Federal Motor Vehicle Safety Standards; Brake Hoses, 57459-57473 [E7-19474]

Agencies

• National Highway Traffic Safety Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 72, Number 194 (Tuesday, October 9, 2007)]
[Proposed Rules]
[Pages 57459-57473]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-19474]



Federal Register / Vol. 72, No. 194 / Tuesday, October 9, 2007 / 
Proposed Rules

[[Page 57459]]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2007-29348]
RIN 2127-AK01


Federal Motor Vehicle Safety Standards; Brake Hoses

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document, together with a companion final rule; technical 
amendments; response to petitions; published in today's edition of the 
Federal Register, addresses issues raised in petitions received in 
response to a December 2004 final rule that updated the Federal motor 
vehicle safety standard on brake hoses, and a related petition for 
rulemaking. In that rule, we incorporated updated versions of 
substantive specifications of several Society of Automotive Engineers 
(SAE) Recommended Practices relating to hydraulic brake hoses, vacuum 
brake hoses, air brake hoses, plastic air brake tubing, and end 
fittings.
    In this NPRM, we respond to some issues raised in the petitions and 
propose a number of amendments to the brake hose rule in response to 
the petitions.
    In the companion document, we deny several of the petitions and 
also correct typographical errors in, and inadvertent omissions from, 
the December 20, 2004 final rule.

DATES: Comments must be received on or before December 10, 2007.

ADDRESSES: Comments should refer to the docket number above and be 
submitted to:
     Mail: Docket Management Facility, M-30, U.S. Department of 
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: Documents may be submitted by hand delivery 
or courier to: Docket Management Facility, West Building, Ground Floor, 
Rm. W12-140, 1200 New Jersey Avenue, SE., Washington, DC between 9 a.m. 
and 5 p.m., except for Federal holidays.
     Fax: Faxed submissions are accepted at: 202-493-2251.
     Online: Alternatively, you may submit your comments 
electronically by logging onto the Federal Docket Management System 
(FDMS) Web site at https://www.regulations.gov. Follow the online 
instructions for submitting comments.
    Regardless of how you submit your comments, you should mention the 
docket number of this document.
    You may call the Docket at 202-366-9324. Docket hours are 9 a.m. to 
5 p.m., Monday through Friday, except for Federal holidays.
    Please see the Privacy Act heading under Rulemaking Analyses and 
Notices.

FOR FURTHER INFORMATION CONTACT:
    For non-legal issues, Mr. Jeff Woods, Vehicle Dynamics Division, 
Office of Vehicle Safety Standards (Telephone: 202-366-6206) (Fax: 202-
366-4921). Mr. Woods' mailing address is National Highway Traffic 
Safety Administration, NVS-122, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.
    For legal issues, Ms. Dorothy Nakama, Office of the Chief Counsel 
(Telephone: 202-366-2992) (Fax: 202-366-3820). Ms. Nakama's mailing 
address is National Highway Traffic Safety Administration, NCC-112, 
1200 New Jersey Avenue, SE., Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background
II. December 20, 2004 Final Rule
III. Petitions
IV. Proposed Revisions to FMVSS No. 106
    A. Hydraulic Brake Hoses
    1. Compatibility Fluid
    B. Air Brake Hoses
    1. Overview of Petitions
    2. Air Brake Hose Dimensions
    3. Type AIII Dimensions for Air Brake Hose- Gates Petition
    4. Metric Sizes of Air Brake Hoses
    5. High Temperature Resistance
    C. Vacuum Brake Hoses
    1. Overview of Petitions
    2. High Temperature Resistance
    3. Deformation
    4. Table V
    D. Plastic Air Brake Tubing
    1. Overview of Petitions
    2. Plastic Air Brake Tubing Dimensions
    3. Notations to Table VII
    4. Plastic Air Brake Tubing Mechanical Properties
    5. Impact Test Apparatus
    6. Resistance to Corrosive Salt Compounds
    7. Resistance to Methyl Alcohol
V. Rulemaking Analyses and Notices
    A. Executive Order 12866 and DOT Regulatory Policies and 
Procedures
    B. Regulatory Flexibility Act
    C. National Environmental Policy Act
    D. Executive Order 13132 (Federalism)
    E. Civil Justice Reform
    F. Paperwork Reduction Act
    G. National Technology Transfer and Advancement Act
    H. Unfunded Mandates Reform Act
    I. Plain Language
    J. Regulation Identifier Number
    K. Privacy Act
    L. Comments

I. Background

    On October 30, 1998, a joint petition for rulemaking was filed by 
Elf Atochem North America, Inc., Mark IV Industrial/Dayco Eastman, and 
Parker Hannifin Corporation, three brake hose manufacturers. The 
petitioners petitioned for certain requirements relating to brake 
hoses, brake hose tubing, and brake hose end fittings administered by 
the Federal Motor Carrier Safety Administration (FMCSA) to be 
incorporated into the brake hose standard that is currently 
administered by the National Highway Traffic Safety Administration 
(``NHTSA'' or the ``agency''). Specifically, the petitioners sought 
incorporation of the requirements in section 393.45 (Brake tubing and 
hose, adequacy) and section 393.46 (Brake tubing and hose connections) 
of the Federal Motor Carrier Safety Regulations (FMCSR) into section 
571.106 (Brake hoses) of the Federal motor vehicle safety standards 
(``FMVSS''). The petition requested that the application of these SAE 
specifications be limited to hose, tubing, and fittings used on trucks, 
truck-trailer combinations, and buses with either a GVWR greater than 
10,000 lbs. or which are designed to transport 16 or more people, 
including the driver. In addition, the petitioners requested that the 
current versions of the SAE specifications be adopted instead of the 
older versions cited in the FMCSRs.
    NHTSA granted the joint petition for rulemaking, and published a 
notice of proposed rulemaking on May 15, 2003 (68 FR 26384, DOT Docket 
No. 03-14483). The agency agreed with the petitioners that there was a 
safety need to transfer the brake hose, tubing, and fitting 
requirements currently contained in sections 393.45 and 393.46 of the 
FMCSRs to FMVSS No. 106, before those requirements are deleted. NHTSA 
tentatively concluded that to ensure the continued safety of commercial 
motor vehicle braking systems, the substantive specifications of the 
SAE Recommended Practices should be incorporated into FMVSS No. 106, 
with a few exceptions as noted. This would involve, among other 
changes, establishing a new category in the standard for plastic air 
brake tubing, end fittings, and tubing assemblies.
    NHTSA's decision to grant the joint petition was also based on the 
fact that FMVSS No. 106 has not been substantially updated in many 
years. Revisions over the past 20 years primarily addressed labeling 
issues,

[[Page 57460]]

inclusion of metric-sized brake hoses, updating test fluids to match 
advances in industry, and minor regulatory revisions to individual test 
conditions such as the whip test and the adhesion test. We noted that 
most of the substantive requirements in Standard 106, other than the 
labeling requirements, were originally based on SAE standards and 
American Society for Testing and Materials (ASTM) standards referenced 
therein. While the SAE and ASTM standards have been modified over time 
to keep pace with technological developments in the industry, the 
substantive requirements of FMVSS No. 106 have remained relatively 
unchanged. NHTSA's proposed changes to Standard No. 106 would take into 
account the substantial technological developments that have occurred 
and align the standard's requirements with standard industry practices. 
Incorporating many of the SAE standard's performance requirements is 
consistent with Office of Management and Budget (OMB) Circular A-119, 
which directs federal agencies to use and/or develop voluntary 
consensus industry standards, in accordance with Public Law 104-113, 
the ``National Technology Transfer and Advancement Act of 1995.''

