[Federal Register Volume 86, Number 15 (Tuesday, January 26, 2021)]
[Notices]
[Pages 7170-7182]
[FR Doc No: 2021-01539]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

[Docket No. NHTSA-2017-0092]

Mazda North American Operations; Denial of Petition for
Inconsequentiality

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

ACTION: Denial of petition.

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SUMMARY: On July 10, 2017, Takata Corporation (``Takata'') filed a
defect information report (``DIR'') in which it determined that a
safety-related defect exists in phase-stabilized ammonium nitrate
(``PSAN'') driver-side air bag inflators that it manufactured with a
calcium sulfate desiccant and supplied to Ford Motor Company
(``Ford''), Mazda North American Operations (``Mazda''), and Nissan
North America Inc. (``Nissan'') for use in certain vehicles. Mazda's
vehicles identified by Takata's DIR were designed by Ford and were
built on the same platform and using the same air bag inflators as one
of the affected Ford vehicles. Mazda petitioned the Agency for a
decision that the equipment defect determined to exist by Takata is
inconsequential as it relates to motor vehicle safety in the Mazda
vehicles affected by Takata's DIR, and that Mazda should therefore be
relieved of its notification and remedy obligations under the National
Traffic and Motor Vehicle Safety Act of 1966 and its applicable
regulations. After reviewing the petition, NHTSA has concluded that
Mazda has not met its burden of establishing that the defect is
inconsequential to motor vehicle safety, and denies the petition.

ADDRESSES: For further information about this decision, contact Stephen
Hench, Office of Chief Counsel, National Highway Traffic Safety
Administration, 1200 New Jersey Avenue SE, W41-229, Washington, DC
20590 (Tel.<PHONE_NUMBER>).
    For general information about NHTSA's investigation into Takata air
bag inflator ruptures and the related recalls, visit https://www.nhtsa.gov/takata.

SUPPLEMENTARY INFORMATION:

I. Background

    The Takata air bag inflator recalls (``Takata recalls'') are the
largest and most complex vehicle recalls in U.S. history. These recalls
currently involve 19 vehicle manufacturers and approximately 67 million
Takata air bag inflators in tens of millions of vehicles in the United
States alone. The recalls are due to a design defect, whereby the
propellant used in Takata's air bag inflators degrades after long-term
exposure to high humidity and temperature cycling. During air bag
deployment, this propellant degradation can cause the inflator to over-
pressurize, causing sharp metal fragments (like shrapnel) to penetrate
the air bag and enter the vehicle compartment. To date, these rupturing
Takata inflators have resulted in the deaths of 18 people across the
United States \1\ and over 400 alleged injuries, including lacerations
and other serious consequences to occupants' face, neck, and chest
areas.
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    \1\ Globally, including the United States, the deaths of at
least 30 people are attributable to these rupturing Takata
inflators.
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    In May 2015, NHTSA issued, and Takata agreed to, a Consent
Order,\2\ and Takata filed four defect information reports (``DIRs'')
\3\ for inflators installed in vehicles manufactured by twelve \4\
vehicle manufacturers. Recognizing that these unprecedented recalls
would involve many challenges for vehicle manufacturers and consumers,
NHTSA began an administrative proceeding in June 2015 providing public
notice and seeking comment (Docket Number NHTSA-2015-0055). This effort
culminated in NHTSA's establishment

of a Coordinated Remedy Program (``Coordinated Remedy'') in November
2015.\5\ The Coordinated Remedy prioritizes and phases the various
Takata recalls not only to accelerate the repairs, but also--given the
large number of affected vehicles--to ensure that repair parts are
available to fix the highest-risk vehicles first.\6\
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    \2\ The May 2015 Consent Order is available at: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/consent-order-takata-05182015_0.pdf.
    \3\ Recall Nos. 15E-040, 15E-041, 15E-042, and 15E-043.
    \4\ The twelve vehicle manufacturers affected by the May 2015
recalls were: BMW of North America, LLC; FCA US, LLC (formerly
Chrysler); Daimler Trucks North America, LLC; Daimler Vans USA, LLC;
Ford Motor Company; General Motors, LLC; American Honda Motor
Company; Mazda North American Operations; Mitsubishi Motors North
America, Inc.; Nissan North America, Inc.; Subaru of America, Inc.;
and Toyota Motor Engineering and Manufacturing.
    \5\ See Notice of Coordinated Remedy Program Proceeding for the
Replacement of Certain Takata Air Bag Inflators, 80 FR 32197 (June
5, 2015).
    The Coordinated Remedy Order, which established the Coordinated
Remedy, is available at: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/nhtsa-coordinatedremedyorder-takata.pdf. The Third
Amendment to the Coordinated Remedy Order incorporated additional
vehicle manufacturers, that were not affected by the recalls at the
time that NHTSA issued the CRO into the Coordinated Remedy, and is
available at: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/final_public_-_third_amendment_to_the_coordinated_remedy_order_with_annex_a-corrected_12.16.16.pdf. The additional affected vehicle
manufacturers are: Ferrari North America, Inc.; Jaguar Land Rover
North America, LLC; McLaren Automotive, Ltd.; Mercedes-Benz US, LCC;
Tesla Motors, Inc.; Volkswagen Group of America, Inc.; and, per
Memorandum of Understanding dated September 16, 2016, Karma
Automotive on behalf of certain Fisker vehicles.
    \6\ See Coordinated Remedy Order at 15-18, Annex A; Third
Amendment to the Coordinated Remedy Order at 14-17. These documents,
among other documents related to the Takata recalls discussed
herein, are available on NHTSA's website at http://www.nhtsa.gov/takata.
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    Under the Coordinated Remedy, vehicles are prioritized for repair
parts based on various factors relevant to the safety risk--primarily
on vehicle model year (MY), as a proxy for inflator age, and geographic
region. In the early stages of the Takata inflator recalls, affected
vehicles were categorized as belonging to one of two regions: The High
Absolute Humidity (``HAH'') region (largely inclusive of Gulf Coast
states and tropical island states and territories), or the non-HAH
region (inclusive of the remaining states and the District of
Columbia). On May 4, 2016, NHTSA issued, and Takata agreed to, an
amendment to the November 3, 2015 Consent Order (``ACO''), wherein
these geographic regions were refined based on improved understanding
of the risk, and were then categorized as Zones A, B, and C. Zone A
encompasses the higher risk HAH region as well as certain other
states,\7\ Zone B includes states with more moderate climates (i.e.,
lower heat and humidity than Zone A),\8\ and Zone C includes the
cooler-temperature States largely located in the northern part of the
country.\9\
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    \7\ Zone A comprises the following U.S. states and
jurisdictions: Alabama, California, Florida, Georgia, Hawaii,
Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American
Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S.
Virgin Islands. Amendment to November 3, 2015 Consent Order at ]
7.a.
    \8\ Zone B comprises the following U.S. states and
jurisdictions: Arizona, Arkansas, Delaware, District of Columbia,
Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska,
Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma,
Pennsylvania, Tennessee, Virginia, and West Virginia. Amendment to
November 3, 2015 Consent Order at ] 7.b.
    \9\ Zone C comprises the following U.S. states and
jurisdictions: Alaska, Colorado, Connecticut, Idaho, Iowa, Maine,
Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New
York, North Dakota, Oregon, Rhode Island, South Dakota, Utah,
Vermont, Washington, Wisconsin, and Wyoming. Amendment to November
3, 2015 Consent Order at ] 7.c.
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    While the Takata recalls to date have been limited almost entirely
to Takata PSAN inflators that do not contain a desiccant (a drying
agent)--i.e., ``non-desiccated'' inflators--under a November 3, 2015
Consent Order issued by NHTSA and agreed to by Takata, Takata is
required to test its PSAN inflators that do contain a desiccant--i.e.,
``desiccated'' inflators--in cooperation with vehicle manufacturers
``to determine the service life and safety of such inflators and to
determine whether, and to what extent, these inflator types suffer from
a defect condition, regardless of whether it is the same or similar to
the conditions at issue'' in the DIRs Takata had filed for its non-
desiccated PSAN inflators.\10\
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    \10\ Consent Order ] 28.
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    In February 2016, NHTSA requested Ford's assistance in evaluating
Takata calcium-sulfate desiccated PSDI-5 driver-side air bag inflators,
to which Ford agreed.\11\ In June 2016, Ford and Takata began a field-
recovery program to evaluate Takata calcium-sulfate desiccated PSDI-5
driver-side air bag inflators that were original equipment in MY 2007-
2008 Ford Ranger vehicles in Florida, Michigan, and Arizona.\12\ Nissan
also initiated a similar field-recovery program for its Versa vehicles
in March 2016.\13\ By January 2017, a very limited number of samples
from Ford had been recovered and tested.\14\ In March 2017, Takata and
Ford met to review the field data collected from the inflators returned
by Ford and Nissan.\15\ Between March and June 2017, additional Ford
inflators were subjected to live dissection, which included chemical
and dimensional propellant analyses, as well as ballistic testing.\16\
Also in June, Takata reviewed with Ford and NHTSA field-return data
from Ford inflators.\17\ Ford then met with NHTSA on July 6, 2017 to
discuss the data collected to date, as well as an expansion plan for
evaluating Takata calcium-sulfate desiccated PSDI-5 driver-side air bag
inflators.
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    \11\ Mazda has relied upon the Ford testing information because
Mazda's vehicles identified by Takata's DIR were designed by Ford,
built on the same platform, and used the same air bag inflators as
MY 2007-2011 Ford Rangers.
    \12\ See also Recall No. 17E-034. Later, under Paragraph 43 of
the Third Amendment to the Coordinated Remedy Order (``ACRO''),
NHTSA ordered each vehicle manufacturer ``with any vehicle in its
fleet equipped with a desiccated PSAN Takata inflator'' (and not
using or planning to use such an inflator as a final remedy) to
develop a written plan describing ``plans to confirm the safety and/
or service life'' of desiccated PSAN Takata inflators used in its
fleet. ACRO ] 43. Such plans were to include coordination with
Takata for parts recovery from fleet vehicles, testing, and
anticipated/future plans ``to develop or expand recovery and testing
protocols of the desiccated PSAN inflators.'' Id.
    \13\ Recall No. 17V-449. The specific Takata calcium-sulfate
desiccated PSDI-5 driver-side air bag inflators installed in these
Nissan Versa vehicles are a different variant than those installed
in the Ford and Mazda vehicles. There are several differences in
design between the variant installed in Nissan vehicles and the
variants installed in the Ford and Mazda vehicles, which are
discussed further below.
    \14\ Recall No. 17E-034.
    \15\ Id.
    \16\ Id.
    \17\ Id.
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    Takata analyzed 423 such inflators from the Ford program--as well
as 895 such inflators from the Nissan program.\18\ After a review of
field-return data, on July 10, 2017, Takata, determining that a safety-
related defect exists, filed a DIR for calcium-sulfate desiccated PSDI-
5 driver-side air bag inflators that were produced from January 1, 2005
to December 31, 2012 and installed as original equipment on certain
motor vehicles manufactured by Ford (the ``covered Ford inflators''),
as well as calcium-sulfate desiccated PSDI-5 driver-side air bag
inflators for those same years of production installed as original
equipment on motor vehicles manufactured by Nissan (the ``covered
Nissan inflators'') and Mazda (the ``covered Mazda inflators'')
(collectively, the ``covered inflators'').\19\ As described further
below, the propellant tablets in these inflators may experience density
reduction over time, which could result in the inflator rupturing, at
which point ``metal fragments could pass through the air bag cushion
material, which may result in injury or death to vehicle occupants.''
\20\
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    \18\ See Recall No. 17V-449.
    \19\ Recall No. 17E-034.
    \20\ Id.
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    Takata's DIR filing triggered Mazda's obligation to file a DIR for
its affected vehicles.\21\ Mazda filed a corresponding DIR, informing
NHTSA that it intended to file a petition for

