18446 Federal Register / Vol. 72, No. 70 / Thursday, April 12, 2007 / Proposed Rules 

any additional enforceable duty beyond 

that required by state law, it does not 

contain any unfunded mandate or 

significantly or uniquely affect small 

governments, as described in the 

Unfunded Mandates Reform Act of 1995 

(Pub. L. 104–4). This proposed rule also 

does not have a substantial direct effect 

on one or more Indian tribes, on the 

relationship between the Federal 

Government and Indian tribes, or on the 

distribution of power and 

responsibilities between the Federal 

Government and Indian tribes, as 

specified by Executive Order 13175 (65 

FR 67249, November 9, 2000), nor will 

it have substantial direct effects on the 

States, on the relationship between the 

national government and the States, or 

on the distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132 (64 FR 43255, 

August 10, 1999), because it merely 

proposes to approve a state rule 

implementing a Federal requirement, 

and does not alter the relationship or 

the distribution of power and 

responsibilities established in the Clean 

Air Act. This proposed rule also is not 

subject to Executive Order 13045 (62 FR 

19885, April 23, 1997), because it 

approves a state rule implementing a 

Federal standard. 

In reviewing SIP submissions, EPA’s 

role is to approve state choices, 

provided that they meet the criteria of 

the Clean Air Act. In this context, in the 

absence of a prior existing requirement 

for the State to use voluntary consensus 

standards (VCS), EPA has no authority 

to disapprove a SIP submission for 

failure to use VCS. It would thus be 

inconsistent with applicable law for 

EPA, when it reviews a SIP submission, 

to use VCS in place of a SIP submission 

that otherwise satisfies the provisions of 

the Clean Air Act. Redesignation is an 

action that affects the status of a 

geographical area and does not impose 

any new requirements on sources. Thus, 

the requirements of section 12(d) of the 

National Technology Transfer and 

Advancement Act of 1995 (15 U.S.C. 

272 note) do not apply. As required by 

section 3 of Executive Order 12988 (61 

FR 4729, February 7, 1996), in issuing 

this proposed rule, EPA has taken the 

necessary steps to eliminate drafting 

errors and ambiguity, minimize 

potential litigation, and provide a clear 

legal standard for affected conduct. EPA 

has complied with Executive Order 

12630 (53 FR 8859, March 15, 1988) by 

examining the takings implications of 

the rule in accordance with the 

‘‘Attorney General’s Supplemental 

Guidelines for the Evaluation of Risk 

and Avoidance of Unanticipated 

Takings’’ issued under the executive 

order. 

This rule, proposing to approve the 

redesignation of the Richmond Area to 

attainment for the 8-hour ozone 

NAAQS, the associated maintenance 

plan, the 2002 base-year inventory, and 

the MVEBS identified in the 

maintenance plan, does not impose an 

information collection burden under the 

provisions of the Paperwork Reduction 

Act of 1995 (44 U.S.C. 3501 et seq.). 

List of Subjects 

40 CFR Part 52 

Environmental protection, Air 

pollution control, Nitrogen dioxide, 

Ozone, Reporting and recordkeeping 

requirements, Volatile organic 

compounds. 

40 CFR Part 81 

Air pollution control, National parks, 

Wilderness areas. 

Authority: 42 U.S.C. 7401 et seq. 

Dated: April 5, 2007. 

Judith Katz, 

Acting Regional Administrator, Region III. 

[FR Doc. E7–7018 Filed 4–11–07; 8:45 am] 

BILLING CODE 6560–50–P 

DEPARTMENT OF TRANSPORTATION 

Pipeline and Hazardous Materials 

Safety Administration 

49 CFR Parts 107, 171, 172, 173, 176, 

178, and 180 

[Docket No. PHMSA–2006–25910 (HM–

218E)] 

RIN: 2137–AE23 

Hazardous Materials: Miscellaneous 

Cargo Tank Motor Vehicle and Cylinder 

Issues; Petitions for Rulemaking 

AGENCY: Pipeline and Hazardous 

Materials Safety Administration 

(PHMSA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: PHMSA proposes to amend 

the Hazardous Materials Regulations 

(HMR; 49 CFR Parts 171–180) to revise 

certain requirements applicable to the 

manufacture, maintenance, and use of 

DOT and MC specification cargo tank 

motor vehicles, DOT specification 

cylinders and UN pressure receptacles. 

The proposed revisions are based on 

petitions for rulemaking submitted by 

the regulated community and are 

intended to enhance the safe 

transportation of hazardous materials in 

commerce, clarify regulatory 

requirements, and reduce operating 

burdens on cargo tank and cylinder 

manufacturers, requalifiers, carriers, 

shippers, and users. 

DATES: Comments must be received by 

June 11, 2007. 

ADDRESSES: You may submit comments 

identified by the docket number 

PHMSA–2006–25910 (HM–218E) by any 

of the following methods: 

• Federal eRulemaking Portal: http:// 

www.regulations.gov. Follow the 

instructions for submitting comments. 

• Web Site: http://dms.dot.gov. 

Follow the instructions for submitting 

comments on the DOT electronic docket 

site. 

• Fax: 1–202–493–2251. 

• Mail: Docket Management System; 

U.S. Department of Transportation, 400 

Seventh Street, SW., Nassif Building, 

Room PL–401, Washington, DC 20590–

001. 

• Hand Delivery: To the Docket 

Management System; Room PL–401 on 

the plaza level of the Nassif Building, 

400 Seventh Street, SW., Washington, 

DC between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal 

Holidays. 

Instructions: You must include the 

agency name and docket number 

PHMSA–2006–25910 (Docket No. HM–

218E) or the Regulatory Identification 

Number (RIN) for this notice of 

proposed rulemaking at the beginning of 

your comment. Please note that all 

comments received will be posted 

without change to http://dms.dot.gov 

including any personal information 

provided. See the Privacy Act section of 

this document. 

Docket: You may view the public 

docket through the Internet at http:// 

dms.dot.gov, or in person at the Docket 

Management System office at the above 

address. 

FOR FURTHER INFORMATION CONTACT: 

Cameron Satterthwaite or T. Glenn 

Foster, Office of Hazardous Materials 

Standards, Pipeline and Hazardous 

Materials Safety Administration, U.S. 

Department of Transportation, 400 

Seventh Street, SW., Washington, DC 

20590–0001, telephone (202) 366–8553. 

SUPPLEMENTARY INFORMATION: 

I. Background 

The Administrative Procedure Act 

(APA) requires Federal agencies to give 

interested persons the right to petition 

for the issuance, amendment, or repeal 

of a rule (5 U.S.C. 553(e)). PHMSA’s 

rulemaking procedure regulations, at 49 

CFR 106.95, provide for persons to ask 

PHMSA to add, amend or delete a 

regulation by filing a petition for 


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rulemaking containing adequate support 

for the requested action. In this NPRM, 

PHMSA (also ‘‘we’’ or ‘‘us’’) proposes to 

amend the HMR based on petitions for 

rulemaking submitted by cargo tank and 

cylinder manufacturers, requalifiers, 

shippers, and carriers. We are also 

proposing revisions to address requests 

for clarification of the regulations. These 

proposed revisions are intended to 

enhance the safe transportation of 

hazardous materials in cargo tank motor 

vehicles and cylinders, clarify 

regulatory requirements, and reduce 

operating burdens on carriers, shippers, 

and users. 

II. Summary of Proposals in This 

NPRM 

The development of this rulemaking 

was influenced by a wide array of 

correspondence received from persons 

engaged in the manufacture, 

maintenance, or use of cargo tanks and 

cylinders. We received petitions for 

rulemaking requesting changes to the 

cargo tank and cylinder requirements 

specified in the HMR and clarification 

of existing requirements. These 

petitions are summarized and discussed 

in the following review-by-section 

summary: 

A. Part 171 

Updated/Revised/Added Incorporations 

by Reference (§ 171.7) 

We have reviewed the following 

documents pertaining to cargo tanks and 

compressed gas cylinders. As a result, 

we have found no provisions that would 

impose a substantial burden or would 

have an adverse impact on safety. 