II. December 2004 Final Rule

    On December 20, 2004 (69 FR 76298, DOT Docket No. NHTSA-2003-
14483), NHTSA published a final rule amending the brake hose standard. 
The agency's rule differed in the following respects from that 
petitioned for by the petitioners--
    First, instead of simply incorporating complete SAE standards by 
reference as the FMCSRs currently do, NHTSA incorporated only the 
specific requirements/specifications of the SAE standards that are 
either more rigorous than those in Standard No. 106 or are not present 
at all in FMVSS No. 106.
    Second, the agency did not limit the application of those SAE 
requirements/specifications to brake hose, tubing, and fittings used on 
commercial motor vehicles. NHTSA determined that all brake hose, 
tubing, and fittings can and should meet the requirements/
specifications, regardless of their end use.
    Third, although NHTSA agreed with the petitioners that changes to 
FMVSS No. 106 should be based on the most recent versions of the SAE 
standards, instead of the older versions cited in the FMCSRs, the 
agency noted that a number of SAE's standards have been updated since 
the joint petition was filed (in 1998). Accordingly, NHTSA relied on 
what it believed to be the most recent versions of the SAE standards.
    Fourth, the agency did not incorporate SAE standards relating to 
copper tubing, galvanized steel pipe, or end fittings used with 
metallic or non-metallic tubing, materials that are occasionally used 
in chassis plumbing. Since these products are not considered to be 
brake hoses, NHTSA determined them not to be appropriate to include in 
FMVSS No. 106, a brake hose standard.
    Fifth, NHTSA did not incorporate the material and construction 
specifications for Type A and Type B tubing contained in SAE J844, 
Nonmetallic Air Brake System Tubing, and SAE J1394, Metric Nonmetallic 
Air Brake System Tubing because the agency tentatively concluded that 
incorporating those material specifications would be design-
restrictive.
    Sixth, NHTSA did not incorporate the manufacturer identification 
requirements in SAE J1401, Hydraulic Brake Hose Assemblies for Use with 
Nonpetroleum-Base Hydraulic Fluids, because it concluded that the 
manufacturer identification requirements already present in FMVSS No. 
106 are sufficient.

III. Petitions

    In early 2005, NHTSA received petitions for reconsideration of the 
December 20, 2004 final rule from Cooper Standard Automotive (Fluid 
Division), Degussa Corporation, George Apgar Consulting, MPC, Inc., and 
Parker Hannifin Corporation (with separate comments from its Brass 
Division and from its Hose Products Division). In July 2005, Arkema, 
Inc., submitted a document styled as a petition for reconsideration. 
NHTSA is treating the document as a petition for rulemaking instead 
since its regulations (49 CFR 553.35(a)) provide that a document styled 
as a petition for reconsideration of a final rule and received by the 
agency more than 45 days after the issuance of that final rule will be 
treated as a petition for rulemaking. The petitions addressed a wide 
range of FMVSS No. 106 subjects.
    We are addressing a number of the petitions by proposing amendments 
to FMVSS No. 106 in this NPRM. In a companion document published in 
today's edition of the Federal Register, we are addressing other issues 
raised in the petitions and in some instances, are denying the 
petitions. In some cases, in this NPRM, we are proposing changes based 
on suggestions or petitions, but which deviate from the requested 
changes. Thus, several petitions are partially granted in this respect.

IV. Proposed Revisions to FMVSS No. 106

A. Hydraulic Brake Hoses

    1. Compatibility Fluid--In the final rule, the agency adopted a 
revised SAE compatibility brake fluid, RM-66-04, incorporated by 
reference in FMVSS No. 106, S5.3.9, Brake Fluid Compatibility, 
Constriction, and Burst Strength test requirements. Since the 
publication of the December 2004 final rule, we have discovered that 
SAE J1703 was revised in April 2004. Appendix B of SAE J1703 (April 
2004) references a new compatibility brake fluid, RM-66-05. In this 
NPRM, we propose to incorporate the reference to the current version of 
SAE compatibility brake fluid, RM-66-05.
    We have checked the SAE Web site (https://www.sae.org) for 
information on the availability of the RM-66-05 compatibility brake 
fluid, since we have been made aware by SAE that it would no longer be 
selling this referee material. However, as indicated on the SAE 
website, the compatibility brake fluid is now available for purchase 
from Greening Associates, Inc. in Detroit, Michigan. As long as SAE 
continues to identify the supplier of the compatibility brake fluid, 
NHTSA sees no need to provide this information in FMVSS No. 106. 
Therefore, we are not proposing to identify the supplier in this 
notice. We welcome comments on this issue.

B. Air Brake Hoses

    1. Overview of Petitions--In response to the agency's final rule, 
there was one petition received on air brake hose from Parker Hannifin, 
Hose Products Division. Parker provided suggestions for changes to the 
construction and labeling information provided in Table III of FMVSS 
No. 106. Parker also petitioned for changes to the high temperature 
resistance test for air brake hose. We also address a petition for 
rulemaking from Gates Corporation that requests adding Type AIII air 
brake hose to Table III. All these issues are discussed in further 
detail below.
    2. Air Brake Hose Dimensions--Parker stated in its petition that 
the footnotes for Table III in FMVSS No. 106 should indicate that all 
types of air brake hose (Type A, AI, and AII) can be used with either 
reusable or permanently attached end fittings, and that fittings types 
are not interchangeable with hose types due to differences in outside 
diameters of Type A, AI, and AII hose. In addition, in this NPRM, we 
address a petition for rulemaking from Gates Corporation that asks that 
we add Type AIII air brake hose to Table III. Gates also petitioned

[[Page 57461]]

for a change in the applicability so that Table III applies only to air 
brake hoses for use with reusable end fittings. As is addressed in more 
detail below, in response to the Gates petition, we propose that Table 
III be revised so that it applies to air brake hoses only for use with 
reusable end fittings, meaning that there would no longer be a need for 
the table's footnotes. Therefore, in this notice we are not proposing 
any changes to the footnotes as requested by Parker. Instead, we are 
proposing to remove all of the footnotes from Table III.
    3. Type AIII Dimensions for Air Brake Hose--Gates' Petition for 
Rulemaking--In a submission dated November 22, 2005, Gates Corporation 
(Gates) petitioned NHTSA to amend the December 20, 2004 version of 
FMVSS No. 106. In particular, Gates asked us to amend S7.1 Construction 
for the following reason:

    The revised wording now places dimensional limits, that were not 
present in the previous version, on hoses manufactured for use with 
permanently attached brake hose end fittings only. Gates Corporation 
manufactures such hoses and this new ruling would exclude Gates 
Corporation from providing air brake assemblies which it currently 
supplies under FMVSS 106. These current air brake assemblies meet 
all the performance requirements of the current version of FMVSS 106 
and will continue to meet the performance requirements set forth in 
the above listed final ruling [referring to FMVSS No. 106 in the 
October 1, 2000 edition of Title 49 of the Code of Federal 
Regulations, Parts 400 to 599].