inconsequentiality.\22\ Mazda then petitioned the Agency, under 49 CFR
part 556, via letter including an enclosed purported ``joint petition''
with Ford \23\ (``Petition'') for a decision that, because Takata's
analysis of the covered Ford inflators does not show propellant tablet-
density degradation, or increased inflation pressure, and certain
inflator design differences exist between the covered Ford inflators
and the covered Nissan inflators, the equipment defect determined to
exist by Takata is inconsequential as it relates to motor vehicle
safety in the Mazda vehicles affected by Takata's DIR.\24\ In addition,
Mazda requested that NHTSA allow Ford until March 31, 2018 to complete
an ``expanded inflator field study, aging assessment, and testing on
additional samples'' before NHTSA made a decision on the Petition.\25\
Mazda sent its Petition via UPS on August 17, 2017, scheduled to arrive
the following day via next-day air. However, because the Petition was
incorrectly addressed, NHTSA did not receive this copy of the Petition
until August 23, 2017. NHTSA did, however, receive a copy via email on
August 22, 2017.
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    \21\ See 49 U.S.C. 30102(b)(1)(F); 49 CFR part 573; November 3,
2015 Coordinated Remedy Order ]] 45-46. Under 49 CFR 573.5(a), a
vehicle manufacturer is responsible for any safety-related defect
determined to exist in any item of original equipment. See also 49
U.S.C. 30102(b)(1)(C).
    \22\ Mazda Motor Corporation Petition for Determination of
Inconsequentiality of Takata's Defect Information Report filing
under NHTSA Campaign Number 17E-034 for PSDI-5 Desiccated Driver Air
Bag Inflators (dated August 17, 2016) (Mazda appears to have
inadvertently dated its letter August 17, 2016, instead of August
17, 2017) (enclosing ``Mazda submission copy of Part 573'').
    \23\ Ford also submitted a petition to the Agency, with a cover
letter dated August 16, 2017. This petition was not a ``joint
petition'' with Mazda. Ford's petition is addressed in a separate
decision.
    \24\ See Petition at 11-16 and cover letter thereto. The
Petition also suggests differences in ``vehicle environment''
between affected Ford and Nissan vehicles as a potential explanation
for inflator degradation-risk differences between the covered Ford
inflators and the covered Nissan inflators. See Petition at 2.
However, this suggestion is not elaborated on elsewhere. See id. at
14-16 (focusing on design differences between the covered Ford
inflators and covered Nissan inflators).
    \25\ Petition (cover letter).
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    In a Notice published in the Federal Register on November 16, 2017,
NHTSA acknowledged its receipt of Mazda's Petition, opened a public
comment period on the Petition to expire on December 18, 2017, and
denied Mazda's request that the Agency allow Ford until March 31, 2018
to complete certain testing and analysis before the Agency decided on
the Petition.\26\ NHTSA received three comments in response to this
Notice, none of which advocated granting Mazda's Petition.
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    \26\ See 82 FR 53558.
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    Two individual commenters expressed general opposition to granting
the Petition. The third commenter, the Center for Auto Safety
(``CAS''), emphasized the dangers that Takata air bag inflators can
pose, including the PSDI-5 inflators at issue in Mazda's Petition. CAS
also stated a concern that granting Mazda's Petition ``would
effectively serve as a decision that these inflators are exempt from
future recall should additional PSAN testing prove a danger.'' \27\
Specific to the substance of Mazda's Petition,\28\ CAS commented that
it ``contains unsupported assertions as fact, and . . . no
corresponding data or scientific studies confirming the safety of the
PSDI-5 airbag inflators,'' and stated that ``[w]here the petition does
reference the testing conducted by Takata on Ford inflators, there is
little evidence provided to suggest that these inflators will continue
to perform after years of exposure.'' \29\ CAS concluded that, ``[a]t
best, the testing performed by Takata suggests that propellant
degradation and inflator chamber pressure have not yet developed the
potential to harm occupants after ten years in service,'' and that
NHTSA should deny Mazda's Petition.\30\
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    \27\ Comments at 2.
    \28\ CAS's comments collectively addressed the covered Ford and
Mazda inflators.
    \29\ Comments at 2.
    \30\ Id. at 2-3 (emphasis in original).
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    On October 26, 2018, at an in-person meeting with NHTSA, Ford
shared additional information in support of its own separate petition
for the covered Ford inflators,\31\ including internal analyses, test
methodologies, and results of tests performed by Ford and outside
parties on behalf of Ford or at Ford's request.\32\ At a subsequent
virtual meeting with NHTSA on November 4, 2020, Ford shared further
information in support of its Petition related to additional work done
by a third party since October 2018.\33\
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    \31\ See NHTSA docket No. 2017-0093 (regarding Ford's petition).
    \32\ Ford submitted an accompanying slide deck, hereinafter
``October 2018 Presentation.'' This presentation is available on
NHTSA docket No. 2017-0093. The written materials Ford submitted do
not explicitly identify one of these third parties, which his
hereinafter referred to as ``Third Party.''
    \33\ Ford submitted an accompanying slide deck, hereinafter
``November 2020 Presentation.'' This presentation is available on
NHTSA docket No. 2017-0093.
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II. Classes of Motor Vehicles Involved