Therefore, we are proposing to update, 

revise, and add the following 

incorporation by reference (IBR) 

materials in paragraph (a)(3) of § 171.7 

in the Table of material incorporated by 

reference: 

• In response to Western Growers 

Association (WGA) petition P–1352, 

under the entry ‘‘American Society of 

Mechanical Engineers,’’ we propose to 

revise the reference for ‘‘ASME Code, 

Sections II (Parts A and B), V, VIII 

(Division 1), and IX of 1998 Edition of 

American Society of Mechanical 

Engineers Boiler and Pressure Vessel 

Code’’ to add a section reference for 

§ 173.5b. See review-by-section 

preamble discussion in § 173.5b for 

further details. 

• In response to WGA petition P–

1352, under the entry ‘‘American 

Society for Testing and Materials,’’ we 

propose to add references to ASTM 

A53/A53M–06a and ASTM A106/ 

A106M–06a. See review-by-section 

preamble discussion in § 173.5b for 

further details. 

• In response to Compressed Gas 

Association (CGA) petition P–1482, 

under the entry ‘‘Compressed Gas 

Association, Inc,’’ we propose to add a 

reference to CGA, C–1 ‘‘Methods for 

Hydrostatic Testing of Compressed Gas 

Cylinders,’’ 2004 edition. See review-bysection preamble discussion in 

§ 180.205 for further details. 

• In response to CGA petition P–

1489, under the entry ‘‘Compressed Gas 

Association, Inc,’’ we propose to update 

CGA G–2.2, ‘‘Guideline Method for 

Determining Minimum of 0.2% Water in 

Anhydrous Ammonia,’’ from the 1985 

Edition to reflect the 1985 Second 

Edition, Reaffirmed 1997. Paragraph (l), 

in § 173.315, restricts the use of MC 330 

and MC 331 cargo tanks constructed of 

quenched and tempered ‘‘QT’’ steel 

from transporting anhydrous ammonia 

unless the ammonia has the specified 

minimum water content. The analysis of 

the water content in the ammonia is 

conducted as prescribed in CGA G–2.2. 

Currently, CGA G–2.2, 1985, Second 

Edition is incorporated by reference in 

§ 171.7(a)(3). CGA reaffirmed this 

publication in 1997. There were no 

changes to the document other than the 

title reflecting that it was reaffirmed in 

1997. 

• In response to CGA petition P–

1488, under the entry ‘‘Compressed Gas 

Association, Inc,’’ we propose to update 

CGA P–20, ‘‘Standard for Classification 

of Toxic Gas Mixtures’’ from the 1995 

2nd edition to the 2003 3rd edition. See 

review-by-section preamble discussion 

in § 173.115 for further details. 

• In response to CGA petition P–

1484, under the entry ‘‘Compressed Gas 

Association, Inc,’’ we propose to add a 

reference to CGA TB–25 ‘‘Design 

Considerations for Tube Trailers,’’ 2005 

edition. See review-by-section preamble 

discussion in § 173.301 for further 

details. 

• In response to CGA petition P–

1422, under the entry ‘‘Compressed Gas 

Association, Inc,’’ we propose to add a 

reference to CGA V–9 ‘‘Standard for 

Compressed Gas Cylinder Valves,’’ 2005 

edition. See review-by-section preamble 

discussion in §§ 173.40 and 173.301 for 

further details. 

In response to Tank Trailer 

Manufacturers Association (TTMA) 

petition P–1408, we are also proposing 

to revise paragraph (b) of § 171.7, List of 

informational materials not requiring 

incorporation by reference, to add a 

reference to TTMA RP No. 96–01, 

‘‘Structural Integrity of DOT 406, DOT 

407, and DOT 412 Cylindrical Cargo 

Tanks, January 1, 2001 Edition.’’ See 

review-by-section preamble discussion 

in § 178.345–3 for further details. 

B. Part 173 

Mobile Refrigeration Systems (§ 173.5b) 

The agricultural produce industry 

uses large, mobile refrigeration systems 

on field sites to help preserve freshly 

harvested fruit and vegetables. These 

refrigeration systems consist of ASME 

non-DOT specification pressure 

components with a maximum total 

volumetric capacity per vehicle of 2,500 

gallons. Refrigerant systems placed in 

service prior to June 1, 1991, have a 

maximum allowable working pressure 

(MAWP) between 150 to 250 psig; and 

those placed in service on or after June 

1, 1991, have an MAWP of 250 psig. The 

refrigeration system, commonly known 

as vacuum tubes, accumulators, 

refrigeration units, icemakers, pressure 

coolers or evaporators, primarily use 

Division 2.2 refrigerant gases or 

anhydrous ammonia in the cooling 

process. The refrigeration systems may 

or may not be mounted on a motor 

vehicle. These refrigerant systems are 

operated under special permit, SP–

10285, which requires each refrigeration 

system to be visually inspected annually 

and proof pressure tested at least once 

every two years. The Western Growers 

Association (WGA) P–1352 requests we 

establish design and safety control 

measures for these refrigeration systems 

consistent with those specified in the 

special permit and provide for their use 

in the HMR. WGA states these 

refrigeration systems have been 

authorized under DOT–SP 10285 for 

highway transportation since 1989 and 

have an exceptional transportation 

safety record. WGA conservatively 

estimates that in a two-month period, 

these refrigeration systems cool over 

18,000,000 cartons of produce valued at 

more than $56 million. We agree with 

WGA that these portable refrigeration 

systems have a proven safety record 

under the special permit. Therefore, we 

propose to add a new § 173.5b to 

authorize the transportation of these 

refrigeration systems subject to the 

design and safety control measures 

recommended in the petition and 

prescribed in DOT–SP 10285. 

Standards for Cylinder Valves 

(§§ 173.40 and 173.301) 

Currently, § 173.40(c) of the HMR 

requires each cylinder containing a 

poison inhalation hazard (PIH) material 

in Hazard Zone A to be closed with a 

plug or valve having a taper-threaded 

connection. Each cylinder, with the 

plug or valve installed, must be capable 

of withstanding the cylinder test 


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pressure without damage or leakage, as 

specified in § 173.40(c). CGA (P–1422) 

requests we add a new paragraph (c)(5) 

to § 173.40 to require cylinders 

containing a Hazard Zone A material to 

be closed with a plug or a valve 

conforming to CGA V–9, ‘‘Compressed 

Gas Association Standard for 

Compressed Gas Cylinder Valves,’’ 2005 

edition. Section 173.301 prescribes 

general requirements for the shipment 

of compressed gases in cylinders and 

spherical vessels. CGA further requests 

we revise § 173.301(c) to require 

cylinders containing Hazard Zone A and 

B toxic gases and mixtures to meet the 

requirements in CGA V–9. CGA V–9 

defines a cylinder valve as the 

mechanical device attached to a 

compressed gas cylinder that permits 

flow into or out of the cylinder when 

the device is in the open position, and 

prevents flow when it is in the closed 

position. CGA V–9 contains standards 

on general cylinder valve design, design 

qualification, and performance 

requirements such as operating 

temperature limits, pressure ranges, and 

flow capabilities. This standard also 

contains testing and maintenance 

requirements to ensure valves are 

maintained in a safe working condition. 

CGA V–9 is not applicable to cylinder 

valves used on non-refillable cylinders 

whose valves or inlet connections are 

permanently attached to the cylinders 

by means of welding or brazing, or to 

valves on cylinders that are horizontally 

mounted to a chassis or framework for 

road transportation. CGA states use of 

this publication will provide greater 

assurance that valves used on cylinders 

containing toxic materials are in good 

condition and properly maintained. 

Based on our review of CGA V–9, we 

agree with CGA that providing for the 

use of CGA V–9 will assist shippers in 

the proper selection and use of valves 

installed in DOT specification cylinders 

containing toxic and various types of 

other gases. Because gases vary in 

degrees of corrosivity, toxicity, and 

pressure and concentration, a user must 

use care in selecting a cylinder valve 

appropriate for the cylinder’s intended 

use and pressure. The current HMR 

offer no guidance to users on the proper 

selection of valves. Therefore, we 

propose to revise §§ 173.40(c) and 

173.301(a) to require valves on 

cylinders, unless otherwise excepted, to 

conform to the requirements in CGA V–

9, ‘‘Standard for Compressed Gas 

Cylinder Valves,’’ 2005 Fifth Edition. 

We also solicit comments on the 

potential cost impacts, if any, of 

requiring compliance with CGA V–9. 