    Gates petitioned to amend FMVSS No. 106 as follows: First, to amend 
S7.1, Construction, by reverting to the regulatory text that exists now 
(before the December 20, 2004 final rule text takes effect) so that 
Table III, that specifies dimensional requirements for air brake hoses, 
only applies to air brake hoses that are assembled with reusable end 
fittings. Second, Gates asked that the statement ``except for brake 
hose manufactured in metric sizes'' (having the effect that metric 
sizes of brake hose for use with reusable fittings could be sold 
without meeting any dimensional requirements specified in FMVSS No. 
106) be added.
    Third, Gates petitioned to add Type AIII dimensions for air brake 
hose to Table III in FMVSS No. 106. Table III already includes 
dimensions for Type A, Type AI, and Type AII air brake hoses. According 
to its petition, Gates manufactures Type AIII, an air brake hose used 
only with permanently attached end fittings.
    The agency has reviewed Gates' petition and has decided to grant it 
for the following reasons. We have determined that amending S7.1 in the 
way Gates has petitioned for would mean, as was the case prior to the 
agency's December 20, 2004 final rule, that the Table III designations 
would apply only to air brake hoses that are assembled with reusable 
end fittings. Although Gates did not indicate why it wants Type AIII 
added to Table III when Gates has no stated intention of using this 
hose with reusable end fittings, the agency believes that adding the 
Type AIII designation would not be problematic or adversely affect 
safety.
    The agency believes that it may not be as critical to specify 
dimensions for air brake hoses that are only assembled with permanently 
attached end fittings, because specialized equipment is needed to 
produce such brake hose assemblies. Many of the assemblers doing this 
work on a repair basis (as evidenced by the agency's listing of 
registered brake hose assemblers) are small businesses that purchase or 
use a complete system of compatible end fittings, brake hoses, and 
crimping or swaging equipment for a particular brand of brake hoses. 
Thus the agency believes that it is not likely for an assembler with 
specialized knowledge and equipment to mix improper components when 
assembling air brake hoses with permanently attached end fittings, 
compared to a person making field repairs to an air brake hose with 
reusable end fittings that do not require specialized equipment to 
disassemble and reassemble the end fittings.
    4. Metric Sizes of Air Brake Hoses--In the final rule of December 
20, 2004, Table III specifies hose sizes only in English units of 
measurement (i.e., \3/16\ inch, \1/4\ inch, \5/16\ inch). In contrast, 
metric measurements are metric units expressed in whole millimeters 
such as 5 millimeters or 8 millimeters.\1\ In the December 20, 2004 
final rule, at page 76,303, NHTSA addressed the issue of specifying 
metric measurements for air brake hoses:

    \1\ NHTSA does not consider the inside diameter and outside 
diameter conversions of English units into metric measurements 
(resulting in numbers such as 5.8 millimeters or 16.7 millimeters) 
to be ``metric-sized air brake hose.''

    Regarding metric sizes of air brake hose, in the NPRM, NHTSA 
noted that dimensions for metric air brake hoses are not included in 
FMVSS No. 106, and solicited comments on the dimensions for metric 
air brake hose (for use with permanently attached, or reusable end 
fittings) that may be appropriate to include in FMVSS No. 106. Since 
it received no comments on this subject, NHTSA will not include 
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metric air brake hoses in Table III.

    In order to assure standardization and compatibility of the hose 
and end fittings and to ensure the safety of replacement brake hoses 
used with existing end fittings, in this NPRM, the agency proposes, for 
air brake hoses in metric measurements, to permit air brake hoses with 
permanently attached end fittings only. Therefore, the agency does not 
propose to change the regulatory text in S7.1 as requested by Gates to 
exclude metric brake hoses for use with reusable end fittings from 
having dimensional requirements specified in Table III. Metric air 
brake hoses would still be permitted to be assembled and sold with 
permanently attached end fittings under this proposal. This issue is 
ambiguous under the regulatory text of the December 20, 2004 final rule 
because metric air brake hoses are referred to in the labeling 
requirements of S7.2 (without specifying whether the metric air brake 
hoses are those with permanently-attached or reusable end fittings), 
while every air brake hose was required to meet the dimensional 
requirements in Table III and no ``metric measurement'' sizes were 
included in that table.
    This NPRM seeks to resolve the ambiguity by proposing to specify 
metric air brake hose for use only with permanently attached end 
fittings. As explained above, we believe that it may not be as critical 
to specify dimensions for air brake hoses that are only assembled with 
permanently-attached end fittings, because specialized equipment is 
needed to produce such brake hose assemblies. Therefore, before a 
manufacturer may manufacture or sell new metric air brake hose for use 
with reusable end fittings, the metric hose dimensions must first be 
added to Table III in FMVSS No. 106 through the agency's rulemaking 
process.
    We agree that it would be appropriate to propose adding Type AIII 
air brake hoses to Table III in FMVSS No. 106 as requested by Gates. In 
its petition, Gates stated that it had initiated a project with the SAE 
to have Type AIII air brake hose added to the dimensional tables in 
recommended practice SAE J1402, Automotive Air Brake Hose and Hose 
Assemblies. However, since amended SAE J1402 has not yet been issued by 
the SAE, NHTSA has decided not to wait for issuance of an amended 
J1402, and then propose to incorporate by reference the amended J1402 
into FMVSS No. 106. In this NPRM, we propose to include in FMVSS No. 
106, the Type AIII air brake hose dimensions from the draft J1402 
document.
    By proposing to include the Type AIII designation for brake hose in 
Table III, NHTSA is not proposing to require that the hoses be 
assembled with reusable fittings. However, to meet Gates' petition for 
their hose designation to be