    Mazda's Petition involves 5,848 vehicles that contain the covered
Mazda inflators.\34\ Those vehicles are MY 2007-2009 B-Series pickup
trucks,\35\ which Mazda explains were built on the same platform and
using the same air bag inflators as Ford MY 2007-2011 Rangers.\36\
Accordingly, Mazda states that although ``Takata has not tested PSDI-5
inflators with calcium sulfate from Mazda vehicles,'' data from those
Ford Rangers is representative of Mazda's MY 2007-2009 B-Series
vehicles.\37\ Ford also stated in its October 2018 and November 2020
presentations to the Agency that the information therein was ``also
representative of airbag inflator performance in shared platforms with
Mazda.''
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    \34\ Petition at 1.
    \35\ Specifically, the petitioned vehicles had a production
range of February 21, 2006 to June 18, 2009. Id.
    \36\ Id.
    \37\ Id. Covered inflators with the prefix ZN were installed in
these Rangers.
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III. Defect

    The defect is present in Takata calcium-sulfate desiccated PSDI-5
driver-side air bag inflators.\38\ According to its DIR, Takata
produced 2.7 million of these defective inflators from January 1, 2005,
to December 31, 2012.\39\ These inflators are the earliest generation
of Takata desiccated PSAN inflators, and were installed as original
equipment in vehicles sold by Ford, Mazda, and Nissan.\40\ The evidence
makes clear that these inflators pose a significant safety risk. In
these inflators, ``[t]he propellant tablets . . . may experience an
alteration over time''--specifically, ``some of the inflators within
the population analyzed show a pattern of propellant density reduction
over time that is understood to predict a future risk of inflator
rupture''--``which could potentially lead to over-aggressive
combustion'' when the air bag in which they are installed deploys.\41\
This ``could create excessive internal pressure, which could result in
the body of the inflator rupturing upon deployment.'' \42\ In the event
of such a rupture, ``metal fragments could pass through the air bag
cushion material, which may result in injury or death to vehicle
occupants.'' \43\ Rupture potentiality may be influenced by ``several
years of exposure to persistent conditions of high absolute humidity,''
as well as other factors, including ``manufacturing variability or
vehicle type.'' \44\
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    \38\ Recall No. 17E-034.
    \39\ Id.
    \40\ Id.
    \41\ Id.
    \42\ Id.
    \43\ Id.
    \44\ Id.
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IV. Legal Background

    The National Traffic and Motor Vehicle Safety Act (the ``Safety
Act''), 49 U.S.C. Chapter 301, defines ``motor vehicle safety'' as
``the performance of a motor vehicle or motor vehicle

equipment in a way that protects the public against unreasonable risk
of accidents occurring because of the design, construction, or
performance of a motor vehicle, and against unreasonable risk of death
or injury in an accident, and includes nonoperational safety of a motor
vehicle.'' \45\ Under the Safety Act, a manufacturer must notify NHTSA
when it ``learns the vehicle or equipment contains a defect and decides
in good faith that the defect is related to motor vehicle safety,'' or
``decides in good faith that the vehicle or equipment does not comply
with an applicable motor vehicle safety standard.'' \46\ The act of
filing a notification with NHTSA is the first step in a manufacturer's
statutory recall obligations of notification and remedy.\47\ However,
Congress has recognized that, under some limited circumstances, a
manufacturer may petition NHTSA for an exemption from the requirements
to notify owners, purchasers, and dealers and to remedy the vehicles or
equipment on the basis that the defect or noncompliance is
inconsequential to motor vehicle safety.\48\
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    \45\ 49 U.S.C. 30102(a)(9).
    \46\ Id. 30118(c)(1). ``[A] defect in original equipment, or
noncompliance of original equipment with a motor vehicle safety
standard prescribed under this chapter, is deemed to be a defect or
noncompliance of the motor vehicle in or on which the equipment was
installed at the time of delivery to the first purchaser.'' 49
U.S.C. 30102(b)(1)(F).
    \47\ Id. 30118-20.
    \48\ Id. 30118(d), 30120(h); 49 CFR part 556.
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    ``Inconsequential'' is not defined either in the statute or in
NHTSA's regulations, and so must be interpreted based on its
``ordinary, contemporary, common meaning.'' \49\ The inconsequentiality
provision was added to the statute in 1974, and there is no indication
that the plain meaning of the term has changed since 1961--meaning
definitions used today are substantially the same as those used in
1974.\50\ The Cambridge Dictionary defines ``inconsequential'' to mean
``not important,'' or ``able to be ignored.'' \51\ Other dictionaries
similarly define the term as ``lacking importance'' \52\ and
``unimportant.'' \53\
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    \49\ See, e.g., Food Mktg. Institute v. Argus Leader Media, 139
S. Ct. 2356, 2363 (2019) (quoting Perrin v. United States, 444 U.S.
37, 42 (1979)).
    \50\ See Public Law 93-492, Title I, Sec.  102(a), 88 Stat. 1475
(Oct. 27, 1974); Webster's Third New Int'l Dictionary (principal
copyright 1961) (defining ``inconsequential'' as ``inconsequent;''
defining ``inconsequent'' as ``of no consequence,'' ``lacking worth,
significance, or importance'').
    The House Conference Report indicates that the Department of
Transportation planned to define ``inconsequentiality'' through a
regulation; however, it did not do so. See H.R. Rep. 93-1191, 1974
U.S.C.C.A.N. 6046, 6066 (July 11, 1974). Instead, NHTSA issued a
procedural regulation governing the filing and disposition of
petitions for inconsequentiality, but which did not address the
meaning of the term ``inconsequential.'' 42 FR 7145 (Feb. 7, 1977).
The procedural regulation, 49 CFR part 556, has remained largely
unchanged since that time, and the changes that have been made have
no effect on the meaning of inconsequentiality.
    \51\ https://dictionary.cambridge.org/us/dictionary/english/inconsequential.
    \52\ https://ahdictionary.com/word/search.html?q=inconsequential.
    \53\ https://www.merriam-webster.com/dictionary/inconsequential.
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    The statutory context is also relevant to the meaning of
``inconsequential.'' \54\ The full text of the inconsequentiality
provision is:
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    \54\ See, e.g., Taniguchi v. Kan Pac. Saipan, Ltd., 566 U.S.
560, 569-72 (2012) (considering ordinary and technical meanings, as
well as statutory context, in determining meaning of a
``interpreter'' under 28 U.S.C. 1920(6)).

    On application of a manufacturer, the Secretary shall exempt the
manufacturer from this section if the Secretary decides a defect or
noncompliance is inconsequential to motor vehicle safety. The
Secretary may take action under this subsection only after notice in
the Federal Register and an opportunity for any interested person to
present information, views, and arguments.\55\
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    \55\ 49 U.S.C. 30118(d), 30120(h).

