 175.75
I 1 -()JL;35
Hi Carolyn,
Thanks,
Victoria
We received the following request for a formal letter of interpretation.
From: Sandra Harding [mailto:sharding29@gmail.com]
Sent: Friday, October 19, 2012 1:15 PM
To: INFOCNTR (PHMSA)
Subject: Fw: Request for clarification 49 CFR 175.75
CORRECTION TO "ADDITIONAL QUESTION" below:
From: Sandra Harding
Sent: Friday, October 19, 2012 1:08PM
To: infocntr@dot.gov
Subject: Request for clarification 49 CFR 175.75
Dear PHMSA,
I am writing to request clarification of the operator requirements for loading hazardous materials as described
in 49 CFR 175.75.
I am not yet in possession of the 2013-20141CAO Technical Instructions to be able to verify whether ICAO Tl
Variation US-13 has been amended to correspond with the current 175.75, but I do have the 20131ATA DGR
which still contains what I believe is outdated information in USG-13 (d).
Can you please advise whether my understanding of 49 CFR 175.75 (b) through (f) as outlined below is correct:
A. ACCESSIBILITY REQUIREMENTS
Packages/overpacks labeled "CARGO AIRCRAFT ONLY" must be loaded on a cargo-only aircraft where they can
be (definition of uaccessibility") accessed, handled and where size and weight permit, relocated away from
other cargo inflight, OR loaded in a Class C cargo compartment (OR in a ULD approved as meeting Class C
requirements).
These requirements to NOT apply to CAO packages/overpacks of the following:
Class 3, PG Ill, except those having a Class 8 subsidiary risk;
Division 6.1, PG II and Ill only, except those having a Class 3 subsidiary risk;
Division 6.2,
Class 7, provided they do not have a subsidiary risk;
Class 9
1

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B. LOAD QUANTITY LIMITATIONS:
On PASSENGER AIRCRAFT:
No more than 25 kg net weight of dangerous goods, and an additional 75 kg of 2.2 gas, may be loaded in an
inaccessible cargo compartment.
The following are not subject to the above limitations:
Class 9;
Packages prepared in accordance with the limited Quantity provisions of ICAO Tl;
Packages prepared in accordance with the Excepted Quantity provisions of ICAO Tl.
ON CARGO·ONL Y AIRCRAFT:
Packages/overpacks labeled "CARGO AIRCRAFT ONLY" must meet accessibility requirements as above.
For packages/overpacks NOT labeled "CARGO AIRCRAFT ONLY", the following limitations apply:
No more than 25 kg net weight of hazardous materials, and and additional 75 kg net weight of 2.2 gas, may be
loaded in an inaccessible manner on the aircraft.
Class C cargo compartment are considered to be "accessible" for the purposes of this section, e.g., there are no
loading quantity restrictions for hazardous materials loaded in Class C compartments of a cargo-only aircraft.
The following are not subject to the above limitations:
Class 3, PG Ill, except those having a Class 8 subsidiary risk;
Division 6.1, PG II and Ill only, except those having a Class 3 subsidiary risk;
Division 6.2;
Class 7, provided they do not have a subsidiary risk;
Class 9;
Packages prepared according to the Limited Quantity or Excepted Quantity provisions of the ICAO Tl.
ADDITIONAL QUESTION:
Regarding the loading quantity limits above, was it your intention to NOT exclude Class 7 from the quantity
restrictions on passenger aircraft, being that:
A. Radiation hazard is typically established based on radiation emitted rather than net quantity transported;
B. Required declaration documentation for Class 7 indicates Category/Transport Index rather than net quantity.
YOUR ASSISTANCE IS GREATLY APPRECIATED!!!!!
Sandra Harding
sharding29@gmail.com
TEL: 859.441.4385
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