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added to FMVSS No. 106, S7.1 would need additional language so that if 
a hose is manufactured to the specifications in Table III it must be 
labeled as such. The agency is proposing that language in this notice 
at S7.2.1(e).
    We also reviewed the footnotes of various revisions of J1402 and 
found that while Type AI and AII hoses could be installed with either 
permanently attached end fittings or reusable end fittings, only three 
sizes of Type A hose (\3/8\ inch, \7/16\ inch, and \1/2\ SP 
(``special'') inch) are designated in J1402 for use with reusable end 
fittings, and the remaining three sizes (\1/4\ inch, \5/16\ inch, and 
\5/8\ inch) are designated for use with permanently attached end 
fittings only. NHTSA's proposal, if made final, would eliminate the 
need for footnotes, since various types of hoses can be included in 
Table III regardless of whether they are used with reusable or 
permanently attached end fittings.
    We therefore propose to remove all footnotes to Table III. These 
footnotes were added in the December 20, 2004 brake hose final rule to 
identify brake hoses that can be used with reusable and/or permanently 
attached end fittings. With the proposed revision of S7.1 and 
S7.2.1(e), the footnotes would no longer serve any purpose. In 
addition, NHTSA proposes that any one of the designations of brake 
hoses proposed for Table III, as well as hose types that are not listed 
in Table III, be permitted to be assembled with permanently-attached 
end fittings.
    Public comment is sought on whether the proposed Type AIII 
designated hoses should be applicable both to hoses with permanently-
attached end fittings and to hoses with reusable end fittings.
    5. High Temperature Resistance--In its rulemaking to update FMVSS 
No. 106, the agency adopted the substantive requirements of SAE J1402, 
Automotive Air Brake Hose and Hose Assemblies, June 1985, into FMVSS 
No. 106. Revisions in the final rule included modification of the FMVSS 
No. 106 requirements in S7.3.2, High temperature resistance test, in 
which an air brake hose is secured around a test cylinder and 
conditioned at 100 degrees Celsius (212 degrees Fahrenheit) for 70 
hours. After this conditioning, the hose is cooled and examined on the 
inside and outside for cracks, charring, or disintegration. In the 
final rule, the test cylinder specification was revised to include 
smaller test cylinders for each size of air brake hose that are 
specified in SAE J1402 (June 1985).
    Parker's comment submitted in response to the final rule stated 
that SAE J1402 was in the process of being revised to change the 
dimensions of the test cylinders for the high temperature resistance 
test, and requested that the agency now consider adopting the new sizes 
of test cylinders in FMVSS No. 106. The agency has reviewed the revised 
standard, SAE J1402, Automotive Air Brake Hose and Hose Assemblies 
(January 2005), and finds that it includes revisions to the test 
cylinders for the high temperature test. The sizes of the high 
temperature test cylinders were increased to be the same size as the 
test cylinders used for other tests in SAE J1402, including the low 
temperature resistance test, ozone resistance test, and the adhesion 
test for air brake hose reinforced by wire.
    The agency proposes that the latest requirements for the size of 
the test cylinders for the high temperature test as stated in SAE J1402 
(January 2005) be adopted in FMVSS No. 106 as well. The stringency of 
the high temperature resistance test would be reduced slightly, due to 
larger test cylinders being used, but this would also result in only 
one size of test cylinders being needed for all of the test 
requirements for air brake hose in FMVSS No. 106 where the use of test 
cylinders is required, and in addition, FMVSS No. 106 would be aligned 
with the latest revision of SAE J1402. The net effect of this proposed 
change is that the test cylinder dimensions for the high temperature 
resistance test would be changed back to their original values (prior 
to the agency's extensive recent rulemaking on brake hoses) that were 
in effect for many years.

C. Vacuum Brake Hose

    1. Overview of Petitions--In the May 15, 2003 NPRM to amend FMVSS 
No. 106, the agency indicated that it was aware that plastic vacuum 
brake tubing is being used in automotive applications as an alternative 
material to rubber vacuum brake hose (68 FR 26397). The agency stated 
that it was not aware of SAE or other industry standards for plastic 
vacuum tubing, but that if a suitable industry standard were developed, 
we would consider adopting performance requirements from that standard 
into FMVSS No. 106. In response to the final rule, Degussa, Cooper, and 
MPC have petitioned for changes to the requirements in FMVSS No. 106 
for vacuum brake hose constructed of plastic. The requirements in FMVSS 
No. 106 at issue are S9.2.2, High temperature resistance, and S9.2.9, 
Deformation.
    Degussa stated that there are no industry standards for plastic 
vacuum brake tubing and believes that it is not feasible to create a 
complete separate set of requirements for plastic vacuum brake tubing 
within FMVSS No. 106. However, it and other petitioners submitted two 
proposed changes specific to plastic vacuum brake tubing that could be 
incorporated within the S9 and S10 requirements for vacuum brake tubing 
in FMVSS No. 106.
    MPC, Degussa, and Cooper provided the view that plastic vacuum 
brake tubing has advantages over rubber vacuum brake hose in certain 
automotive applications, including recyclability, smaller packaging 
size, lighter weight, improved abrasion and leak resistance, and ease 
of assembly. Cooper stated that the majority of European automakers 
that import motor vehicles into the United States use plastic vacuum 
brake tubing, and that this product has been used in Europe for more 
than a decade.
    MPC stated that it could not locate Table V or Table VI in the 
final rule or in the agency's compliance test procedure. The agency 
notes that since these tables were not revised in the brake hose 
rulemaking, they did not appear in the final rule, but they are 
included in FMVSS No. 106 (49 CFR 571.106). However, as discussed 
below, the agency is now considering revisions to Table V and the 
proposed revisions to the table are included in this notice.
    2. High Temperature Resistance--The requirements in S9.2.2 and 
S10.1 of FMVSS No. 106 include conditioning the hose at an elevated 
temperature of 257 degrees Fahrenheit (125 degrees Celsius) under an 
internal vacuum of 26 inches of mercury for 96 hours. Upon completion 
of that conditioning, the collapse of the outside diameter shall not 
exceed 10 percent for a heavy-duty vacuum brake hose or 15 percent for 
a light duty vacuum brake hose. Next, the hose is cooled to room 
temperature and bent around a mandrel with a diameter equal to five 
times the initial outside diameter of the hose. Upon inspection, while 
still bent around the mandrel, the hose must not exhibit any 
indications of cracks, charring, or disintegration. Finally, the hose 
is removed from the mandrel and subjected to a 175 psi hydrostatic 
burst test for one minute with no leakage permitted.
    MPC stated that plastic tubing is more rigid than rubber hose and 
they have a concern that the tubing may kink when bent around the 
mandrel. The kinking can cause stress marks on the outside of the 
tubing, and although these marks are not associated with mechanical 
failure of the tubing, the marks could be interpreted as cracks 
resulting in failure of the test. MPC states that a typical 12.7 mm 
outside diameter tube will kink at

[[Page 57463]]