    As described above, the statute defines ``motor vehicle safety'' to
mean ``the performance of a motor vehicle or motor vehicle equipment in
a way that protects the public against unreasonable risk of accidents .
. . and against unreasonable risk of death or injury in an accident . .
. .'' \56\ This is also consistent with the overall statutory purpose:
``to reduce traffic accidents and deaths and injuries resulting from
traffic accidents.'' \57\
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    \56\ Id. 30102(a)(9) (emphasis added).
    \57\ Id. 30101.
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    The statute explicitly allows a manufacturer to seek an exemption
from carrying out a recall on the basis that either a defect or a
noncompliance is inconsequential to motor vehicle safety.\58\ However,
in practice, substantially all inconsequentiality petitions have
related to noncompliances, and it has been extremely rare for a
manufacturer to seek an exemption in the case of a defect. This is
because a manufacturer does not have a statutory obligation to conduct
a recall for a defect unless and until it ``learns the vehicle or
equipment contains a defect and decides in good faith that the defect
is related to motor vehicle safety,'' or NHTSA orders a recall by
making a ``final decision that a motor vehicle or replacement equipment
contains a defect related to motor vehicle safety.'' \59\ Until that
threshold determination has been made by either the manufacturer or the
Agency, there is no need for a statutory exception on the basis that a
defect is inconsequential to motor vehicle safety. And since a defect
determination involves a finding that the defect poses an unreasonable
risk to safety, asking the Agency to make a determination that a defect
posing an unreasonable risk to safety is inconsequential has heretofore
been almost unexplored.\60\
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    \58\ Id. 30118(d), 30120(h).
    \59\ Id. 30118(c)(1).
    \60\ NHTSA notes that the current petition is different in that
the inflators were declared defective by the supplier of the airbag,
and that Mazda's defect notice was filed in response to the
supplier's notice.
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    Given this statutory context, a manufacturer bears a heavy burden
in petitioning NHTSA to determine that a defect related to motor
vehicle safety (which necessarily involves an unreasonable risk of an
accident, or death or injury in an accident) is nevertheless
inconsequential to motor vehicle safety. In accordance with the plain
meaning of ``inconsequential,'' the manufacturer must show that a risk
posed by a defect is not important or is capable of being ignored. This
appropriately describes the actual consequence of granting a petition
as well. The manufacturer would be relieved of its statutory
obligations to notify vehicle owners and to remedy the defect, and
effectively to ignore the defect as unimportant from a safety
perspective. Accordingly, the threshold of evidence necessary for a
manufacturer to carry its burden of persuasion that a defect is
inconsequential to motor vehicle safety is difficult to satisfy. This
is particularly true where the defect involves a potential failure of
safety-critical equipment, as is the case here.
    The Agency necessarily determines whether a defect or noncompliance
is inconsequential to motor vehicle safety based on the specific facts
before it. The scarcity of defect-related inconsequentiality petitions
over the course of the Agency's history reflects the heavy burden of
persuasion, as well as the general understanding among regulated
entities that the grant of such relief would be quite rare. The Agency
has recognized this explicitly in the past. For example, in 2002, NHTSA
stated that ``[a]lthough NHTSA's empowering statute alludes to the
possibility of an inconsequentiality determination with regard to a
defect, the granting of such a petition would be highly unusual.'' \61\
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    \61\ Letter from J. Glassman, NHTSA, to V. Kroll, Adaptive
Driving Alliance (Sept. 23, 2002), https://www.nhtsa.gov/interpretations/ada3.
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    Of the four known occasions in which the Agency has previously
considered

petitions contending that a defect is inconsequential to motor vehicle
safety, the Agency has granted only one of the petitions, nearly three
decades ago, in a vastly different set of circumstances.\62\ In that
case, the defect was a typographical error in the vehicle's gross
vehicle weight rating (GVWR) that had no impact on the actual ability
of the vehicle to carry an appropriate load. NHTSA granted a motorcycle
manufacturer's petition, finding that a defect was inconsequential to
motor vehicle safety where the GVWR was erroneously described as only
60 lbs., which error was readily apparent to the motorcycle operator
based upon both common sense and the fact that the 330 lbs. front axle
rating and 540 lbs. rear axle rating were listed directly below the
GVWR on the same label.\63\ Moreover, the error did not actually impact
the ability of the motorcycle to carry the weight for which it was
designed.\64\
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    \62\ See id.
    \63\ Suzuki Motor Co., Ltd.; Grant of Petition for
Inconsequential Defect, 47 FR 41458, 41459 (Sept. 20,1982) and 48 FR
27635, 27635 (June 16, 1983).
    \64\ Id.
---------------------------------------------------------------------------

    On the other hand, NHTSA denied another petition concerning a
vehicle's weight label where there was a potential safety impact. NHTSA
denied that petition from National Coach Corporation on the basis that
the rear gross axle weight rating (RGAWR) for its buses was too low and
could lead to overloading of the rear axle if the buses were fully
loaded with passengers.\65\ NHTSA rejected arguments that most of the
buses were not used in situations where they were fully loaded with
passengers and that there were no complaints.\66\ NHTSA noted that its
Office of Defects Investigation had conducted numerous investigations
concerning overloading of suspensions that resulted in recalls, that
other manufacturers had conducted recalls for similar issues in the
past, and that, even if current owners were aware of the issue,
subsequent owners were unlikely to be aware absent a recall.\67\
---------------------------------------------------------------------------

    \65\ Nat'l Coach Corp.; Denial of Petition for Inconsequential
[Defect], 47 FR 49517, 49517 (Nov. 1, 1982). NHTSA's denial was
erroneously titled ``Denial of Petition for Inconsequential
Noncompliance''; the discussion actually addressed the issue as a
defect. See id.; see also Nat'l Coach Corp.; Receipt of Petition for
Inconsequential Defect, 47 FR 4190 (Jan. 28, 1982).
    \66\ Id. at 49517-18.
    \67\ Id. at 49518.
---------------------------------------------------------------------------

    NHTSA also denied a petition asserting that a defect was
inconsequential to motor vehicle safety where the defect involved
premature corrosion of critical structure components (the vehicle's
undercarriage), which could result in a crash or loss of vehicle
control.\68\ Fiat filed the petition preemptively, following NHTSA's
initial decision that certain Fiat vehicles contained a safety-related
defect.\69\ In support of its petition, Fiat argued that no crashes or
injuries resulted from components that failed due to corrosion, and
that owners exercising due diligence had adequate warning of the
existence of the defect.\70\ NHTSA rejected those arguments and both
finalized its determination that certain vehicles contained a safety-
related defect (i.e., ordered a recall) and found that the defect was
not inconsequential to motor vehicle safety.\71\ NHTSA explained that
the absence of crashes or injuries was not dispositive: ``the
possibility of an injury or accident can reasonably be inferred from
the nature of the component involved.'' \72\ NHTSA also noted that the
failure mode was identical to another population of vehicles for which
Fiat was carrying out a recall.\73\ The Agency rejected the argument
that there was adequate warning to vehicle owners, explaining that the
average owner does not inspect the underbody of a car and that interior
corrosion may not be visible.\74\
---------------------------------------------------------------------------

    \68\ Final Determination & Order Regarding Safety Related
Defects in the 1971 Fiat Model 850 and the 1970-74 Fiat Model 124
Automobiles Imported and Distributed by Fiat Motors of N. Am., Inc.;
Ruling on Petition of Inconsequentiality, 45 FR 2134, 2137, 41 (Jan.
10, 1980).
    \69\ Fiat Motors of N. Am., Inc.; Receipt of Petition for
Determination of Inconsequential Defect, 44 FR 60193, 60193 (Oct.
18, 1979); Fiat Motors Corp. of N. Am.; Receipt of Petition for
Determination of Inconsequential Defect, 44 FR 12793, 12793 (Mar. 8,
1979).
    \70\ See, e.g., 45 FR 2134, 2141 (Jan. 10, 1980).
    \71\ Final Determination & Order Regarding Safety Related
Defects in the 1971 Fiat Model 850 and the 1970-74 Fiat Model 124
Automobiles Imported and Distributed by Fiat Motors of N. Am., Inc.;
Ruling on Petition of Inconsequentiality, 45 FR 2137-41 (Jan. 10,
1980). Fiat also agreed to a recall of certain of the vehicles, and
NHTSA found that Fiat did not reasonably meet the statutory recall
remedy requirements. Id. at 2134-37.
    \72\ Id. at 2139.
    \73\ Id.
    \74\ Id. at 2140.
---------------------------------------------------------------------------

    Most recently, the Agency denied a petition asserting that a defect
in non-desiccated Takata PSAN air bag inflators was inconsequential to
motor vehicle safety, where the defect involved the degradation of
inflator propellant that could cause the inflator to over-pressurize
during air bag deployment--causing metal fragments to penetrate the air
bag and enter the vehicle compartment toward vehicle occupants.\75\ In
support of this petition and its argument that the inflators at issue
were not at risk of rupture--being ``more resilient'' to rupture than
other Takata PSAN inflators--General Motors made arguments and
submitted evidence regarding inflator design differences and vehicle
features, testing and field data analyses, inflator aging studies,
predictive modeling, risk assessments, and potential risk created by
conducting repairs.\76\ The Agency rejected these arguments and, among
other things, observed the severe nature of the safety risk and that
the defect could not be discerned even by a diligent vehicle owner.\77\
The Agency also specifically noted the heavy burden on General Motors
to demonstrate inconsequentiality, stating that ``[t]he threshold of
evidence necessary to prove the inconsequentiality of a defect such as
this one--involving the potential performance failure of safety-
critical equipment--is very difficult to overcome.'' \78\
---------------------------------------------------------------------------