Classification Criteria for Toxic Gas 

Mixtures (§ 173.115) 

In § 173.155(c)(2), the definition for 

Division 2.3 material (gas poisonous by 

inhalation) provides that LC50 values for 

mixtures may be determined using the 

formula in § 173.133(b)(1)(i) or CGA P–

20, ‘‘Standard for Classification of Toxic 

Gas Mixtures.’’ CGA (P–1488) requests 

we update CGA P–20 from the 1995 2nd 

edition to the 2003 3rd edition. CGA 

enclosed a list of changes contained in 

the 3rd edition. These changes align the 

LC50 values contained in CGA P–20 

with values contained in the 

international standards for the following 

materials: Ethylene oxide, Hydrogen 

fluoride, Methyl amine, Nitrogen 

trioxide, Phosphorous pentafluoride, 

Phosphorous trifluoride, and Tungsten 

hexafluoride. We agree the petition has 

merit and propose to revise paragraph 

(c)(2) to reflect the updated CGA P–20, 

‘‘Standard for Classification of Toxic 

Gas Mixtures.’’

Tube Trailers (§ 173.301) 

This section prescribes general 

requirements for the shipment of 

compressed gases in cylinders and 

spherical pressure vessels. Paragraph (i) 

of § 173.301 specifies guidelines for 

cylinders mounted on motor vehicles or 

in frames, commonly referred to as tube 

trailers. CGA (P–1484) requests we 

revise § 73.301(i) to reference the 

technical bulletin, CGA TB–25, ‘‘Design 

Considerations for Tube Trailers,’’ 2005 

edition. CGA TB–25 addresses 

protective structures for valves and 

pressure relief devices, and design 

considerations for the static, dynamic, 

and thermal loads affecting tube trailers. 

These design considerations are 

intended to reduce the likelihood of the 

tube separating from the trailer and to 

minimize the unintentional release of 

hazardous materials in the event of a 

highway collision, including but not 

limited to, a rollover accident. These 

guidelines are intended to promote the 

reliable operation of the trailers under 

normal conditions and minimize the 

risk of a catastrophic incident in the 

event of an accident. 

We agree the guidelines contained in 

CGA TB–25 will enhance the safe 

transportation of tube trailers. CGA 

developed TB–25 to address safety 

concerns identified following a May 1, 

2001 hydrogen gas tube trailer incident 

investigated by the National 

Transportation Safety Board (NTSB). In 

the incident, certain horizontally 

mounted cylinders on a semi-trailer, 

along with valves, piping and fittings, 

were damaged, causing the release of 

hydrogen gas. As a result, NTSB made 

several recommendations to PHMSA in 

an effort to address safety concerns. 

PHMSA responded to NTSB 

Recommendation H–02–25 by revising 

ERG Guide 115 in the 2004 Emergency 

Response Guidebook to include 

information on the difficulty of 

detecting and extinguishing hydrogenfuel fires. As a result, NTSB classified 

Safety Recommendation H–02–25 as 

‘‘Closed—Acceptable Action.’’ NTSB 

also recommended that PHMSA revise 

§ 173.301 to clearly require valves, 

piping, and fittings for cylinders that are 

horizontally mounted and used to 

transport hazardous materials to be 

protected from multidirectional forces 

that are likely to occur during accidents, 

including rollovers (NTSB 

Recommendation H–02–23); and to 

require cylinders that are used to 

transport hazardous materials and are 

horizontally mounted on a semi-trailer 

to be protected from impact with the 

roadway or terrain to reduce the 

likelihood of their being fractured and 

ejected during a rollover accident 

(NTSB Recommendation H–02–24). 

Accordingly, we propose to revise 

§ 173.301(i) to require tube trailers to 

conform to the requirements in CGA 

TB–25, ‘‘Design Considerations for Tube 

Trailers.’’ We also solicit comments on 

the potential cost impacts, if any, of 

requiring compliance with CGA TB–25. 

Requalification of DOT 3BN Cylinders 

(§ 173.338) 

Section 173.338 authorizes the use of 

DOT 3BN cylinders for the shipment of 

tungsten hexafluoride. Section 173.163 

permits cylinders used exclusively for 

hydrogen fluoride to be requalified by 

external visual inspection in place of 

the periodic volumetric expansion test. 

Air Products (P–1458) requests we 

permit DOT 3BN cylinders used 

exclusively for tungsten hexafluoride to 

be requalified by an external visual 

inspection in place of the volumetric 

expansion test. Air Products states the 

chemical and physical properties of 

tungsten hexafluoride are similar to 

those of hydrogen fluoride. Air Products 

states noble metal nickel 200 does not 

corrode in tungsten hexafluoride service 

and the company has never had a 

cylinder fail a volumetric expansion 

test. We agree with the petitioner that 

the chemical properties of tungsten 

hexafluoride are similar to those of 

hydrogen fluoride. Tungsten 

hexafluoride does not corrode nickel; 

therefore, an internal inspection is not 

warranted. We have authorized DOT 

3BN cylinders used exclusively for 

tungsten hexafluoride to be requalified 

by an external visual inspection for 

several years under special permit, SP–


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14016, with satisfactory transportation 

experience. SP–14016 stipulates that 

DOT 3BN cylinders removed from 

service must be condemned. Therefore, 

in § 173.338, we propose to permit DOT 

3BN cylinders used exclusively for 

tungsten hexafluoride to be requalified 

by an external visual inspection in place 

of the volumetric expansion test. The 

cylinders must be condemned when 

removed from service. 

C. Part 176 

Stowage Requirements for Class 2 

Material on Vessels (§ 176.200) 

Section 176.200 prescribes general 

stowage requirements for Class 2 

(Compressed gases) materials 

transported aboard vessels. Horizon 

Lines (P–1471) requests we prohibit 

vessel stowage of Division 2.1 

(flammable gases) in ‘‘reefer units,’’ that 

is, powered refrigerated temperature 

controlled containers. Horizon Lines 

expresses concern that sparks emitted 

from mechanical components of the 

reefer unit could come into contact with 

flammable gas in the event of a spill and 

cause an explosion. Horizon Lines 

further states its concern was 

substantiated by several major 

manufacturers of reefer units. We agree 

with the petitioner that the stowage of 

flammable gases in powered refrigerated 

temperature controlled containers 

should not be permitted without 

adequate safety measures. The transport 

of hazardous materials in temperature 

controlled containers is addressed in 

Chapter 7 of the International Maritime 

Dangerous Goods (IMDG) Code. More 

specifically, the IMDG Code, at 7.4 and 

7.7 requires the use of refrigeration 

systems with explosion-proof electric 

fittings within the cooling compartment 

to prevent ignition of flammable vapors. 

Consistent with the IMDG Code, we 

propose to revise § 176.200 (f) to restrict 

any package containing a Division 2.1 

material from transportation in powered 

refrigerated temperature controlled 

containers, unless the container 

equipment is capable of preventing 

ignition of flammable vapor by having 

non-sparking or explosion-proof electric 

fittings within the cooling compartment. 

D. Part 178 

DOT 4E Cylinders (§ 178.68) 

Section 178.68 contains the 

manufacturing specification for DOT 4E 

welded aluminum cylinders. Paragraph 

(l)(2) specifies the guided bend test 

procedures and rejection criteria to be 

applied to welds. Worthington 

Cylinders Corp (Worthington) (P–1486) 

requests we revise this paragraph to 

authorize the use of an alternate bend 

test illustrated in paragraph 12 of The 

Aluminum Association’s publication, 

‘‘Welding Aluminum: Theory and 

Practice’’ for determining the soundness 

of circumferential seam welds on 

aluminum cylinders. Worthington states 

use of this alternate test will assure the 

stress is placed on the weld, rather than 

the heat-affected zone of the weld. We 

agree that this alternate bend test is an 

acceptable test method for aluminum 

cylinders, as well as the currently 

authorized bend test designed for thinwalled steel cylinders. Therefore, we are 

proposing to revise § 178.68(l) to allow 

the bend test described in The 

Aluminum Association’s publication, 

‘‘Welding Aluminum: Theory and 

Practice,’’ as an alternative test method. 