mandrel diameters below 100 mm (or approximately 8 times the outside 
diameter of the tube). MPC recommends that the mandrel size be 
increased to a diameter in excess of 8 times the outside diameter of 
the plastic tube.
    The agency agrees that vacuum tubing manufactured from plastic 
typically is less flexible than a vacuum hose constructed of rubber and 
therefore a larger mandrel should be considered for this test 
requirement. The agency is proposing that the mandrel diameter be 
changed to eight times the outside diameter of the tubing if the tubing 
is constructed of plastic.
    3. Deformation--The vacuum brake hose deformation requirements are 
specified in S9.2.10 of FMVSS No. 106, and the deformation test 
procedure is specified in S10.9. In this performance test, a one-inch 
long sample of vacuum brake hose is compressed so that the inside 
diameter is flattened to a specified value, and then the compressive 
force is released. This is repeated four more times, and upon 
completion of the compression test sequence the inside diameter of the 
vacuum brake hose shall be at least 90 percent of its original inside 
diameter, or, in the case of a vacuum brake hose reinforced with wire, 
it shall return to at least 85 percent of its original diameter. The 
compressive force application for a heavy-duty vacuum brake hose shall 
not exceed 70 pounds in the first compressive cycle, and shall be at 
least 40 pounds in the fifth compressive cycle. The compressive force 
application for a light-duty vacuum brake hose shall not exceed 50 
pounds in the first compressive cycle, and shall be at least 20 pounds 
in the fifth compressive cycle.
    In summary, this performance test requires that the hose has at 
least a minimum amount of flexibility (specified through an upper limit 
of compressive force application) and shape recovery so it returns 
nearly to its original shape after several applications of compressive 
force.
    Degussa stated that the deformation requirements as currently 
included in FMVSS No. 106 would, in effect, prohibit the use of plastic 
tubing. It stated that the high shape recovery requirements and low 
compression force are typical for elastomers but that plastics are 
typically stronger and cannot meet these requirements. Degussa 
recommended either removing these requirements from FMVSS No. 106, or 
changing the post-compression recovery criteria to 60 percent of 
original outside diameter with a first compression force of less than 
500 pounds.
    Cooper cited similar reasons to exclude plastic tubing from the 
deformation requirements or to adopt an alternative requirement of a 
post-compression recovery of 60 percent of original outside diameter 
with a first compressive application force of no more than 500 pounds. 
Cooper stated that plastic tubing is constructed of a stronger material 
than that of elastomeric hose and that the stronger plastic tubing does 
not deform as easily under the low compressive forces in the 
deformation test.
    MPC stated similar concerns. It stated that the thermoplastic tubes 
will not compress with loads as low as 70 pounds and will not have the 
shape recovery of an elastomeric hose, and that it would take a 
significantly higher amount of force to compress the plastic tubing. 
MPC recommended that the deformation test be eliminated for plastic 
tubing, or as an alternative, that if no deformation occurs at a 
compressive force of 70 pounds for a sample of tubing one inch in 
length, then the tubing would meet the deformation requirement.
    The agency agrees that plastic vacuum brake tubing has properties 
that are substantially different than those of an elastomeric (rubber) 
vacuum brake hose. Principal among these differences is the increased 
stiffness of the plastic tubing that would not result in substantial 
collapse upon application of compressive forces in the 20 to 70-pound 
range for a test sample that is one inch in length (the specified 
sample length for all diameters of brake hose in Table VI).
    After consideration of the suggested alternatives for plastic 
vacuum brake hose, the agency has decided to propose that a compressive 
force of 70 pounds be applied to the hose for five cycles, and that the 
recovery shall be at least 90 percent of the original outside diameter. 
This approach keeps the test parameters within the original 
specifications of the deformation test, and recognizes the increased 
mechanical strength of the plastic hose.
    The agency also proposes to modify Table V to accommodate the 
proposed deformation test. The agency proposes to remove the ninth 
column of Table V that specifies the collapsed hose inside dimension 
for the deformation test, because these dimensions are redundant with 
the same dimensions in column six of Table VI. The agency prefers to 
have these specifications included in only one table where it is most 
relevant, which the agency proposes to be Table VI.
    4. Table V--In addition, the agency notes that Table V--Vacuum 
Brake Hose Test Requirements, was not revised in the recent brake hose 
rulemaking to be consistent with the high temperature resistance 
requirements in the final rule. The third and fourth columns of the 
table indicate hose test sample length and test cylinder radius, 
respectively, for the high temperature resistance test. However, since 
the test cylinder radius or diameter was changed to a specification as 
a multiple of the vacuum brake hose initial outside diameter (five 
times the outside diameter of the brake hose), column four of Table V 
should be deleted.
    The agency also notes that the length of the test sample of brake 
hose in column three of Table V deviates from SAE J1403 Vacuum Brake 
Hose (July 1989) which indicates that a 300 mm (11.8 inch) length of 
vacuum brake hose is used in this test. Therefore, the agency proposes 
to revise S10.1 to specify the length of the brake hose test sample as 
specified in SAE J1403, and remove column three from Table V. However, 
considering that the agency is also proposing a larger test cylinder 
radius for plastic vacuum brake tubing, a longer length of hose 
specimen would be needed for plastic hoses. Therefore, the agency 
proposes that test samples of plastic vacuum brake tubing be 450 mm 
(17.7 inches) in length.

D. Plastic Air Brake Tubing

    1. Overview of Petitions--The agency received four petitions 
regarding plastic air brake tubing in response to the final rule. NHTSA 
also received a letter dated June 19, 2007 from Philatron 
International, asking for changes in plastic air brake tubing 
requirements. Because the letter was not submitted in time to be 
considered a petition for reconsideration, NHTSA will consider 
Philatron's letter to be a petition for rulemaking.
    Each of the organizations petitioning for reconsideration (Degussa, 
Parker Brass Division, Apgar, and Arkema) stated that because the 
agency did not include a requirement that plastic air brake tubing be 
constructed of nylon (polyamide), there are risks that alternate 
materials will not provide adequate long-term service in air brake 
systems. Each petitioner noted that SAE J844, upon which the agency 
based its new requirements for plastic air brake tubing, is based on 
the assumption the nylon specified in that standard has known 
properties that other materials may not possess, such as material 
hardness that could affect end fitting retention. However, the agency 
notes that it went beyond solely the SAE J844 requirements and 
incorporated substantive requirements from SAE

[[Page 57464]]