    \75\ Gen. Motors LLC, Denial of Consolidated Petition for
Decision of Inconsequential Defect, 85 FR 76159 (Nov. 27, 2020).
    \76\ Id. at 76161-164, 76167.
    \77\ Id. at 76173.
    \78\ Id.
---------------------------------------------------------------------------

    Agency practice over several decades therefore shows that
inconsequentiality petitions are rarely filed in the defect context,
and virtually never granted. Nonetheless, in light of the importance of
the issues here, and the fact that Mazda's defect notification was
filed in response to the notification provided by Mazda's supplier, the
Agency also considered the potential usefulness of the Agency's
precedent on noncompliance. The same legal standard--``inconsequential
to motor vehicle safety''--applies to both defects and
noncompliances.\79\
---------------------------------------------------------------------------

    \79\ 49 U.S.C. 30118(d), 30120(h).
---------------------------------------------------------------------------

    In the noncompliance context, in some instances, NHTSA has
determined that a manufacturer met its burden of demonstrating that a
noncompliance was inconsequential to safety. For example, labels
intended to provide safety advice to an occupant that may have a
misspelled word, or that may be printed in the wrong format or the
wrong type size, have been deemed inconsequential where they should not
cause any misunderstanding, especially where other sources of correct
information are available.\80\ These decisions are similar in nature to
the lone instance where NHTSA granted a

petition for an inconsequential defect, as discussed above.
---------------------------------------------------------------------------

    \80\ See, e.g., Gen. Motors, LLC.; cf. Grant of Petition for
Decision of Inconsequential Noncompliance, 81 FR 92963 (Dec. 20,
2016). By contrast, in Michelin, we reached the opposite conclusion
under different facts. There, the defect was a failure to mark the
maximum load and corresponding inflation pressure in both Metric and
English units on the sidewall of the tires. Michelin N. America,
Inc.; Denial of Petition for Decision of Inconsequential
Noncompliance, 82 FR 41678 (Sept. 1, 2017).
---------------------------------------------------------------------------

    However, the burden of establishing the inconsequentiality of a
failure to comply with a performance requirement in a standard--as
opposed to a labeling requirement--is more substantial and difficult to
meet. Accordingly, the Agency has not found many such noncompliances
inconsequential.\81\ Potential performance failures of safety-critical
equipment, like seat belts or air bags, are rarely deemed
inconsequential.
---------------------------------------------------------------------------

    \81\ Cf. Gen. Motors Corporation; Ruling on Petition for
Determination of Inconsequential Noncompliance, 69 FR 19897, 19899
(Apr. 14, 2004) (citing prior cases where noncompliance was expected
to be imperceptible, or nearly so, to vehicle occupants or
approaching drivers).
---------------------------------------------------------------------------

    An important issue to consider in determining inconsequentiality
based upon NHTSA's prior decisions on noncompliance issues was the
safety risk to individuals who experience the type of event against
which the recall would otherwise protect.\82\ NHTSA also does not
consider the absence of complaints or injuries to show that the issue
is inconsequential to safety.\83\ ``Most importantly, the absence of a
complaint does not mean there have not been any safety issues, nor does
it mean that there will not be safety issues in the future.'' \84\
``[T]he fact that in past reported cases good luck and swift reaction
have prevented many serious injuries does not mean that good luck will
continue to work.'' \85\
---------------------------------------------------------------------------

    \82\ See Gen. Motors, LLC; Grant of Petition for Decision of
Inconsequential Noncompliance, 78 FR 35355 (June 12, 2013) (finding
noncompliance had no effect on occupant safety because it had no
effect on the proper operation of the occupant classification system
and the correct deployment of an air bag); Osram Sylvania Prods.
Inc.; Grant of Petition for Decision of Inconsequential
Noncompliance, 78 FR 46000 (July 30, 2013) (finding occupant using
noncompliant light source would not be exposed to significantly
greater risk than occupant using similar compliant light source).
    \83\ See Combi USA Inc., Denial of Petition for Decision of
Inconsequential Noncompliance, 78 FR 71028, 71030 (Nov. 27, 2013).
    \84\ Morgan 3 Wheeler Ltd.; Denial of Petition for Decision of
Inconsequential Noncompliance, 81 FR 21663, 21666 (Apr. 12, 2016).
    \85\ United States v. Gen. Motors Corp., 565 F.2d 754, 759 (D.C.
Cir. 1977) (finding defect poses an unreasonable risk when it
``results in hazards as potentially dangerous as sudden engine fire,
and where there is no dispute that at least some such hazards, in
this case fires, can definitely be expected to occur in the
future'').
---------------------------------------------------------------------------

    Arguments that only a small number of vehicles or items of motor
vehicle equipment are affected have also not justified granting an
inconsequentiality petition.\86\ Similarly, NHTSA has rejected
petitions based on the assertion that only a small percentage of
vehicles or items of equipment are actually likely to exhibit a
noncompliance. The percentage of potential occupants that could be
adversely affected by a noncompliance does not determine the question
of inconsequentiality. Rather, the issue to consider is the consequence
to an occupant who is exposed to the consequence of that
noncompliance.\87\ These considerations are also relevant when
considering whether a defect is inconsequential to motor vehicle
safety.
---------------------------------------------------------------------------

    \86\ See Mercedes-Benz, U.S.A., L.L.C.; Denial of Application
for Decision of Inconsequential Noncompliance, 66 FR 38342 (July 23,
2001) (rejecting argument that noncompliance was inconsequential
because of the small number of vehicles affected); Aston Martin
Lagonda Ltd.; Denial of Petition for Decision of Inconsequential
Noncompliance, 81 FR 41370 (June 24, 2016) (noting that situations
involving individuals trapped in motor vehicles--while infrequent--
are consequential to safety); Morgan 3 Wheeler Ltd.; Denial of
Petition for Decision of Inconsequential Noncompliance, 81 FR 21663,
21664 (Apr. 12, 2016) (rejecting argument that petition should be
granted because the vehicle was produced in very low numbers and
likely to be operated on a limited basis).
    \87\ See Gen. Motors Corp.; Ruling on Petition for Determination
of Inconsequential Noncompliance, 69 FR 19897, 19900 (Apr. 14,
2004); Cosco Inc.; Denial of Application for Decision of
Inconsequential Noncompliance, 64 FR 29408, 29409 (June 1, 1999).
---------------------------------------------------------------------------

V. Mazda's Petition and Information Before the Agency

    Mazda contends that ``[Ford] Ranger data is representative of B-
Series'': The ``2007-2011 Ford Ranger and 2007-2009 Mazda B-Series
vehicles are built on identical platforms and use identical airbag
inflators'' and, therefore, ``Ford's discussion of Takata's testing and
analysis on 2007-2008 MY Ford Ranger vehicles should apply with equal
force to 2007-2009 MY Mazda B-Series.'' \88\ Similarly, as noted above,
Ford states in its October 2018 and November 2020 Presentations that
information therein is ``also representative of airbag inflator
performance in shared platforms with Mazda.'' Mazda did not separately
submit the subsequent analyses to the Agency, but those submissions do
contain information about the ZN variant inflators found in 2007-2011
Ford Rangers, which Mazda (and Ford) contends is representative of the
2007-2009 Mazda B-Series vehicles at issue here. Therefore, NHTSA has
considered the information derived from the covered Ford inflators
pertaining to the Ford Rangers (prefix ZN)--upon which Mazda relies--as
part of the evidence supporting this decision.
---------------------------------------------------------------------------

    \88\ Petition at 11. Covered inflators with the prefix ZN were
installed in these Rangers.
---------------------------------------------------------------------------

    Taking into account Mazda's Petition and the information presented
by Ford to the Agency in October 2018 and November 2020,\89\ several
arguments underpin Mazda's Petition. In sum: There is a difference in
expected performance between desiccated and non-desiccated Takata PSAN
inflators; that there are design differences between the covered Mazda
inflators and another variant of the same type; that although there are
signs of aging in field returns, there is no indication of propellant
degradation that could lead to rupture and no imminent safety risk; and
that no ruptures of the covered inflators are expected to occur for at
least over twenty-six years of cumulative exposure in the worst-case
environment, for the worst-case vehicle configuration, and worst-case
customer usage. These arguments are supported by analyses recited in
the joint petition with Ford, additional subsequent analyses done by
Ford, results of inflator testing and analyses conducted by three
outside entities, and predictive modeling.
---------------------------------------------------------------------------