DOT 406, 407, and 412 Cargo Tank 

Motor Vehicles (§ 178.345–3) 

Section 178.345–3 prescribes 

structural integrity requirements for the 

design and construction of DOT 406, 

DOT 407, and DOT 412 cargo tank 

motor vehicles. Paragraph (a) specifies 

the general requirements and 

acceptance criteria for structural 

integrity. The Tank Trailer 

Manufacturers Association (TTMA) (P–

1408) requests we revise paragraph (a) 

to reference TTMA Recommended 

Practice (RP) No. 96–97, ‘‘Structural 

Integrity of DOT 406, DOT 407, and 

DOT 412 Cylindrical Cargo Tanks,’’

December 1, 1997 Edition. This 

standard contains methods for 

calculating the structural integrity of 

DOT 406, DOT 407 and DOT 412 

cylindrical cargo tanks in conformance 

with §§ 178.345–3 and 178.345–8(e). 

Based on the Federal Motor Carrier 

Safety Administration’s review of 

TTMA RP No. 96–97, we agree with the 

petitioner that using the methods 

outlined in the publication for 

calculating the structural integrity of 

cargo tanks will be beneficial to 

manufacturers in reducing time to 

perform the calculations. Therefore, we 

propose to revise § 178.345–3(a)(3) to 

reference the updated TTMA RP 96–01, 

2001 Edition, as suitable guidance for 

performing the structural integrity 

calculations. 

Manhole Assemblies on DOT 406, 407, 

and 412 Cargo Tank Motor Vehicles 

(§ 178.345–5) 

Section 178.345–5 prescribes 

requirements for manhole assemblies 

used on DOT 406, DOT 407, and DOT 

412 cargo tank motor vehicles. 

Paragraph (f) specifies that all fittings 

and devices mounted on a manhole 

cover, coming in contact with the 

lading, must withstand the same static 

internal fluid pressure and contain the 

same permanent compliance markings 

as those prescribed in paragraph (e) for 

the manhole cover. Because paragraph 

(e) already requires the manhole cover 

to be marked with a statement certifying 

that the manhole cover meets the 

requirements in § 178.345–5, TTMA (P–

1372) requests we remove the marking 

requirement in paragraph (f). We agree 

with the petitioner that the requirement 

in § 178.345–5(f) to mark the manhole’s 

fittings is duplicative of the manhole 

cover marking requirement in paragraph 

(e). Therefore, we propose to remove the 

redundant wording in paragraph (f). 

E. Part 180 

Cylinder Requalification (§ 180.205) 

Section 180.205 prescribes general 

requirements for requalification of DOT 

specification cylinders and special 

permit cylinders. Paragraph (g) contains 

requirements for conducting a periodic 

pressure test for the requalification of 

cylinders. These requirements include 

parameters for accuracy of the test 

equipment. CGA requests we revise 

paragraph (g) to reference CGA C–1 

‘‘Methods for Hydrostatic Testing of 

Compressed Gas Cylinders,’’ 2004 

edition. This CGA publication contains 

hydrostatic testing requirements for the 

requalification of cylinders. 

We agree the CGA publication more 

adequately reflects the equipment 

accuracy requirements for performing a 

pressure test on cylinders. We propose 

to revise § 180.205(g) to reference CGA 

C–1 for requalification of DOT 

specification cylinders. Section 180.207 

covering UN pressure receptacles also 

references § 180.205(g) for test 

equipment accuracy. We propose to 

retain the current requirement in 

paragraph (g) that permits a pressure 

test to be repeated, in the event of test 

equipment failure only, at a pressure 

increased by 10%, or 100 psi, whichever 

is the lower value. If repeated, the 

cumulative increase in test pressure 

may not exceed 10% of minimum 

prescribed test pressure, as noted in 

CGA C–1. As an example, using a 

cylinder marked ‘‘DOT3AA1800’’, if the 

first test is performed exactly at the 

minimum test pressure of 3000 psi (5/ 

3 service pressure), and subsequent tests 

exactly at 3100, 3200, and 3300, a total 

of three repeat tests could be performed. 

However, if the first test is performed at 

3200, one repeat test could be 

performed at 3300. The proposed rule 

does not alter any of the requirements 

for the operator to ensure the test system 

is accurate and ready to test cylinders. 

We are retaining the requirements 

contained in current paragraph (g) 

concerning bands and other removable 


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attachments, allowing other calibration 

standards approved by the Associate 

Administrator, requiring the requalifier 

to demonstrate calibration to an 

authorized DOT inspector, and the 

retention of calibrated cylinder 

certificates. 

Cargo Tank Testing and Inspection 

(§ 180.407) 

Section 180.407 prescribes 

requirements for the periodic testing 

and inspection of specification cargo 

tanks. Paragraph (d)(3) of § 180.407 

requires each reclosing pressure relief 

valve that is required to be removed and 

tested to be able to open at the required 

set pressure and reseat to a leak-tight 

condition at 90 percent of the set-todischarge pressure or the pressure for 

the applicable cargo tank specification. 

Paragraph (g)(1)(ii)(A) of § 180.407 

requires each self-closing pressure relief 

valve that is an emergency relief vent to 

open at the required set pressure and 

seat to a leak-tight condition at 90 

percent of the set-to-discharge pressure 

or the pressure for the applicable cargo 

tank specification. Keehn Service 

Corporation (Keehn Service) (P–1436) 

states the majority of pressure relief 

valves installed on MC–330 and MC–

331 cargo tank motor vehicles 

transporting liquefied petroleum gas 

have a start-to-discharge set pressure of 

250 psi. Keehn Service states it is 

difficult for existing or rebuilt valves to 

open at this exact pressure. In fact, a 

margin of error of as much as 4 psig 

could occur when using a typical 0–400 

psig pressure gauge. Keehn Service 

requests we specify a start-to-discharge 

tolerance for pressure relief valves. We 

agree with the petitioner that it may be 

difficult for a pressure relief valve to 

function exactly at the specified set 

pressure and that we should allow a 

margin of error. Therefore, we propose 

to revise paragraphs (d)(3) and 

(g)(1)(ii)(A), of § 180.407, to specify that 

reclosing and self-closing pressure relief 

valves must be set-to-discharge at a 

pressure no more than 110% of the 

required set pressure. Providing for a 

tolerance is consistent with the set-todischarge tolerance allowed for certain 

other DOT specification pressure 

vessels. 

III. Regulatory Analyses and Notices 

A. Statutory/Legal Authority for This 

Rulemaking 

This notice is published under 

authority of 49 U.S.C. 5103(b), which 

authorizes the Secretary of 

Transportation to prescribe regulations 

for the safe transportation, including 

security, of hazardous material in 

intrastate, interstate, and foreign 

commerce. This notice proposes to 

adopt regulations intended to enhance 

the safe transportation of hazardous 

materials in cargo tank motor vehicles 

and cylinders, clarify regulatory 

requirements, and reduce operating 

burdens on carriers, shippers, and users. 

B. Executive Order 12866 and DOT 

Regulatory Policies and Procedures 

This notice of proposed rulemaking is 

not considered a significant regulatory 

action under section 3(f) of Executive 

Order 12866 and, therefore, was not 

reviewed by the Office of Management 

and Budget (OMB). This rule is not 

significant under the Regulatory Policies 

and Procedures of the Department of 

Transportation (44 FR 11034). 

The proposed rule addresses several 

petitions for rulemaking submitted by 

the regulated community. For the most 

part, the petitioners request revisions to 

the HMR that should reduce overall 

compliance costs. For example, several 

of the petitioners request we update 

industry consensus standards 

incorporated by reference into the HMR. 

Adoption of industry standards reduces 

the regulatory burden on persons who 

offer hazardous material for 

transportation and persons who 

transport hazardous materials in 

commerce. Industry standards 

developed and adopted by consensus 

generally are accepted and followed by 

the industry; thus, their incorporation 

by reference in the HMR assures that the 

industry is not forced to comply with a 

different set of standards to accomplish 

the same safety goal. In addition, several 

of the petitions request regulatory relief 

through alternative means of 

compliance with current safety 

regulations or the elimination of 

requirements that are duplicative, outdated, or otherwise unnecessary for 

safety. Thus, we are proposing to 

eliminate a duplicative marking 

requirement for manholes on certain 

cargo tank motor vehicles and provide 

alternative manufacturing and 

requalification methods for certain 

cylinders and cargo tank motor vehicles. 