J1131 as well to address such issues to the extent practicable. The 
agency is not aware of what additional steps it could take to further 
ensure that plastic air brake tubing and end fittings could be more 
compatible.
    Parker stated that the agency's final rule now shifts the burden of 
qualification such that the entity assembling a plastic air brake tube 
to its end fittings must bear the entire burden of compliance, and that 
the final rule changes the business model significantly. The agency 
disagrees. Under the newly adopted requirements of the December 20, 
2004 final rule, there are plastic tubing specifications including 
dimensional requirements, tensile strength, etc., that qualify the 
tubing, and then there are assembly requirements that qualify plastic 
air brake tubing assemblies with the end fittings installed. The 
requirements for assemblers were not changed in the final rule such 
that additional compliance burdens were placed on them.
    Apgar and Arkema cited the efforts of the SAE committee to develop 
SAE J2547 to address specifications for plastic air brake tubing that 
is constructed from materials other than nylon, but the agency notes 
that this effort has been ongoing for several years and work on this 
standard has still not been completed, nor has any draft of that 
standard been provided to the agency. Both companies stated that SAE 
J2547 is still a working document and is only for use within the 
subcommittee. Thus the agency has not been able to consider this 
document in addressing the petitions.
    Degussa, Parker, Apgar, and Arkema all stated that by not adopting 
the nylon (polyamide) material specification from SAE J844, the safety 
of air brake tubing is potentially reduced because alternative 
materials that could be used in air brake tubing may not have the same 
demonstrated performance as nylon. However, as discussed at length in 
the December 20, 2004 final rule (69 FR 76307), the agency has 
determined that the specification of nylon construction would be 
unnecessarily design-restrictive. The agency believes it is more 
appropriate, and enforceable, to measure the pass/fail performance of 
any air brake tubing through appropriate performance tests that are 
included in FMVSS No. 106.
    Degussa, Apgar, and Arkema provided recommendations for additional 
performance tests for plastic air brake tubing. Sources for these 
additional tests include SAE 2260, Nonmetallic Fuel System Tubing, with 
One or More Layers (November 2004); ISO 7628-2, Road Vehicles--
Thermoplastics Tubing for Air Brake Systems (1998); and independent or 
proprietary performance tests that were developed and proposed by the 
commenters. We have reviewed these performance tests and decided that 
certain aspects could be adopted into FMVSS No. 106 and these are 
proposed in this notice for public comment. However, the agency is not 
proposing to adopt the extensive additional performance requirements 
recommended by Arkema and Degussa. In the companion document published 
in today's Federal Register, we are denying substantial portions of 
these petitions.
    2. Plastic Air Brake Tubing Dimensions--Apgar brought to the 
agency's attention that several minor changes to the dimensions of 
plastic air brake tubing were made by the SAE subcommittee in the most 
recent revision of SAE J844 (November 2004). The requirements from SAE 
J1394, Metric Nonmetallic Air Brake Tubing (April 2000) were also 
incorporated into SAE J844 so that one standard would cover both inch-
dimensioned and metric sizes of tubing.
    Apgar submitted changes to the dimensional requirements in Table I 
of SAE J844 that were made in the November 2004 revision of SAE J844. 
These are recommended by Apgar to be adopted into Table VII of FMVSS 
No. 106. The agency is requesting comments on whether to make these 
changes. A notable change to SAE J844, and proposed for FMVSS No. 106, 
is that three sizes of metric tubing (4-mm, 8-mm, and 19-mm) are sized 
the same as three sizes of inch-dimensioned tubing (\5/32\ inch, \5/16\ 
inch, and \3/4\ inch).
    Two of the metric sizes, 4 mm and 19 mm, are new designations for 
metric-sized tubing. 8 mm tubing was previously included in both SAE 
J1394 and in the final rule specifications of FMVSS No. 106. The two 
metric sizes, however, were subsequently moved from SAE J1394 to SAE 
J844, and Apgar submitted revisions from SAE J844 to the \5/16\ inch 
dimensions to make that size of tubing the same as 8-mm tubing. The 
agency proposes to make \5/16\ inch dimensions the same size as 8 mm 
tubing in FMVSS No. 106 in this NPRM and finds that if made final, 
there will be a slight increase (0.8 percent) in the overall diameter 
of \5/16\ inch brake tubing. The agency does not believe this slight 
increase in overall diameter of \5/16\ inch brake tubing will result in 
incompatibility for new tubing manufactured to these dimensions with 
the existing end fittings on motor vehicles, as this change is small, 
but the agency welcomes comments on this issue.
    Since SAE J844 no longer includes measurements in inches, the 
agency has converted dimensions of millimeters to inches and is 
presenting these proposed revisions to Table VII in FMVSS No. 106 in 
this notice. A detailed description of the changes proposed for each 
size of tubing in Table VII is provided below. Unless otherwise noted, 
the dimensional changes provided here, as recommended by Apgar, are 
considered to be very minor deviations from the dimensions published in 
the December 20, 2004 final rule. The changes are on the order of 
hundredths of a millimeter (i.e., from 2.01-mm to 2.02-mm) and 
thousandths of an inch (i.e., from 0.079 inch to 0.080 inch):
    \1/8\ inch O.D.--The maximum O.D. is proposed to change from 3.25 
to 3.26 mm. The inch equivalent is proposed to remain unchanged at 
0.128 inches. The nominal inside diameter is proposed to be changed 
from 2.01 to 2.02 mm. The inch equivalent is proposed to be changed 
from 0.079 to 0.080 inches.
    \5/32\ inch O.D.--The maximum O.D. is proposed to change from 4.04 
to 4.08 mm. The inch equivalent is proposed to change from 0.159 to 
0.161 inches. The minimum O.D. is proposed to change from 3.89 to 3.92 
mm. The inch equivalent is proposed to change from 0.153 to 0.154 
inches. The nominal I.D. is proposed to change from 2.34 to 2.38 mm. 
The inch equivalent then is proposed to change from 0.092 to 0.094 
inches. If made final, these changes would represent a small increase 
in the overall size of \5/32\ inch O.D. tubing. Also, SAE J844 now 
designates this size of tubing as equivalent to metric-sized 4 mm O.D. 
tubing, which is a new size that now appears in that SAE standard. The 
agency proposes that this new size also be incorporated in FMVSS No. 
106.
    \1/4\ inch O.D.--The nominal I.D. is proposed to change from 4.32 
to 4.35 mm. The inch equivalent is proposed to change from 0.170 to 
0.171 inches. The nominal wall thickness is proposed to be changed from 
1.02 to 1.00 mm. The inch equivalent then is proposed to be changed 
from 0.040 to 0.039 inches.
    \5/16\ inch O.D.--The maximum O.D. is proposed to change from 8.03 
to 8.10 mm. The inch equivalent is proposed to be changed from 0.316 to 
0.319 inches. The minimum O.D. is proposed to be changed from 7.82 to 
7.90 mm. The inch equivalent then is proposed to be changed from 0.308 
to 0.311 inches. The nominal I.D. is proposed to be changed from 5.89 
to 6.00 mm. The inch equivalent then is proposed to be changed from 
0.232 to 0.236. The nominal wall thickness is proposed to

[[Page 57465]]