    \89\ See NHTSA docket No. 2017-0093.
---------------------------------------------------------------------------

A. Statistical Analysis of MEAF Data

    Ford undertook a statistical analysis of data in the Master
Engineering Analysis File (``MEAF''),\90\ which it and Mazda contend
``shows a clear difference in expected field performance between
desiccated and non-desiccated inflators,'' and ``suggests that the
factors causing degradation in the non-desiccated population of
inflators are not currently affecting'' the inflators at issue.\91\
Four charts underpin these assertions.
---------------------------------------------------------------------------

    \90\ For several years, Takata has inspected, tested, and
analyzed inflators returned from the field. The compiled and
summarized test results for hundreds of thousands of inflators are
contained in the Takata MEAF, which is updated on an ongoing basis.
Takata's MEAF file was available to the Agency in making its
determination, and it is from this file that some of the information
considered by the Agency was derived, and discussed herein.
    \91\ November 2020 Presentation at 11; October 2018 Presentation
at 14.
---------------------------------------------------------------------------

    The first chart is of box plots of primary-chamber pressures of
covered Ford inflators by age, for which it is asserted that there is
``[n]o significant trend of primary pressure increase with inflator
age.'' \92\ The second chart is a lognormal histogram illustrating the
frequency of maximum values of primary-chamber pressure of covered Ford
inflators, which Ford and Mazda assert shows that the probability of a
covered Ford inflator exceeding a 92.37 MPa ``threshold'' \93\ is
estimated as less than 1 x 10-\15\.\94\ A third chart

illustrates predicted primary-chamber pressure for covered Ford
inflators with probability curves for three module ages--15, 20, and 30
years old, for which it is contended shows that the probability of a
module with thirty years in service exceeding a 92.37 MPa threshold is
6.56 x 10-\6\.\95\ And a fourth chart consists of probability plots
(log normalized, 95% confidence) comparing primary-chamber pressure
maximum values between Ford modules with desiccated Takata PSAN
inflators and Ford modules with non-desiccated Takata PSAN
inflators.\96\ Ford and Mazda contend that this shows that the
probability of exceeding a 92.37 MPa threshold for desiccated parts
``is several orders of magnitude lower than that of non-desiccated
parts.'' \97\
---------------------------------------------------------------------------

    \92\ November 2020 Presentation at 7; October 2018 Presentation
at 10.
    \93\ This appears to be the level at which Ford considers an
abnormal deployment to be a potentiality. This 92.37 figure is used
throughout the materials.
    \94\ November 2020 Presentation at 8; October 2018 Presentation
at 11.
    \95\ November 2020 Presentation at 9; October 2018 Presentation
at 12.
    \96\ November 2020 Presentation at 10; October 2018 Presentation
at 13.
    \97\ Id.
---------------------------------------------------------------------------

B. Takata's Live Dissections and Ballistic Testing

    According to Ford and Mazda, Takata analyzed 1,992 calcium-sulfate
desiccated PSDI-5 driver-side air bag inflators returned from the field
from Ford vehicles, which included 1,008 inflators from Ford Ranger
vehicles \98\ and 984 from Fusion/Edge vehicles.\99\ Analysis involved
both live dissections and ballistic testing, with 1,257 inflators
subject to ballistic testing, and 735 inflators subject to live
dissection.\100\ Ford and Mazda conclude from the results that while
``no indication of degradation that could lead to a rupture and no
imminent risk to safety has been identified,'' Takata's analysis did
``identif[y] signs of aging'' in the inflators.\101\
---------------------------------------------------------------------------

    \98\ Mazda noted in its Petition that twenty of these inflators
were from salvage yards ``where the conditions used to store the
parts cannot be determined.'' Petition at 11.
    \99\ November 2020 Presentation at 12; October 2018 Presentation
at 7. Takata also analyzed 895 inflators from Nissan Versa vehicles.
See Recall No. 17V-449; Petition at 11 (``approximately 1,000'').
    \100\ November 2020 Presentation at 12; October 2018
Presentation at 15; see Petition at 14.
    \101\ November 2020 Presentation at 12; October 2018
Presentation at 15.
---------------------------------------------------------------------------

    The nature or results of this ballistic testing and live dissection
were not much further explained in the October 2018 or the November
2020 Presentations. The Petition does, however, further describe such
analyses with respect to the approximately 423 inflators from Ford
Rangers that Takata had analyzed at that point.\102\
---------------------------------------------------------------------------

    \102\ Petition at 14. Twenty of the inflators from Ford Rangers
were from salvage yards ``where the conditions used to store the
parts cannot be determined.'' Id. at 11.
    When Mazda filed its Petition, Takata had analyzed over 1,300 of
its calcium-sulfate desiccated PSDI-5 driver-side air bag inflators:
the approximately 423 inflators from Ford Rangers, and the remainder
from Nissan Versa vehicles. Id. at 14.
---------------------------------------------------------------------------

    The Petition asserts that about 360 live dissections of the Ford
Ranger inflators demonstrated ``consistent inflator output
performance''--specifically, that measurements of ignition-tablet
discoloration, ``generate'' density,\103\ and moisture content of
certain inflator constituents did not indicate a reduction-in-density
trend.\104\ The Petition describes that during visual inspection of the
inflators, ``Takata observed slight discoloration of the propellant
tablets in the primary and secondary chambers,'' but that such
discoloration ``is not an indicant by itself that the propellant has
degraded''--only that the propellant had been exposed to elevated
temperatures.\105\ Takata also observed changes in color in the primary
and secondary booster auto-ignition tablets.\106\ On a scale of 1-10,
with a discoloration of 10 ``indicating severe exposure'' to elevated
temperatures, the Petition states that ``the vast majority'' \107\ of
observed discoloration in inflators obtained from vehicles in certain
high-heat-and-humidity states ``was within the 1-3 range after seven to
eleven years of vehicle service,'' while acknowledging that ``[s]even
samples were in the 5-6 range.'' \108\ Accordingly, the Petition
asserts, the results of visual inspection ``evidence time-in-service,
but not tablet density loss.'' \109\ The Petition also states that
Takata took density measurements of propellant tablets in the primary
and secondary chambers of covered Ford inflators.\110\ ``[A] small
number of samples \111\ were measured with a density slightly below the
minimum average tablet production specification,'' although it was
noted that ``a nearly equal number . . . measured densities higher than
the maximum average tablet production specification.'' \112\ The
Petition argues that such data does ``not support a conclusion that
tablet density is degrading in the inflators designed for Ford after 10
years of service.'' \113\
---------------------------------------------------------------------------

    \103\ The term ``generate'' is utilized throughout the Petition.
See, e.g., Petition at 3 (``generate system'') & 6 (``generate'').
In the Agency's experience, ``generate'' is not among nomenclature
commonly used with respect to air bag inflators--NHTSA is more
familiar with the term ``generant.'' In context, however, it appears
that this is referring to an inflator's function generating gas to
inflate the air bag, or the air bag inflator's propellant itself.
See id.; see also id. at 15 (referring to ``Generate--2004,''
indicating a reference to a particular type of propellant produced
by Takata).
    \104\ Id. at 11-12.
    \105\ Id. at 12.
    \106\ Id.
    \107\ The exact size of this ``vast majority'' was not provided.
    \108\ Petition at 12.
    \109\ Id.
    \110\ Id.
    \111\ Mazda did not state the exact size of this sample.
    \112\ Petition at 12-13.
    \113\ Id. at 13.
---------------------------------------------------------------------------

    The Petition contends that the conclusions therein are further
supported by forty-seven ballistic deployment tests that showed no
inflator exceeding the production primary-chamber pressure performance
specifications.\114\ The results of these tests are, according to the
Petition, consistent with data from newly manufactured PSDI-5 inflators
in Ford vehicles.\115\ The Petition also emphasizes that Takata did not
observe pressure vessel ruptures or pressure excursions on any
desiccated PSDI-5 inflator, and that ``[t]he maximum primary chamber
pressure that Takata measured'' in covered Ford inflators was about 15
MPa lower than that measured in a covered Nissan inflator (which
exhibited primary chamber pressure exceeding 60 MPa).\116\
---------------------------------------------------------------------------