Two of the proposals in this NPRM 

may result in increased compliance 

costs on the regulated community. We 

are proposing to require valves on 

cylinders authorized for the 

transportation of hazardous materials to 

conform to requirements in a CGA 

consensus standard—CGA V–9—

applicable to compressed gas cylinder 

valves. Use of the CGA standard will 

help shippers to select a valve that is 

appropriate for the cylinder’s intended 

use and pressure. Use of the correct 

valve is critical to prevent leaks or 

failures during transportation. We 

believe that most cylinder users already 

use the CGA consensus standard to 

guide their valve selection decisions; 

thus, we expect increased compliance 

costs associated with this proposal to be 

minimal. However, we request 

comments on the potential costs and 

impacts of requiring compliance with 

the valve requirements in CGA V–9. 

In addition, we are proposing to 

address a safety problem involving the 

transportation of hazardous materials in 

tube trailers through adoption of CGA 

consensus standard TB–24, ‘‘Design 

Considerations for Tube Trailers.’’ The 

CGA standard addresses safety concerns 

identified by NTSB in its investigation 

of an accident involving tube trailers 

that resulted in the release of hydrogen 

gas. We anticipate transportation of 

hydrogen gas in tube trailers will 

increase significantly in the coming 

years to support its use as an alternative 

fuel for automobiles and other vehicles. 

Ensuring that hydrogen gas will be 

transported safely to suppliers and 

distribution centers will be essential to 

support its use as an alternative fuel. 

The CGA standard addresses protective 

structures for valves and pressure relief 

devices and design considerations for 

static, dynamic, and thermal loads 

affecting tube trailers. The standard is 

intended to reduce the likelihood of the 

tube trailer separating from its trailer 

and to prevent the unintentional release 

of hazardous materials in the event of a 

highway collision or rollover accident. 

Because we are proposing to adopt an 

industry consensus standard that is 

already in widespread use by the 

industry, we expect compliance costs 

associated with this proposal will be 

minimal. However, we request 

comments on the potential cost and 

other impacts of requiring compliance 

with the CGA standard. 

If adopted, the proposals in this 

NPRM will enhance transportation 

safety and may reduce the overall 

compliance burden on the regulated 

industry. 

C. Executive Order 13132 

This proposed rule has been analyzed 

in accordance with the principles and 

criteria contained in Executive Order 

13132 (‘‘federalism’’). This proposed 

rule would preempt State, local, and 

Indian tribe requirements but does not 

propose any regulation that has 

substantial direct effects on the States, 

the relationship between the national 

government and the States, or the 

distribution of power and 

responsibilities among the various 

levels of government. Therefore, the 


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consultation and funding requirements 

of Executive Order 13132 do not apply. 

The Federal hazardous materials 

transportation law, 49 U.S.C. 5101–

5127, contains an express preemption 

provision (49 U.S.C. 5125(b)) that 

preempts State, local, and Indian tribe 

requirements on certain covered 

subjects. Covered subjects are: 

(i) The designation, description, and 

classification of hazardous material; 

(ii) The packing, repacking, handling, 

labeling, marking, and placarding of 

hazardous material; 

(iii) The preparation, execution, and 

use of shipping documents related to 

hazardous material and requirements 

related to the number, contents, and 

placement of those documents; 

(iv) The written notification, 

recording, and reporting of the 

unintentional release in transportation 

of hazardous material; or 

(v) The design, manufacture, 

fabrication, inspection, marking, 

maintenance, reconditioning, repair, or 

testing of a packaging or container 

represented, marked, certified, or sold 

as qualified for use in transporting 

hazardous material in commerce. 

This proposed rule addresses covered 

subject items (v) above and preempts 

State, local, and Indian tribe 

requirements not meeting the 

‘‘substantively the same’’ standard. This 

proposed rule is necessary to update, 

clarify and provide relief from 

regulatory requirements. 

Federal hazardous materials 

transportation law provides at 

§ 5125(b)(2) that, if DOT issues a 

regulation concerning any of the 

covered subjects, DOT must determine 

and publish in the Federal Register the 

effective date of Federal preemption. 

The effective date may not be earlier 

than the 90th day following the date of 

issuance of the final rule and not later 

than two years after the date of issuance. 

PHMSA has determined the effective 

date of Federal preemption for these 

requirements will be 1 year from the 

date of publication of a final rule in the 

Federal Register. 

D. Executive Order 13084 

This proposed rule has been analyzed 

in accordance with the principles and 

criteria contained in Executive Order 

13084 (‘‘Consultation and Coordination 

with Indian Tribal Governments’’). 

Because this proposed rule does not 

significantly or uniquely affect the 

communities of the Indian tribal 

governments and does not impose 

substantial direct compliance costs, the 

funding and consultation requirements 

of Executive Order 13084 do not apply. 

E. Regulatory Flexibility Act, Executive 

Order 13272, and DOT Regulatory 

Policies and Procedures 

The Regulatory Flexibility Act (5 

U.S.C. 601 et seq.) requires an agency to 

review regulations to assess their impact 

on small entities unless the agency 

determines a rule is not expected to 

have a significant impact on a 

substantial number of small entities. 

The proposed rule incorporates several 

petitions for rulemaking submitted by 

the regulated community. As specified 

above, there may be minimal increased 

costs associated with the adoption of 

CGA V–9 and CGA TB–24. However, the 

revisions as a whole proposed in this 

rulemaking, if adopted, may decrease 

overall compliance costs for the 

regulated community while enhancing 

the safe transportation of hazardous 

materials in commerce. Therefore, I 

certify this rule should not have a 

significant economic impact on a 

substantial number of small entities. 

This notice has been developed in 

accordance with Executive Order 13272 

(‘‘Proper Consideration of Small Entities 

in Agency Rulemaking’’) and DOT’s 

procedures and policies to promote 

compliance with the Regulatory 

Flexibility Act to ensure potential 

impacts of draft rules on small entities 

are properly considered. 

F. Paperwork Reduction Act 

PHMSA currently has approved 

information collections under Office of 

Management and Budget (OMB) Control 

Number 2137–0014, ‘‘Cargo Tank 

Specification Requirements,’’ with an 

expiration date of November 30, 2007, 

and Control Number 2137–0022, 

‘‘Testing, Inspection, and Marking 

Requirements for Cylinders,’’ with an 

expiration date of August 31, 2008. This 

rule proposes no new information 

collection and recordkeeping 

requirements. 

Title 5, Code of Federal Regulations 

requires us to provide interested 

members of the public and affected 

agencies an opportunity to comment on 

information collection and 

recordkeeping requests. Under the 

Paperwork Reduction Act, no person is 

required to respond to an information 

collection unless it has been approved 

by OMB and displays a valid OMB 

control number. 

Requests for a copy of these 

information collections should be 

directed to Deborah Boothe or T. Glenn 

Foster, Office of Hazardous Materials 

Standards (DHM–10), Pipeline and 

Hazardous Materials Safety 

Administration, Room 8422, 400 

Seventh Street, SW., Washington, DC 

20590–0001, Telephone (202) 366–8553. 

All comments should be addressed to 

the Dockets Unit as identified in the 

ADDRESSES section, and received prior 

to the close of the comment period 

identified in the DATES section of this 

rulemaking. In addition, you may 

submit comments specifically related to 

the information collection burden to the 

PHMSA Desk Officer, Office of 

Management and Budget (OMB), at fax 

number 202–395–6974. Under the 

Paperwork Reduction Act of 1995, no 

person is required to respond to an 

information collection unless it displays 

a valid OMB control number. 

G. Regulation Identifier Number (RIN) 

A regulation identifier number (RIN) 

is assigned to each regulatory action 

listed in the Unified Agenda of Federal 

Regulations. The Regulatory Information 

Service Center publishes the Unified 

Agenda in April and October of each 

year. The RIN number contained in the 

heading of this document can be used 

to cross-reference this action with the 

Unified Agenda. 

H. Unfunded Mandates Reform Act 

This proposed rule imposes no 

unfunded mandates and thus does not 

impose unfunded mandates under the 

Unfunded Mandates Reform Act of 

1995. 

