# Matson Navigation Company — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 22-0021
- **title:** Matson Navigation Company — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2023-01-24
- **effective on:** Not available
- **summary:** 22-0021 response to Matson Navigation Company concerning 176.907.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-22-0021.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-22-0021.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-22-0021
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/77206/220021.pdf
**body:**

<<<PAGE 1>>>

U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
January 24, 2023
Mr. James Owen
Dangerous Goods Specialist
Safety, Quality, Environment, and Security
Matson Navigation Company
426 North 44th Street, Suite 250
Phoenix, AZ 85008
Reference Nos. 22-0021 & 22-0061
Dear Mr. Owen:
This letter is in response to your March 25, 2022, and June 8, 2022, correspondence requesting
clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable
to polymeric beads transported in cargo transport units in accordance with § 176.907.
We have paraphrased and answered your questions as follows:
Q1. You ask whether your understanding is correct that an explosion-proof refrigerated cargo
transport unit is not required when transporting polymeric beads, provided the
requirements pertaining to cargo transport units in § 176.907(b) are met.
A1. Your understanding is correct. The requirement that a cargo transport unit be “explosion-
proof” is required under § 176.907(a) for any mechanical devices used for ventilation and
does not apply to refrigerating equipment used to comply with the alternative provisions
in § 176.907(b).1
Q2. In your correspondence, you reference the requirement in § 176.907(d) for the marking
and stowage of polymeric beads. You ask whether a refrigerated cargo transport unit
used to satisfy the requirements in § 176.907(b) must be “powered off” prior to unloading
to be clear of any source of ignition as specified in § 176.907(d)(2).
1 Please note that polymeric beads will release volatile hydrocarbons during storage and transportation. The rate of release increases with
temperature. In enclosed spaces and under warmer temperatures during normal conditions of transportation, polymeric beads may release a
flammable concentration of gas, necessitating the safety controls in paragraph (a) to ensure proper ventilation and to prevent mechanical devices,
such as an electric fan, from being a source of ignition. Refrigerated cargo transport units, however, are not subject to the ventilation or
explosion-proof requirements for mechanical devices as the cooler temperatures provided by the refrigeration unit suppress the release of volatile
hydrocarbons.

<<<PAGE 2>>>

A2. If—as a result of being powered on—the refrigerated cargo transport unit is a source of
ignition, then it must be powered off prior to performing loading and unloading
operations. The refrigerated cargo transport unit should be powered on as soon as
practicable once loading operations are complete.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

<<<PAGE 3>>>

Matson.
Pollack
Navigation Company Inc.
22-0021
Friday, March 25, 2022
Standards and Rulemaking PHH-10
Pipeline and Hazardous Materials Safety Administration
U.S. Department of Transportation
1200 New Jersey Avenue, SE
Washington, DC 20590
United States
RE:§ 49CFR176.907 Polymeric Beads and Plastic Molding Compounds.
To Whom It May Concern:
I am writing to request a letter of interpretation for the shipping of polymeric beads in refrigerated
containers. Specifically I am looking for clarifying in writing regarding the use of regular refrigerated
cargo transport unit vs that of explosion proof CTU's.
Section (a) below notes the need for explosion proof devises if they are mechanical when transporting
polymeric beads in a cargo transport unit. Section (b) does not note this and appears to be an
alternative to (a) thus is it my understanding that under section (b) an explosion proof refrigerated cargo
transport unit is not required and a regular reefer would meet the requirements of this subchapter,
provided the packages meet the packaging requirements for the product.
§ 49CFR176.907 Polymeric Beads and Plastic Molding Compounds.
(a) When transported in cargo transport units, the cargo transport units must provide an
adequate exchange of air in the unit. This adequate exchange of air may be accomplished by
utilizing a ventilated container, an open-top container, or a container in one door off
operation. When cargo transport units with venting devices are used these devices should be
kept clear and operable. If mechanical devices are used for ventilation, they must be
explosion-proof.
(b) As an alternative to the options presented in paragraph (a) of this section to ensure an
adequate exchange of air; a refrigerated cargo transport unit may be used.

<<<PAGE 4>>>

It would also be my understanding based on (d)(2) that the reefer should be powered off prior
to unloading to negate any potential source of ignition. Please confirm.
(d) Cargo transport units must be marked with a warning mark including the words "CAUTION
- MAY CONTAIN FLAMMABLE VAPOR" or "CAUTION - MAY CONTAIN FLAMMABLE VAPOUR"
with lettering having a height of at least 25 mm (1 inch). The mark must be affixed to each
access point in a location where it will be easily seen by persons prior to opening or entering
the cargo transport unit and must remain on the cargo transport unit until the following
provisions are met:
(1) The cargo transport unit has been completely ventilated to remove any hazardous
concentrations of vapor or gas;
(2) The immediate vicinity of the cargo transport unit is clear of any source of ignition; and
(3) The hazardous materials have been unloaded.
James Owen
Dangerous Goods Specialist
Safety, Quality, Environment, and Security
Matson Navigation Company
426 N 44t St, Ste 250
Phoenix, AZ 85008
Office 480-902-5015
Cell 480-653-1114
jowen@matson.com
www.matson.com

<<<PAGE 5>>>

Cardez
Matson®
22-0061
Navigation Company Inc.
Wednesday, June 8, 2022
Associate Administrator for Hazardous Materials Safety
PHMSA
U.S. Department of Transportation
Attention: PHH-30
1200 New Jersey Avenue, SE East Building, 2nd Floor
Washington, DC 20590-0001
RE:
§ 176.907 Polymeric Beads and Plastic Molding Compounds.
To Whom It May Concern:
I am requesting a letter of interpretation regarding the stowage of polymeric beads. Specifically 1 am asking for
clarification regarding the use of refrigerated cargo transport units. Based on the below excerpt it is my
understanding that a standard refrigerated cargo transport unit is acceptable for use when transporting polymeric
beads to ensure proper ventilation. It is not my belief that an explosion proof refrigerated cargo transport unit is
required as they are with class 2.1's. Please confirm via LOI.
(a) When transported in cargo transport units, the cargo transport units must provide an adequate exchange of
air in the unit. This adequate exchange of air may be accomplished by utilizing a ventilated container, an open-
top container, or a container in one door off operation. When cargo transport units with venting devices are
used these devices should be kept clear and operable. If mechanical devices are used for ventilation, they must
be explosion-proof.
(b) As an alternative to the options presented in paragraph (a) of this section to ensure an adequate exchange of
air; a refrigerated cargo transport unit may be used.
10-
James Owen
Dangerous Goods Specialist
Safety, Quality, Environment, and Security
Matson Navigation Company
426 N 44'h St, Ste 250
Phoenix, AZ 85008
Office 480-902-5015
Cell 480-653-1114
jowen@matson.com
www.matson.com
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