[Federal Register Volume 82, Number 77 (Monday, April 24, 2017)]
[Notices]
[Pages 18967-18968]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-05614]
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DEPARTMENT OF TRANSPORTATION
Pipeline and Hazardous Materials Safety Administration
[Docket No. PHMSA-2016-0078; Notice No. 2016-14]
Hazardous Materials: Use of DOT Specification 39 Cylinders for
Liquefied Flammable Compressed Gas
AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA),
DOT.
ACTION: Safety advisory notice, revised.
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SUMMARY: PHMSA is issuing this revised safety advisory notice to
address concerns of offerors and users of DOT Specification 39 (DOT-39)
cylinders that exceed 75 cubic inches (in\3\) (1.23 L) and to provide
clarification of the initial safety advisory notice we issued on this
subject on December 13, 2016 (Notice No. 2016-14). DOT-39 cylinders
exceeding 75 in\3\ (1.23 L) should not contain liquefied flammable
compressed
[[Page 18968]]
cyclopropane, ethane, or ethylene, or liquefied petroleum gases. PHMSA
advises against the filling or transporting of these gases in DOT-39
cylinders when the cylinder's internal volume exceeds 75 in\3\ (1.23
L).
FOR FURTHER INFORMATION CONTACT: Refaat Shafkey, General Engineer,
Engineering and Research Division, Office of Hazardous Materials
Safety, Pipeline and Hazardous Materials Safety Administration, U.S.
Department of Transportation, 1200 New Jersey Avenue SE., Washington,
DC 20590. Telephone: (202) 366-4545 or email: [email protected].
SUPPLEMENTARY INFORMATION:
A. Public Action Requested
PHMSA advises that DOT-39 cylinders having an internal volume
exceeding 75 cubic inches (in\3\) (1.23 L) should not contain liquefied
flammable compressed cyclopropane, ethane, or ethylene, or liquefied
petroleum gases. These gases were historically restricted to this
volume for shipment in specification cylinders (currently Sec.
173.304a). This limitation was based on extensive experience under
special permits and the consideration that, in transportation and
without the limitation, non-reusable cylinders of larger sizes (and
lower integrity) would be used in place of authorized higher-integrity
reusable cylinders. Use of these DOT-39 non-reusable cylinders in
larger sizes would lower the level of transportation safety previously
established through use of higher-integrity reusable cylinders for the
shipment of flammable gases. See the Background section for additional
information on this issue.
B. Safety Concern
The release of a liquefied flammable compressed gas as result of
the failure of a cylinder having an internal volume exceeding 75 in\3\
(1.23 L) is a safety concern with potential to cause property damage,
serious personal injury, or even death. A DOT-39 cylinder, without
further size restriction, can have a volume of up to 1,526 in\3\ (25 L)
at a service pressure of 500 psig or less and, as such, can have up to
20 times the stored energy of a DOT-39 cylinder limited to 75 in\3\
(1.23 L). This increased stored energy presents a greater safety risk
in the event of a release. Additionally, because of the design
specifications that allow for thinner walls when used at lower
pressure, these cylinders may be at greater risk from corrosion or
puncture. Given the known risks associated with cylinders that are
filled with liquefied flammable compressed gases, PHMSA is issuing this
revised safety advisory notice to advise offerors and transporters of
DOT-39 cylinders that those with an internal volume greater than 75
in\3\ (1.23 L) should not be filled and/or transported with liquefied
compressed cyclopropane, ethane, or ethylene, or with liquefied
petroleum gases.
C. Background
This revised safety advisory notice is being issued in part because
of safety concerns stemming from a past rulemaking action impacting
DOT-39 cylinders used for certain liquefied flammable compressed gases.
In an October 30, 1998 notice of proposed rulemaking (NPRM),\1\ the
Research and Special Programs Administration (RSPA)--the predecessor
administration to PHMSA--proposed to extend the 75 in\3\ (1.23 L)
volume limitation of DOT-39 cylinders to all liquefied flammable
compressed gases by revising Sec. 173.304 to delete Note 9 from the
table at Sec. 173.304(a)(2) and adding new sections 173.304a and
173.304b.\2\ RSPA received several comments in opposition to this
proposal. RSPA published a final rule on August 8, 2002 and, based on
the opposing comments, decided not to extend the 75 in\3\ (1.23 L)
limitation to all liquefied flammable compressed gases in a DOT-39
cylinder at that time. However, in the process of publishing the final
rule, the administration inadvertently omitted the 75 in\3\ (1.23 L)
limitation from the Hazardous Materials Regulations (HMR; 49 CFR parts
171-180) for cyclopropane, ethane, ethylene, or liquefied petroleum
gas.\3\ Thus, historically, the HMR limited the internal volume of a
DOT-39 cylinder to 75 in\3\ (1.23 L) when used for these gases.
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\1\ NPRM--Hazardous Materials: Requirements for DOT
Specification Cylinders (HM-220D) [63 FR 58460].
\2\ The respective additional requirements for liquefied
compressed gases have since been redesignated at Sec. 173.304a).
\3\ Final Rule--Hazardous Materials: Requirements for
Maintenance, Requalification, Repair and Use of DOT Specification
Cylinders (HM-220D) [67 FR 51625].
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On November 13, 2014, PHMSA accepted a petition for rulemaking (P-
1622) from Worthington Cylinders to address this error. On July 26,
2016, PHMSA published in the Federal Register an NPRM titled,
``Hazardous Materials: Miscellaneous Amendments Pertaining to DOT
Specification Cylinders (RRR),'' [81 FR 48977; Docket No. PHMSA-2011-
0140 (HM-234)] \4\ that proposed to extend the limit on the internal
volume of DOT-39 cylinders to use with all liquefied flammable
compressed gases, thus correcting the inadvertent omission and seeking
comment regarding the possibility of expanding the applicability to
capture those liquefied flammable compressed gases (e.g.,
difluoromethane (Refrigerant gas R 32)) either not reflected in the
Sec. 173.304a(a)(2) table or not considered a liquefied petroleum gas.
Additionally, the NPRM further sought input on past experience with the
transport of liquefied flammable compressed gases in DOT-39 cylinders
larger than 75 in\3\ (1.23 L) since implementation of the 2002 final
rule.
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\4\ Hazardous Materials: Miscellaneous Amendments Pertaining to
DOT Specification Cylinders (RRR) (HM-234) [81 FR 48977], available
at https://www.gpo.gov/fdsys/pkg/FR-2016-07-26/pdf/2016-16689.pdf.
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Given the known risks associated with cylinders that are filled
with liquefied flammable compressed gases, PHMSA is issuing this
revised safety advisory notice to advise offerors and transporters of
DOT-39 cylinders that those with an internal volume greater than 75
in\3\ (1.23 L) should not be filled and/or transported with liquefied
compressed cyclopropane, ethane, or ethylene, or with liquefied
petroleum gases.
Issued in Washington, DC, on March 16, 2017.
William S. Schoonover,
Associate Administrator for Hazardous Materials Safety, Pipeline and
Hazardous Materials Safety Administration.
[FR Doc. 2017-05614 Filed 4-21-17; 8:45 am]
BILLING CODE 4910-60-P