I. Privacy Act 

Anyone is able to search the 

electronic form of all comments 

received into any of our dockets by the 

name of the individual submitting the 

comment (or signing the comment, if 

submitted on behalf of an association, 

business, labor union, etc.). You may 

review DOT’s complete Privacy Act 

Statement in the Federal Register 

published on April 11, 2000 (Volume 

65, Number 70; Pages 19477–78) or you 

may visit http://dms.dot.gov. 

List of Subjects 

49 CFR Part 171 

Exports, Hazardous materials 

transportation, Hazardous waste, 

Imports, Incorporation by reference, 

Reporting and recordkeeping 

requirements. 

49 CFR Part 173 

Hazardous materials transportation, 

Incorporation by reference, Packaging 

and containers, Radioactive materials, 

Reporting and recordkeeping 

requirements, Uranium. 

49 CFR Part 176 

Hazardous materials transportation, 

Incorporation by reference, Maritime 


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carriers, Radioactive materials, 

Reporting and recordkeeping 

requirements. 

49 CFR Part 178 

Hazardous materials transportation, 

Motor vehicle safety, Packaging and 

containers, Reporting and recordkeeping 

requirements. 

49 CFR Part 180 

Hazardous materials transportation, 

Incorporation by reference, Motor 

carriers, Motor vehicle safety, Packaging 

and containers, Railroad safety, 

Reporting and recordkeeping 

requirements. 

In consideration of the foregoing, 49 

CFR Chapter I is proposed to be 

amended as follows: 

PART 171—GENERAL INFORMATION, 

REGULATIONS, AND DEFINITIONS 

1. The authority citation for part 171 

continues to read as follows: 

Authority: 49 U.S.C. 5101–5128, 44701; 49 

CFR 1.45 and 1.53; Pub. L. 101–410 section 

4 (28 U.S.C. 2461 note); Pub L. 104–134 

section 31001. 

2. In § 171.7, make the following 

changes: 

a. In the table in paragraph (a)(3), 

under The Aluminum Association, a 

new entry titled ‘‘Welding Aluminum: 

Theory and Practice,’’ 2002 Fourth 

Edition is added; 

b. In the table in paragraph (a)(3), 

under American Society of Mechanical 

Engineers, the entry titled ‘‘ASME Code, 

Sections II (Parts A and B), V, VIII 

(Division 1), and IX of 1998 Edition of 

American Society of Mechanical 

Engineers Boiler and Pressure Vessel 

Code,’’ is revised; 

c. In the table in paragraph (a)(3), 

under American Society for Testing and 

Materials, entries for ASTM A53/ 

A53M–06a and ASTM A106/A106M–

06a are added; 

d. In the table in paragraph (a)(3), 

under Compressed Gas Association, 

Inc., entries for CGA Pamphlet G–2.2 

1985 edition and CGA Pamphlet P–20 

1995 edition are revised; 

e. In the table in paragraph (a)(3), 

under Compressed Gas Association Inc., 

new entries for CGA C–1 2005 edition, 

CGA TB–25 2005 edition, and CGA V–

9 2005 edition are added; and 

f. In paragraph (b), a new entry 

‘‘Truck Trailer Manufacturers 

Association,’’ 1020 Princess Street, 

Alexandria, Virginia 22314, ‘‘TTMA RP 

No. 96–01,’’ January 1, 2001 Edition is 

added in alphabetical order. 

The revisions and additions read as 

follows: 

§ 171.7 Reference material. 

(a) * * * 

(3) Table of material incorporated by 

reference. * * * 

Source and name of material 49 CFR reference 

* * * * * * * 

The Aluminum Association, 

* * * * * * * 

Welding Aluminum: Theory and Practice, 2002 Fourth Edition ........ 178.68. 

* * * * * * * 

American Society of Mechanical Engineers, 

* * * * * * * 

ASME Code, Sections II (Parts A and B), V, VIII (Division 1), and 

IX of 1998 Edition of American Society of Mechanical Engineers 

Boiler and Pressure Vessel Code.

172.102; 173.5b; 173.24b; 173.32; 173.306; 173.315; 173.318; 

173.420; 178.245–1; 178.245–3; 178.245–4; 178.245–6; 178.245–7; 

178.255–1; 178.255–2; 178.255–14; 178.255–15; 178.270–2; 

178.270–3; 178.270–7; 178.270–9; 178.270–11; 178.270–12; 

178.271–1; 178.272–1; 178.273; 178.274; 178.276; 178.277; 

178.320; 178.337–1; 178.337–2; 178.337–3; 178.337–4; 178.337–6; 

178.337–16; 178.337–18; 178.338–1; 178.338–2; 178.338–3; 

178.338–4; 178.338–5; 178.338–6; 178.338–13; 178.338–16; 

178.338–18; 178.338–19; 178.345–1; 178.345–2; 178.345–3; 

178.345–4; 178.345–7; 178.345–14; 178.345–15; 178.346–1; 

178.347–1; 178.348–1; 179.400–3; 180.407. 

* * * * * * * 

American Society for Testing and Materials, 

* * * * * * * 

ASTM A53/A53M–06a Standard Specification for Pipe, Steel, 

Black and Hot-Dipped, Zinc-Coated, Welded and Seamless.

173.5b. 

* * * * * * * 

ASTM A106/A106M–06a Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service.173.5b. 

* * * * * * * 

Compressed Gas Association, Inc., 

* * * * * * * 

CGA C–1, Methods for Hydrostatic Testing of Compressed Gas 

Cylinders, 2004 Edition.

180.205. 

* * * * * * * 

CGA G–2.2, Guideline Method for Determining Minimum of 0.2% 

Water in Anhydrous Ammonia, 1985, Second Edition, Reaffirmed 1997.

173.315. 


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Source and name of material 49 CFR reference 

* * * * * * * 

CGA P–20, Standard for the Classification of Toxic Gas Mixtures, 

2003, Third Edition.

173.115. 

* * * * * * * 

CGA TB–25, Design Considerations for Tube Trailers, 2005 Edition.173.301. 

* * * * * * * 

CGA V–9, Standard for Compressed Gas Cylinder Valves, 2005 

Fifth Edition.

173.40; 173.301. 

* * * * * * * 

(b) List of informational materials not 

requiring incorporation by reference. 

* * * 

Source and name of material 49 CFR reference 

* * * * * * * 

Truck Trailer Manufacturers Association, 1020 Princess Street, Alexandria, Virginia 22314 

TTMA RP No. 96–01, Structural Integrity of DOT 406, DOT 407, 

and DOT 412 Cylindrical Cargo Tanks, January, 2001 Edition.

178.345–3. 

* * * * * * * 

PART 173—SHIPPERS—GENERAL 

REQUIREMENTS FOR SHIPMENTS 

AND PACKAGINGS 

The authority citation for part 173 

continues to read as follows: 

Authority: 49 U.S.C. 5101–5128, 44701; 49 

CFR 1.45, 1.53. 

4. A new § 173.5b is added to read as 

follows: 

§ 173.5b Portable and mobile refrigeration 

systems. 

This section authorizes the highway 

transportation of residual amounts of 

Division 2.2 refrigerant gases or 

anhydrous ammonia contained in nonspecification pressure vessels that are 

components of refrigeration systems, 

which may or may not be permanently 

mounted to a transport vehicle, used for 

agricultural operations. These 

refrigeration systems are used at field 

sites to cool (pre-cool) produce before 

the produce is loaded into trucks or 

railcars for market or used to 

supplement stationary refrigeration 

systems during peak harvest times. The 

components of these refrigeration 

systems are commonly known as 

vacuum tubes, accumulators, 

refrigeration units, ice makers, pressure 

coolers, or evaporators. 

(a) General packaging requirements. 

Each non-specification pressure vessel 

must conform to the following: 

(1) Each pressure vessel must be 

designed, manufactured, and 

maintained in accordance with 

applicable requirements of the ASME 

Code (IBR, see § 171.7 of this 

subchapter). 

(2) Except as authorized in this 

section, each pressure vessel and 

associated piping must be rated at a 

maximum allowable work pressure 

(MAWP) of 250 psig. The pressure in 

these components may not exceed 

MAWP. 

(3) Any part of the piping or pressure 

vessel separated from another 

component of the refrigeration system 

by means of a valve, blank flange, or 

other device must be equipped with a 

pressure relief valve set at MAWP. All 

lines that must be disconnected for 

transportation purposes must be closed 

by means of a cap, plug or blank flange, 

and valves at the end of disconnected 

lines must be tightly closed. 