be changed from 1.02 to 1.00 mm. The inch equivalent then is proposed 
to be changed from 0.040 to 0.039 inches. If made final, these changes 
would represent a moderate increase in the overall diameter of \5/16\ 
O.D. tubing, and would make it identical to 8 mm metric-sized air brake 
tubing.
    \3/8\ inch O.D.--The minimum O.D. is proposed to change from 9.42 
to 9.43 mm. The inch equivalent is proposed to remain unchanged at 
0.371 inches. The nominal inside diameter is proposed to change from 
6.38 to 6.39 mm. The inch equivalent is then proposed to change from 
0.251 to 0.252 inches.
    \1/2\ inch O.D.--The nominal I.D. is proposed to change from 9.55 
to 9.56 mm. The inch equivalent is proposed to remain unchanged at 
0.376 inches.
    \5/8\ inch O.D.--The maximum O.D. is proposed to change from 16.00 
to 16.01 mm. The inch equivalent is proposed to remain unchanged at 
0.630 inches.
    \3/4\ inch O.D.--The nominal I.D. is proposed to change from 14.38 
to 14.37 mm. The inch equivalent is proposed to remain unchanged at 
0.566 inches.
    4 mm O.D.--This is a new size of metric-dimensioned air brake 
tubing proposed to be added to Table VII of FMVSS No. 106 as discussed 
above. It is proposed to be identical in size to \5/32\ inch O.D. 
tubing.
    6 mm O.D.--The maximum O.D. is proposed to change from 6.10 to 6.08 
mm. The inch equivalent is proposed to change from 0.240 to 0.239 
inches. The minimum O.D. is proposed to change from 5.90 to 5.92 mm. 
The inch equivalent is then proposed to change from 0.232 to 0.233 
inches. The wall thickness tolerance is proposed to change from 0.10 mm 
to 0.08 mm. The inch equivalent is then proposed to change from 0.004 
to 0.003 inches.
    8 mm O.D.--No changes are proposed for this size of tubing, but 
minor changes to \5/16\ inch O.D. tubing are proposed so that it will 
be identical to 8 mm O.D. tubing, as described above.
    10 mm O.D.--Apgar stated that the nominal I.D. of 7.00 mm as 
published in the agency's final rule is the correct value for this 
dimension. However, the value of 8.50 mm that is in the November 2004 
revision of SAE J844 is in error, and the SAE committee working on that 
standard will make the correction in the next revision of SAE J844. No 
changes to the 10 mm O.D. in FMVSS No. 106 are proposed in this NPRM.
    12 mm O.D.--Apgar stated that the nominal I.D. of 9.00 mm as 
published in the agency's final rule is the correct value for this 
dimension. However, the value of 10.50 mm that is in the November 2004 
revision of SAE J844 is in error, and the SAE committee working on that 
standard will make the correction in the next revision of SAE J844. No 
changes to the 12 mm O.D. in FMVSS No. 106 are proposed in this NPRM.
    19 mm O.D.--This is a new size of metric air brake tubing that is 
proposed to be added to Table VII in FMVSS No. 106. It is proposed to 
be dimensionally identical to \3/4\ inch O.D. tubing as described 
above.
    3. Table VII--Philatron International petitioned the agency to 
amend the tubing dimension requirements by distinguishing air brake 
tubing used in conjunction with replaceable and/or reusable end 
fittings from air brake tubing assemblies manufactured with permanent 
end fittings. Philatron stated that these differences existed prior to 
the agency's December 20, 2004 final rule. Because of the outer 
dimension requirements, there is no longer an allowance for the 
construction of air brake assemblies with permanent end fittings. To 
resolve the situation, Philatron asked that the title of Table VII be 
changed to specifically state that it only applies to air brake tubing 
with reusable end fittings, and the regulatory text of S11.1 
Construction reflect that change.
    NHTSA agrees with Philatron's request. We did not intend to drop 
the distinction between permanent end fittings and those that can be 
reused and/or replaced. However, rather than changing the title of 
Table VII as suggested by the petitioner, the agency proposes to change 
the regulatory text in S11.1 to reflect that the outer dimensions in 
Table VII do not apply to air brake assemblies with permanently 
attached end fittings.
    We propose to add notation to Table VII to indicate that the 
following sizes of tubing are identical, and that they can be labeled 
with either or both size identification labeling: \5/32\ inch and 4mm; 
\5/16\ inch and 8 mm; and \3/4\ inch and 19 mm.
    4. Plastic Air Brake Tubing Mechanical Properties--As the agency is 
proposing to add two new sizes (4 mm and 19 mm) of air brake tubing to 
FMVSS No. 106, it is necessary to provide updates to Table VIII-- 
Plastic Air Brake Tubing Mechanical Properties. The agency proposes to 
adopt the burst strength pressure, supported bend radii, and 
unsupported bend radii for these new sizes of tubing directly from SAE 
J844 as follows:
    4 mm O.D.--The agency proposes to adopt mechanical properties from 
\5/32\ inch tubing that is the same size as 4 mm tubing, as follows: 
Burst strength pressure 8,300 kPa (1,200 psi), supported bend radius 
12.7 mm (0.50 inches), and unsupported bend radius 12.7 mm (0.50 
inches). The proposed conditioned tensile load strength is 178 N (40 
lbf).
    19 mm O.D.--The agency proposes to adopt mechanical properties from 
\3/4\ inch tubing that is the same size as 19 mm tubing, as follows: 
Burst strength pressure 5,500 kPa (800 psi), supported bend radius 76.2 
mm (3.00 inches), and unsupported bend radius 88.9 mm (3.50 inches). 
The proposed conditioned tensile load strength is 1,557 N (350 lbf).
    In addition, the agency proposes to make the following changes to 
the supported and unsupported bend radii for the following sizes of 
plastic air brake tubing that are in agreement with the latest revision 
of SAE J844:
    \5/16\ inch O.D.--Supported bend radius is proposed to be changed 
from 31.8 mm (1.25 inches) to 32.0 mm (1.26 inches).
    6 mm O.D.--Supported bend radius is proposed to be changed from 
20.0 mm (0.75 inches) to 25.4 mm (1.00 inches).
    8 mm O.D.--Supported bend radius is proposed to be changed from 
31.8 mm (1.25 inches) to 32.0 mm (1.26 inches).
    12 mm O.D.--Supported bend radius is proposed to be changed from 
44.5 mm (1.75 inches) to 45.0 mm (1.77 inches). Unsupported bend radius 
is proposed to be changed from 63.5 mm (2.50 inches) to 56.3 mm (2.22 
inches).
    16 mm O.D.--Supported bend radius is proposed to be changed from 
69.9 mm (2.75 inches) to 70.0 mm (2.76 inches). Unsupported bend radius 
is proposed to be changed from 76.2 mm (3.00 inches) to 84.0 mm (3.31 
inches).
    5. Impact Test Apparatus--Since the agency is proposing to revise 
the dimensional specifications for some sizes of tubing, it is also 
necessary to revise the dimensions of the impact test apparatus with 
regard to the hole diameters in its base. The agency has reviewed SAE 
J844 and found that some sizes for the impact test apparatus were 
changed slightly in the November 2004 revision, and references to 4 mm 
and 19 mm brake tubing were added. The agency proposes to change the 
table accompanying Figure 8 in FMVSS No. 106 to reflect the latest 
revisions to J844.
    6. Resistance to Corrosive Salt Compounds--In its final rule to 
amend FMVSS No. 106, the agency included a zinc chloride resistance 
test for plastic air brake tubing in S11.3.12, Zinc Chloride 
Resistance, consisting of immersion of a sample of tubing bent around a 
test cylinder and submerged in a 50 percent zinc chloride aqueous 
solution for 200 hours. The required performance is that the outer 
surface of the tubing shall not show cracks visible under 7-power 
magnification. Such

[[Page 57466]]