    \114\ Id. at 12-13.
    \115\ Id. at 14.
    \116\ Id.
---------------------------------------------------------------------------

C. ``Design Differences'' in Inflators Equipped in Ford Vehicles

    The Petition contends that ``[t]here are significant design
differences'' in the covered Ford inflators when compared to the
covered Nissan inflators, and that such differences may explain
differences observed between the inflator variants in generate
properties and during testing.\117\ The Petition cites the Ford
inflator variants as having ``fewer potential moisture sources''
because the inflators contain only two, foil-wrapped auto-ignition
tablets (instead of three that are not foil-wrapped), contain divider
disk foil tape, and utilize certain EPDM generate cushion material
(instead of ceramic) that ``reduces generate movement over time,
maintains generate integrity, and leads to consistent and predictable
burn rates.'' \118\ The Petition posits that such differences may
explain differences observed between the two inflator variants'
generate material properties, and ballistic-testing results.\119\
---------------------------------------------------------------------------

    \117\ Id. at 14-15.
    \118\ Id. at 15-16 (providing table).
    \119\ Id. at 14-15; see also November 2020 Presentation at 31;
October 2018 Presentation at 29-30.
---------------------------------------------------------------------------

D. Northrop Grumman's Analysis

    Northrop Grumman (``NG'') analyzed covered Ford inflators, results
of which were presented to the Agency

subsequent to Mazda's filing of its Petition. According to Ford and
Mazda, NG's assessment of field-return parts and modeling ``identified
expected signs of aging but no indication of degradation that could
lead to rupture,'' and the assessment ``identified clear and
significant differences between desiccated and non-desiccated inflators
of similar age and design.'' \120\
---------------------------------------------------------------------------

    \120\ November 2020 Presentation at 13; October 2018
Presentation at 16.
---------------------------------------------------------------------------

    Specifically, NG undertook 58 dissections, 138 tank tests, MEAF
analysis, design comparisons, CT scans, and ballistic modeling. The
inflators subject to dissection and tank tests included inflators from
Ford Rangers (2006-2007, prefix ZN) and Fusions (2006-2008, prefix ZQ)
in South Florida; Edges (2006-2008, prefix ZQ) in South Florida and
Georgia; Rangers (2006-2007, prefix ZN) in Arizona, Rangers in Michigan
(2006-2008, prefix ZN); and virgin inflators (prefixes ZN and ZQ).\121\
---------------------------------------------------------------------------

    \121\ November 2020 Presentation at 14; October 2018
Presentation at 17.
---------------------------------------------------------------------------

    NG also completed probability-of-failure projections for the
covered Ford inflators under its inflator aging model, on which Ford
and Mazda updated the Agency in November 2020.\122\ The results of
those projections were considered in conjunction with anticipated
vehicle attrition and the probabilities of crashes with air bag
deployments.\123\
---------------------------------------------------------------------------

    \122\ November 2020 Presentation at 22.
    \123\ Id.
---------------------------------------------------------------------------

1. Live Dissections
    According to Ford and Mazda, NG performed various assessments
related to live dissections of inflators: \124\
---------------------------------------------------------------------------

    \124\ November 2020 Presentation at 15-16; October 2018
Presentation at 18-19.
---------------------------------------------------------------------------

     Propellant health analysis. According to Ford and Mazda,
the covered Ford inflators are susceptible to energetic disassembly
when tablet density is at 1.64 g/cc or lower,\125\ and the densities of
the tablets from such returned inflators were measured ``well above''
1.63-1.64 g/cc.
---------------------------------------------------------------------------

    \125\ Although not explained, this assertion appears to be
derived from NG's ballistic modeling, which found that ``[a]n
equivalent low press tablet density below 1.631 g/cc was required to
produce sufficient augmented burning.'' See November 2020
Presentation at 17; October 2018 Presentation at 20.
---------------------------------------------------------------------------

     AI-1 analysis. NG measured the propellant tablets for
outer diameter (``OD''), weight, and color. Ford and Mazda state that
the OD and weight of field returns were ``similar'' to virgin
inflators. Also according to Ford, ``[i]n older undesiccated inflators,
the AI-1 tablet color is an indicator of age based on humidity and
temperature exposure in the field, and the returned inflators retained
a 0-2 color (10 the darkest),'' which was ``similar'' to virgin
inflators. Ford and Mazda further note that thermogravimetric analysis
``indicated similar weight loss to virgin samples.''
     Moisture content. According to Ford and Mazda, the
propellants from the returned inflators were lower in moisture content
than non-desiccated PSDI-5 inflators (prefix ZA) and desiccated PSDI-5
(prefix YT) inflators.
     X-ray micro-computed tomography (micro-CT scan). Ford and
Mazda assert that ``[n]o definitive trend was observed with respect to
void count, size, or total volume, and tablet density.'' According to
Ford and Mazda, ``[t]ypically, 20,000 voids were identified ranging in
size from 1 x 10-\5\ to .3 cubic millimeters.''
     Scanning electron microscope (SEM). NG processed 2004
tablets from non-desiccated PSAN inflators (prefix ZA) through the
Independent Testing Coalition's (``ITC'') aging study (1920
cycles).\126\ Those had ``higher surface roughness than tablets from
Ford desiccated inflators.'' Propellant in desiccated PSDI-5 inflators
(prefixes GE and YT) aged at 1920 cycles, according to Ford and Mazda,
also had higher surface roughness than propellant in the field-returned
Ford PSDI-5 inflators (prefixes ZN and ZQ)--which had surface roughness
``similar'' to propellant in virgin inflators.
---------------------------------------------------------------------------

    \126\ The ITC is funded by a consortium of vehicle
manufacturers.
---------------------------------------------------------------------------

     Burn rate (closed bomb). According to Ford and Mazda,
``[n]o significant differences were observed between 2004 propellant
from virgin and returned inflators,'' and ``[n]o anomalous pressure
traces were observed.''
     O-ring. Ford and Mazda state that ``[a]lthough a
significant decrease in [O]-ring squeeze is observed in the 2006-8
PSDI-5D inflator igniter assembly sealing system, the remaining squeeze
is deemed acceptable to prevent moisture leakage around the O-ring.''
According to Ford and Mazda, older O-rings have a loss of resiliency
from a decrease in the horizontal diameter that occurs with increasing
age.
     Inflator Tank Testing. Ford and Mazda state that results
showed one Ford PSDI-5 inflator (ZN prefix) with a chamber pressure
approximately 20% higher than the average of the other tested
inflators. According to Ford and Mazda, ``[a]ll other PSDI-5 ZN curves
were grouped tightly with the virgin inflators,'' as were the ZQ prefix
inflators. Ford and Mazda also note that the inflator with the higher
pressure was from a vehicle in Michigan, and that the pressure ``was
well below any expected inflator rupture pressure.''
2. Ballistic Modeling
    NG developed ballistic models ``to investigate the observed
performance behavior of Ford PSDI-5 ZN and ZQ inflators and to evaluate
the potential sensitivity of the inflators to certain design
deviations.'' \127\ Representative performance models were anchored to
measured pressure data from virgin inflators.\128\ ``The models
simulated inflator ignition, chamber volumetric filling, burst tape
rupture, ignition delay between chambers and steady state combustion.''
\129\ According to Ford and Mazda, the PSDI-5 design required
``significant degradation of the 2004 propellant tablets'' to obtain
failure pressures.\130\ Specifically, ``[a]n equivalent low press
tablet density below 1.631 g/cc was required to produce sufficient
augmented burning.'' \131\ Ford states that such degradation was not
observed in the field returns of covered Ford inflators.\132\
---------------------------------------------------------------------------

    \127\ November 2020 Presentation at 17; October 2018
Presentation at 20.
    \128\ Id.
    \129\ Id.
    \130\ Id.
    \131\ Id.
    \132\ Id.
---------------------------------------------------------------------------

3. MEAF Assessment
    NG analyzed MEAF data up to February 2018 to determine whether
covered Ford inflators had energetic deployment (``ED'') rates were
dependent on platform, inflator age, climate zone, or other
factors.\133\ Among the ``key'' findings according to Ford: For non-
desiccated PSDI-5 inflators, abnormal deployments began to occur after
10.5 years, and EDs after 11.5 years; inflator variants with calcium-
sulfate desiccant experienced normal deployments up to 12.5 years
(which at the time were the oldest inflators contained in the MEAF);
the calcium-sulfate desiccant ``appear[ed] to be largely saturated
after 8 years;'' and the covered Ford inflators contained less moisture
in the 3110 booster propellant than the non-desiccated inflators.\134\
---------------------------------------------------------------------------