(4) The aggregate total volumetric 

capacity of components within the 

refrigeration system authorized for 

highway transportation in accordance 

with this section may not exceed 2,500 

gallons per vehicle. 

(5) Each pressure vessel and 

associated piping containing anhydrous 

ammonia must conform to the 

following: 

(i) Piping with a diameter of 2 inches 

or more must conform to ASTM 

Specification A53B Schedule 40 (IBR, 

see § 171.7 of this subchapter) or ASTM 

Specification A106 Schedule 40 (IBR, 

see § 171.7 of this subchapter). 

(ii) Piping with a diameter of less than 

2 inches must conform to ASTM 

Specification A53B (IBR, see § 171.7 of 

this subchapter) Schedule 80 or ASTM 

Specification A106 Schedule 80 (IBR, 

see § 171.7 of this subchapter). 

(iii) The words ‘‘Inhalation Hazard’’

must be marked as required in special 

provision 13 in § 172.102 of this 

subchapter and, when practicable, 

within 24 inches of the placard. 

(b) Refrigeration systems placed into 

service prior to June 1, 1991. (1) For 

refrigeration systems placed into service 

prior to June 1, 1991, each pressure 

vessel and associated piping for the 

condensing line (‘‘high side’’) must be 

rated at an MAWP of not less than 250 

psig. Each pressure vessel and 

associated piping for the evaporating 

line (‘‘low side’’) must be rated at an 

MAWP of not less than 150 psig, except 

that each pressure vessel or associated 

piping that will contain refrigerant gas 

during transportation must be rated at 

an MAWP of not less than 250 psig. 

During transportation, pressure in the 

components that are part of the 

evaporating line may not exceed 150 

psig. 

(2) Each pressure vessel and 

associated piping that is part of the 


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evaporating line must be marked ‘‘LOW 

SIDE’’ in a permanent and clearly 

visible manner. The evaporating line 

must have a pressure gauge with 

corresponding temperature markings 

mounted so as to be easily readable 

when standing on the ground. The 

gauge must be permanently marked or 

tagged ‘‘SATURATION GAUGE’’. 

(3) Each pressure vessel and 

associated piping with an MAWP of 250 

psig or greater containing liquid 

anhydrous ammonia must be isolated 

using appropriate means from piping 

and components marked ‘‘LOW SIDE’’. 

(4) Liquid lading is only authorized in 

system components with a rated MAWP 

of not less than 250 psig. 

(5) Prior to transportation, each 

pressure vessel and associated piping 

with a rated MAWP of less than 250 

psig must be relieved of enough gaseous 

lading to ensure that the MAWP is not 

exceeded at transport temperatures up 

to 54 °C (130 °F). 

(6) Refrigeration systems placed into 

service prior to June 1, 1991, may 

continue in service until October 1, 

2017. 

(c) Prior to transportation over public 

highways, each pressure vessel and 

associated piping must be drained of 

refrigerant gas or liquid anhydrous 

ammonia to the extent practicable. 

Drained contents must be recovered in 

conformance with all applicable 

environmental regulations. Residual 

liquid anhydrous ammonia in each 

component may not exceed one percent 

of the component’s total volumetric 

capacity or 10 gallons, whichever is 

less. 

(d) System inspection and testing. (1) 

Each refrigeration system authorized 

under this section must be visually 

inspected every year. The visual 

inspection must include items listed in 

§ 180.407(d)(2) applicable to 

refrigeration systems. A certificate of the 

annual visual inspection must be dated 

and signed by the person performing the 

inspection and must contain that 

person’s company affiliation. The 

certificate must remain at the equipment 

owner’s office. 

(2) Each refrigeration system 

authorized under this section must be 

proof pressure tested every two years 

beginning with the initial pressure test 

performed after manufacture. 

Additional pressure tests must be 

performed after any modification, repair 

or damage to a part of the system 

pressurized with refrigerant gas. System 

test pressures may not be less than oneand-one-half (1.50) times the rated 

MAWP of the system component or 

piping. 

(3) Pressure relief valves must be 

successfully tested every two years at 

the MAWP for the components or 

piping to which they are attached. 

Pressure relief valves may be replaced 

and marked every 5 years with valves 

certified at the appropriate MAWP, in 

which case the valves need not be tested 

every two years. Valves that do not pass 

the test must be repaired or replaced. 

(e) Test markings and reports. (1) 

Evidence of testing specified in 

paragraph (d) of this section must be 

marked on the right forward side of the 

refrigeration system with 2 inch high 

letters indicating type of last test (V = 

visual; P = pressure: hydrostatic or 

pneumatic) and the month/year in 

which it was performed. Reports and all 

of the requirements for records of 

inspections including markings must be 

completed as specified in part 180. 

(2) Pressure relief valves must be 

durably marked with either the date of 

last test, set-pressure and testing 

company or the date of last replacement, 

set-pressure, and certifying company, as 

applicable. 

5. In § 173.40, the introductory text to 

paragraph (c) is revised to read as 

follows: 

§ 173.40 General packaging requirements 

for toxic materials packaged in cylinders. 

* * * * * 

(c) Closures. When a valve is installed 

in a DOT specification cylinder 

containing a hazardous material, unless 

otherwise excepted, the valve must 

conform to the requirements in CGA V–

9 (IBR; see § 171.7 of this subchapter). 

In addition, each cylinder containing a 

Hazard Zone A material must be closed 

with a plug or valve conforming to the 

following: 

* * * * * 

6. In § 173.115, paragraph (c)(2) is 

revised to read as follows: 

§ 173.115 Class 2, Divisions 2.1, 2.2, and 

2.3—Definitions. 

* * * * * 

(c) * * * 

(2) In the absence of adequate data on 

human toxicity, is presumed to be toxic 

to humans because when tested on 

laboratory animals it has an LC50 value 

of not more than 5000 mL/m3 (see 

§ 173.116(a) of this subpart for 

assignment of Hazard Zones A, B, C or 

D). LC50 values for mixtures may be 

determined using the formula in 

§ 173.133(b)(1)(i) or CGA P–20 (IBR, see 

§ 171.7 of this subchapter). 

* * * * * 

7. In § 173.301, a new paragraph 

(a)(11) is added and paragraph (i) is 

revised to read as follows: 

§ 173.301 General requirements for 

shipment of compressed gases in cylinders 

and spherical pressure vessels. 

(a) * * * 

(11) When a valve is installed in a 

DOT specification cylinder containing a 

hazardous material, unless otherwise 

excepted, the valve must conform to the 

requirements in CGA V–9 (IBR; see 

§ 171.7 of this subchapter). 

* * * * * 

(i) Cylinders mounted in motor 

vehicles or in frames. (1) MEGCs must 

conform to the requirements in 

§ 173.312. DOT specification cylinders 

mounted on motor vehicles or in frames 

must conform to the requirements 

specified in this paragraph (i). 

(2) Seamless DOT specification 

cylinders longer than 2 m (6.5 feet) are 

authorized for transportation only when 

horizontally mounted on a motor 

vehicle or in an ISO framework or other 

framework of equivalent structural 

integrity in accordance with CGA TB–25 

(IBR, see § 171.7 of this subchapter). The 

pressure relief device must be arranged 

to discharge unobstructed to the open 

air. In addition, for Division 2.1 

(flammable gas) material, the pressure 

relief devices must be arranged to 

discharge upward to prevent any 

escaping gas from contacting personnel 

or any adjacent cylinders. 

(3) Cylinders may not be transported 

by rail in container on freight car 

(COFC) or trailer on flat car (TOFC) 

service except under conditions 

approved by the Associate 

Administrator for Safety, Federal 

Railroad Administration. 

* * * * * 

8. Section 173.338 is revised to read 

as follows: 

§ 173.338 Tungsten hexafluoride. 

(a) Tungsten hexafluoride must be 

packaged in specification 3A, 3AA, 

3BN, or 3E (§§ 178.36, 178.37, 178.39, 

178.42 of this subchapter) cylinders. 

Cylinders must be equipped with a 

valve protection cap or be packed in a 

strong outside container complying with 

the provisions of § 173.40. Outlets of 

any valves must be capped or plugged. 