cracks are most likely to occur along the bent section of tubing where 
the stresses are highest. This zinc chloride resistance test was based 
on identical requirements in SAE J844.
    Comments to the NPRM indicated that the zinc chloride resistance 
test proposed by the agency, and adopted in the final rule, was not 
particularly severe in evaluating the resistance of plastic materials 
to salts. However, the agency did not adopt any more stringent 
requirements than it had proposed in the NPRM. We are revisiting this 
issue based upon two petitions and also comments received previously in 
response to the NPRM, and are proposing a moderate increase in severity 
of this test requirement by changing to a mixture of five salt 
compounds as specified in ISO 7628-2 Road Vehicles--Thermoplastic 
Tubing for Air Brake Systems (1998-08-15), and by exposing the cut ends 
of tubing to the salt solution.
    In their petitions, both Degussa and Arkema recommended adopting 
the zinc chloride resistance test from SAE J2260, Nonmetallic Fuel 
System Tubing with One or More Layers (November 1, 1996) to FMVSS No. 
106. In section 7.5 of SAE J2260 it states that a sample of plastic 
fuel tubing is prepared with end fittings, bent 180 degrees, and then 
submerged, in a 50 percent aqueous solution of zinc chloride at 23 
degrees Celsius for 200 hours. The requirements are specific in stating 
that the tubing is submerged in the salt solution with both cut ends of 
the tubing submerged, but the solution is not permitted to enter 
through the fittings to the inside of the tubing. This exposes each 
layer of the tubing at its cut ends. Although the agency does not have 
detailed information on the styles of end fittings used with this 
tubing, there is flexibility provided in standard J2260 for the 
selection of end fittings used in this test. This would be a variable 
in the test procedure regarding stresses at the cut ends of the tubing 
because different sizes of end fittings or plugs would impart different 
levels of stress on the tubing depending on how much the ends of the 
tubing are expanded.
    Other than the treatment and exposure of the tubing ends, the 
requirements in J844 are similar to those in J2260 with regard to salt 
solution composition, solution temperature, and exposure time.
    In its petition, Arkema recommends a requirement for test mandrels 
(tubing end plugs) that would be specified for exposing the cut tubing 
ends in salt resistance test. The recommended mandrels described by 
Arkema are in Table X on page 11 of its petition and range from 145 
percent to 130 percent of the nominal inside diameter of the tubing. 
Mandrels of these sizes would substantially expand the tubing and 
induce large stresses at the ends of the tubing. Since plastic air 
brake tubing is not particularly flexible in expansion, inserting 
mandrels of these sizes would require considerable force and would 
result in high stresses at the tubing end. Arkema further recommends 
that tubing manufactured from more than one layer be abraded through at 
least 25 percent of the wall thickness and exposed to zinc chloride.
    We reviewed two SAE standards describing push-to-connect end 
fittings for use with air brake tubing to see if they could provide 
information on the expansion of plastic air brake tubing at the end 
fittings: J2494, Push-to-Connect Tube Fittings for Use in the Piping of 
Vehicular Air Brake; and J2494-2 Dimensional Specifications for Non-
Metallic Body Push-to-Connect Fittings Used on a Vehicular Air Brake 
System. These standards provide external dimensions of push-to-connect 
end fittings but do not provide dimensions of the tube support that is 
inserted into the inside diameter of the tubing during assembly.
    The agency also reviewed SAE J246, Spherical and Flanged Sleeve 
(Compression) Tube Fittings and determined that the tube supports 
described in Table 4 Dimensions of Tube Support, for these fittings are 
smaller than the inside diameter of SAE J844 air brake tubing described 
in Table 1--Dimensions and Tolerances, of that standard. It appears 
that assembling air brake tubing with these end fittings would not 
result in expansion of the ends of the tubing during assembly, and 
therefore these standards do not provide any insight into what size of 
test mandrels might be suitable for use in the salt resistance test.
    The agency believes that the mandrel sizes recommended by Arkema 
that are between 130 and 145 percent of tubing nominal inside diameter 
would be too large for typical plastic air brake tubing, and instead we 
are proposing that the plugs be 5 percent larger than the nominal 
inside diameter of the tubing. The agency believes this specification 
would satisfactorily plug the tubing without inducing excessive 
stresses at the ends of the tubing. The agency also is proposing a 
change to S11.3.12 in FMVSS No. 106 to include submersion of the cut 
ends of the tubing during the immersion of the tubing sample in the 
salt solution. By exposing the cut ends of the tubing, and therefore 
each layer that exists in the tubing, it would not be necessary to 
conduct salt compound resistance tests as recommended by Arkema by 
partially abrading the samples of brake tubing.
    Regarding the composition of the salt solution, the agency is 
proposing to change from a simple zinc chloride salt solution to a 
mixture of salts specified in ISO 7628-2 Road Vehicles--Thermoplastic 
Tubing for Air Brake Systems (1998-08-15). The agency discussed this 
issue in the final rule (69 FR 76310) and noted that comments received 
from DuPont Engineered Polymers and Saint-Gobain Performance Plastics 
in response to the NPRM indicated that those companies believed it may 
be appropriate to consider adopting the salt solution specified in ISO 
7628-2.
    The salt resistance test in Section 7.9 of ISO 7628-2 requires that 
six samples of tubing be bent to a radius of 5.5 times the outside 
diameter of the tubing and then submerged in a salt bath to within 5 mm 
of the cut ends of the tubing. The salt bath consists of a mixture of 
30 percent copper chloride, 20 percent sodium chloride, 20 percent 
potassium chloride, 30 percent zinc chloride, with this mixture added 
to one part water to produce a 50 percent aqueous solution. The bent 
tubing is removed from the salt bath after five minutes and then placed 
in an environmental chamber at a temperature of 60 degrees Celsius (140 
degrees Fahrenheit) and a relative humidity of at least 85 percent for 
24 hours. The immersion and environmental conditioning is repeated for 
a total of 8 cycles (one environmental conditioning period is permitted 
to be 72 hours rather than 24 hours).
    After this conditioning, the tubing is subjected to a burst test at 
23 degrees Celsius (73.4 degrees Fahrenheit) with the required 
performance of withstanding 4 MPa (580 psi) if the tubing is designated 
as 1 MPa (145 psi) tubing or 5 MPa (725 psi) if it is 1.25 MPa (181 
psi) tubing. Annex D of the standard requires testing of the end 
fitting area of the tubing if it is assembled using barbed (fir-tree) 
end fittings and the tubing is constructed of copolyester, but this 
test does not include submerging the cut ends of the tubing in the salt 
bath. It does subject the ends of the tubing to exposure (to within 5 
mm of the cut ends) in an area of high stress where the tubing has been 
expanded over the barbed end fitting. However, the agency is proposing 
to minimize the tubing stress at the cut ends by using plugs that are 
105 percent of the inside diameter of the tubing. Further, the agency 
is not aware of any barbed-type end fittings being used with plastic 
air brake tubing in the U.S.

[[Page 57467]]

    The agency proposes to maintain the 200-hour immersion requirement 
for the salt resistance test in S11.3.12 of FMVSS No. 106. The agency 
invites comments on the proposal to adopt the salt solution from ISO 
7628 into FMVSS No. 106, and to add requirements to test the cut ends 
of plastic tubing by fully immersing the tubing sample in the salt 
solution.
    7. Resistance to Methyl Alcohol--In the final rule, the agency 
adopted the requirements of SAE J844 for resistance to methyl alcohol 
(69 FR 76310). In the test as specified in SAE J844, a sample of tubing 
is bent around a test cylinder of specified radius and the tubing and 
cylinder are immersed in a 95 percent methyl alcohol aqueous solution 
for 200 hours. Upon completing this exposure, the tubing must not 
exhibit cracks on its outer surface when viewed under 7-power 
magnification.
    In its petition for reconsideration, Degussa stated that in both 
the methyl alcohol resistance test and in the zinc chloride resistance 
test (discussed above), each layer of the tubing at the cut ends of the 
tubing should be exposed to these chemical solutions to determine the 
chemical resistance of each layer of the tubing. Since the agency 
believes it is appropriate to expose each layer of tubing during a 
chemical resistance test, we are proposing to modify the methyl alcohol 
resistance test in S11.3.13 to include testing of the cut ends of the 
tubing.
    The agency believes that this is similar to the salt resistance 
test requirements described in the section above since SAE J844 is not 
detailed as to the specific requirements for the cut ends of the 
tubing. The agency proposes to adopt similar requirements for methyl 
alcohol resistance as for corrosive salt resistance by plugging the 
ends of the tubing with plugs having a diameter equal to 105 percent of 
the nominal inside diameter of the tubing and specifying that the 
entire length of tubing be immersed in the methyl alcohol solution.

V. Rulemaking Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and Procedures

    Executive Order 12866, ``Regulatory Planning and Review'' (58 FR 
51735, October 4, 1993), provides for making determinations whether a 
regulatory action is ``significant'' and therefore subject to Office of 
Management and Budget (OMB) review and to the requirements of the 
Executive Order. The Order defines a ``significant regulatory action'' 
as one that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or Tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations or recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    This notice was not reviewed under Executive Order 12866. Further, 
this notice was determined not to be significant within the meaning of 
the DOT Regulatory Policies and Procedures.
    In this document, NHTSA is proposing to incorporate performance 
requirements and test procedures that are based on voluntary standards 
adopted by the Society of Automotive Engineers. The agency believes 
that most, if not all, such hoses, tubing, and fittings are already 
designed to meet the SAE requirements/procedures. However, in the event 
that there are some brake hose products that would need to be modified 
to comply with the proposed regulations, the agency (1) estimates that 
it is a small proportion of brake hose products that would need 
modification, as most are believed to already comply; and (2) 
tentatively concludes that the manufacturers of t