As an alternative, the cylinder opening 

may be closed by the use of a metal 

plug. Specification 3E cylinders must be 

shipped in an overpack that complies 

with the provisions of § 173.40. 

(b) In place of the volumetric 

expansion test, DOT 3BN cylinders used 

in exclusive service may be given a 

complete external visual inspection in 

conformance with part 180, subpart C, 

of this subchapter, at the time such 

periodic requalification becomes due. 

Cylinders that undergo a complete 

external visual inspection, in place of 


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Federal Register / Vol. 72, No. 70 / Thursday, April 12, 2007 / Proposed Rules 18455 

the volumetric expansion test, must be 

condemned in accordance with 

§ 180.205 of this subchapter if removed 

from tungsten hexafluoride service. 

PART 176—CARRIAGE BY VESSEL 

9. The authority citation for part 176 

continues to read as follows: 

Authority: 49 U.S.C. 5101–5128; 49 CFR 

1.53. 

10. In § 176.200, paragraph (f) is 

revised to read as follows: 

§ 176.200 General stowage requirements. 

* * * * * 

(f) Class 2 (compressed gas) material 

must be kept as cool as practicable and 

be stowed away from all sources of heat 

and ignition. Any package containing a 

Division 2.1 (flammable gas) material is 

restricted from transport in powered 

refrigerated temperature controlled 

containers, unless the equipment is 

capable of preventing ignition of 

flammable vapors by having nonsparking or explosion-proof electric 

fittings within the cooling compartment. 

PART 178—SPECIFICATIONS FOR 

PACKAGINGS 

11. The authority citation for part 178 

continues to read as follows: 

Authority: 49 U.S.C. 5101–5128; 49 CFR 

1.53. 

12. In § 178.68, paragraph (l)(2) is 

revised to read as follows: 

§ 178.68 Specification 4E welded 

aluminum cylinders. 

* * * * * 

(l) * * * 

(2) Guided bend test. A bend test 

specimen must be cut from the cylinder 

used for the physical test specified in 

paragraph (j) of this section. Specimen 

must be taken across the seam, must be 

a minimum of 11⁄2 inches wide, edges 

must be parallel and rounded with a 

file, and back-up strip, if used, must be 

removed by machining. The specimen 

shall be tested as follows: 

(i) The specimen must be bent to 

refusal in the guided bend test jig as 

illustrated in paragraph 6.10 of CGA C–

3 (IBR, see § 171.7 of this subchapter). 

The root of the weld (inside surface of 

the cylinder) must be located away from 

the ram of the jig. The specimen must 

not show a crack or other open defect 

exceeding 1⁄8 inch in any direction upon 

completion of the test. Should this 

specimen fail to meet the requirements, 

specimens may be taken from each of 2 

additional cylinders from the same lot 

and tested. If either of the latter 

specimens fails to meet requirements, 

the entire lot represented must be 

rejected. 

(ii) Alternatively, the specimen may 

be tested in a guided bend test jig as 

illustrated in paragraph 12 of The 

Aluminum Association’s publication, 

‘‘Welding Aluminum: Theory and 

Practice’’ (IBR, see § 171.7 of this 

subchapter). The root of the weld 

(inside surface of the cylinder) must be 

located away from the mandrel of the 

jig. No specimen must show a crack or 

other open defect exceeding 1⁄8 inch in 

any direction upon completion of the 

test. Should this specimen fail to meet 

the requirements, specimens may be 

taken from each of 2 additional 

cylinders from the same lot and tested. 

If either of the latter specimens fails to 

meet requirements, the entire lot 

represented must be rejected. 

* * * * * 

13. In § 178.345–3, at the end of 

paragraph (a)(3), a sentence is added to 

read as follows: 

§ 178.345–3 Structural integrity. 

(a) * * * 

(3) * * * TTMA RP 96–01, Structural 

Integrity of DOT 406, DOT 407, and 

DOT 412 Cylindrical Cargo Tanks, may 

be used as guidance in performing the 

calculations. 

* * * * * 

14. In § 178.345–5, paragraph (f) is 

revised to read as follows: 

§ 178.345–5 Manhole assemblies. 

* * * * * 

(f) All components mounted on a 

manhole cover that form part of the 

lading retention structure of the cargo 

tank wall must withstand the same 

static internal fluid pressure as that 

required for the manhole cover. The 

component manufacturer shall verify 

compliance using the same test 

procedure and frequency of testing as 

specified in § 178.345–5(b). 

PART 180—CONTINUING 

QUALIFICATION AND MAINTENANCE 

OF PACKAGINGS 

15. The authority citation for part 180 

continues to read as follows: 

Authority: 49 U.S.C. 5101–5128; 49 CFR 

1.53. 

16. In § 180.205, paragraph (g) is 

revised to read as follows: 

§ 180.205 General requirements for 

requalification of specification cylinders. 

* * * * * 

(g) Pressure test. Unless otherwise 

provided, each cylinder required to be 

pressure tested under this subpart must 

be tested by means suitable for 

measuring the expansion of the cylinder 

under pressure. The pressure test 

procedures and equipment accuracy for 

the volumetric expansion test and, 

when authorized, the proof pressure test 

must be in accordance with CGA C–1 

(IBR, see § 171.7 of this subchapter), 

subject to the following limitations as 

applicable: 

(1) Bands and other removable 

attachments must be loosened or 

removed before testing so that the 

cylinder is free to expand in all 

directions. 

(2) Each day before testing, the 

requalifier shall confirm the accuracy of 

the expansion-indicating device and the 

pressure-indicating device by using a 

calibrated cylinder or other method 

authorized in writing by the Associate 

Administrator. In the event the 

calibrated cylinder’s expansion values 

have changed from the certified 

certificate expansion values, the 

calibrated cylinder may be recalibrated 

using a dead weight test device 

traceable to the National Institute of 

Standards and Testing (NIST) 

measurement standards or using another 

calibrated cylinder. 

(3) The requalifier must demonstrate 

calibration in conformance with this 

paragraph (g) to an authorized inspector 

on any day that the requalifier retests 

cylinders. A requalifier must maintain 

calibrated cylinder certificates in 

accordance with § 180.215(b)(4). 

(4) When a test pressure cannot be 

achieved or maintained due to a 

malfunction of the test equipment, the 

pressure test may be repeated only at a 

pressure increased by 10% or 100 psig, 

whichever is the lower value. The 

cumulative increase in test pressure 

may not exceed 10% of minimum 

prescribed test pressure. 

(5) This paragraph (g) does not 

authorize retest of a cylinder otherwise 

required to be condemned under 

paragraph (i) of this section. 

* * * * * 

In § 180.407, paragraphs (d)(3) and 

(g)(1)(ii)(A) are revised to read as 

follows: 

§ 180.407 Requirements for test and 

inspection of specification cargo tanks. 

* * * * * 

(d) * * * 

(3) All reclosing pressure relief valves 

must be externally inspected for any 

corrosion or damage which might 

prevent safe operation. All reclosing 

pressure relief valves on cargo tanks 

carrying lading corrosive to the valve 

must be removed from the cargo tank for 

inspection and testing. Each reclosing 

pressure relief valve required to be 

removed and tested must open at no less 

than the required set pressure and no 


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18456 Federal Register / Vol. 72, No. 70 / Thursday, April 12, 2007 / Proposed Rules 

more than 110 percent of the required 

set pressure and reseat to a leak-tight 

condition at 90 percent of the set-todischarge pressure or the pressure 

prescribed for the applicable cargo tank 

specification. 

* * * * * 

(g) * * * 

(1) * * * 

(ii) * * * 

(A) Each self-closing pressure relief 

valve that is an emergency relief vent 

must open at no less than the required 

set pressure and no more than 110 

percent of the required set pressure and 

reseat to a leak-tight condition at 90 

percent of the set-to-discharge pressure 

or the pressure prescribed for the 

applicable cargo tank specification. 

* * * * * 

Issued in Washington, DC on April 6, 2007 

under authority delegated in 49 CFR part 

106. 

Theodore L. Willke, 

Acting Associate Administrator for 

Hazardous Materials Safety. 

[FR Doc. E7–6942 Filed 4–11–07; 8:45 am] 

BILLING CODE 4910–60–P 


rmajette on PROD1PC67 with PROPOSALS