    \133\ Id.
    \134\ Id.
---------------------------------------------------------------------------

4. Probability-of-Failure Projections
    In the November 2020 Presentation to the Agency, Ford and Mazda
cite NG's PSAN Inflator Test Program and Predictive Aging Model Final
Report from October 2019 (``NG Model''),\135\

first observing that this report indicates that for another OEM's PSDI-
5 inflator with a calcium-sulfate desiccant (prefix YT), a T3 vehicle
in Miami with the most severe aging (top 1%, hereinafter a ``1% usage''
vehicle), may reach a probability of failure of 1 in 10,000 (.01%) in
less than thirty years.\136\ Ford and Mazda then state that under the
NG model, for the Ford covered inflators prefixes ZN and ZQ, a 1% usage
T3 vehicle in Miami has an expected 25.7 and 25.6 years, respectively,
to a .01% probability of failure.\137\ Ford further states that this is
an additional two years when compared to the YT prefix version of the
inflator (of another OEM).\138\
---------------------------------------------------------------------------

    \135\ NG previously submitted this report to the Agency, which
contains information regarding the safety of desiccated Takata PSAN
inflators. The report is available at https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/ngis_takata_investigation_final_report_oct_2019.pdf.
    \136\ November 2020 Presentation at 23. T3 refers to a
``temperature band.'' Under NG's report, there are three temperature
bands--T1, T2, T3. T3 is the highest temperature band, representing
vehicles with maximum inflator temperatures near or slightly above
70 [deg]C. NG Report at 18-19; see November Presentation at 24. The
``1% usage vehicle'' refers to a vehicle with the most severe
environmental exposure based on customer usage. See November 2020
Presentation at 24.
    \137\ November 2020 Presentation at 25.
    \138\ Id.
---------------------------------------------------------------------------

    Ford and Mazda then assert that the earliest Fusion/Milan/MKZ
vehicles equipped with the covered Ford inflators were built in 2005,
and that if those vehicles perform as T3 vehicles, the earliest
calendar year for a 1 in 10,000 probability of failure is 2031 for a 1%
usage vehicle.\139\ Similarly, Ford and Mazda assert that the earliest
Ranger, Edge/MKX vehicles equipped with the covered Ford inflators were
built in 2006, and that if those vehicles perform as T3 vehicles, the
earliest calendar year for a 1 in 10,000 probability of failure is 2032
for a 1% usage vehicle.\140\
---------------------------------------------------------------------------

    \139\ Id. at 26.
    \140\ Id.
---------------------------------------------------------------------------

    Ford and Mazda build on these assertions by stating that ``for a
rupture to occur the vehicle must be in service and experience a crash
resulting in airbag deployment,'' and that based on vehicle attrition
and crash statistics, Ford and Mazda do not project a field event at
twenty-six years of service.\141\ The below data is provided in
support:\142\
---------------------------------------------------------------------------

    \141\ Id.
    \142\ Id.
    \143\ Ford and Mazda note this was ``[a]djusted for the
population attrition & accident probabilities using vehicles
currently registered in Florida (not all of which have always been
registered in Florida).'' Id.

----------------------------------------------------------------------------------------------------------------
                                                                                Probability of     Expected
                                                                                inflator       cumulative
                     Vehicle                        Model year        Volume       rupture \143\   events at 26
                                                                     (Florida)    at 26 years in     years in
                                                                                service         service
----------------------------------------------------------------------------------------------------------------
Fusion..........................................       2006-2012          75,232        5.08E-07           0.038
MKZ.............................................       2006-2012
Milan...........................................       2006-2011
----------------------------------------------------------------------------------------------------------------
Edge............................................       2007-2010          39,161        6.34E-07           0.025
MKX.............................................       2007-2010
Ranger..........................................       2007-2011
----------------------------------------------------------------------------------------------------------------

    Ford and Mazda therefore state that the earliest a vehicle in a
Miami-type environment may reach a .01% probability of failure is over
a decade in the future for a 1%-usage T3 vehicle and that, in other
words, ``the predictive model suggests that no inflator ruptures are
expected to occur for at least 26 years of cumulative exposure in the
worst case environment, worst case vehicle configuration, and worst
case customer usage'' (i.e., 2031 for the oldest vehicles).\144\
---------------------------------------------------------------------------

    \144\ Id. at 26-27.
---------------------------------------------------------------------------

    Ford and Mazda also make several other observations, including
that: \145\
---------------------------------------------------------------------------

    \145\ Id. at 27.
---------------------------------------------------------------------------

     ``[s]tudying parts prior to approximately 16-18 years in
service would not identify meaningful inflator aging information''
(i.e., 2023 for the oldest vehicles);
     the ITC, in coordination with NG, is conducting a
surveillance program for desiccated Takata PSAN inflators, and data
gathered from that program can validate the NG models;
     ``[w]ith newer inflators that have not yet shown signs of
aging, there is a significant opportunity for improving the fidelity
and accuracy of the model with enhanced anchoring data''; and
     there is time for a separate surveillance program for the
covered Ford inflators ``well before any potential risk is projected''
after the results of NG's surveillance program that are expected in
2021.
    Ford and Mazda conclude that they ``believe[] that the current data
indicates that the subject inflators do not present an unreasonable
risk to safety and that it supports granting the petition.'' \146\
---------------------------------------------------------------------------

    \146\ Id.
---------------------------------------------------------------------------

E. Additional Third-Party Analysis

    According to Ford and Mazda, an additional Third Party found that
no pressure excursions were detected in the covered Ford inflators
analyzed to date.\147\ The Third Party also found that some field
inflators experienced porosity growth greater than virgin inflators
with 2004 propellant, ``but not to a level sufficient to cause pressure
excursions in bomb testing.'' \148\ In addition, ``[n]o significant
increase in tablet ODs was observed for field populations'' of covered
inflators.\149\ These findings were derived from live dissections
performed on 39 inflators and deployment tests on 65 inflators.\150\
The inflators were field-return parts obtained from Florida, Michigan,
and Ohio.\151\
---------------------------------------------------------------------------

    \147\ Id. at 18; October 2018 Presentation at 21.
    \148\ Id.
    \149\ Id.
    \150\ Id.
    \151\ Id.
---------------------------------------------------------------------------

VI. Response to Mazda's Petition and Supporting Information and
Analyses

    Mazda's seeks through its Petition and supporting analysis to show
that the covered Mazda inflators are not at risk of rupture such that
the defect is inconsequential to safety. First, as noted above, when
taking into consideration the Agency's noncompliance precedent, an
important factor is also the severity of the consequence of the defect
were it to occur--i.e., the safety risk to an occupant who is exposed
to an inflator rupture. Mazda did not provide any information to
suggest that result would be any different were a covered Mazda
inflator to rupture in a Mazda vehicle.
    Second, as a general matter, at various points Mazda's Petition
implicitly appears to adopt the covered Nissan inflators as a standard
for

inconsequentiality. However, differentiating the covered Mazda
inflators from the covered Nissan inflators, e.g., through ballistic-
testing or live-dissection results, does not directly answer the
question of whether the defect in the covered Mazda inflators is, on
its own merits, inconsequential to motor vehicle safety. Even assuming
that the covered Mazda inflators compare favorably to the covered
Nissan inflators, NHTSA has not made an inconsequentiality
determination for the covered Nissan inflators--nor will it be doing
so.\152\ It was similarly argued in subsequent materials, for example
with regard to NG's live dissections and predictive-model results, as
well as Ford's statistical analysis of the MEAF, that the covered Ford
inflators compared favorably to other inflator variants, and even to
non-desiccated inflators. Merely demonstrating that one's own defective
product compares favorably to another's defective product does not
suffice for an inconsequentiality determination.
---------------------------------------------------------------------------

    \152\ Ford's comparisons might carry more evidentiary weight if,
for instance, the Agency had previously granted an
inconsequentiality petition from Nissan for its covered inflators.
Nissan did not petition the Agency for an inconsequentiality
determination for its covered inflators. See also 49 CFR 556.4(c)
(requiring such a petition is submitted not later than thirty days
after defect or noncompliance determination).
---------------------------------------------------------------------------

    Relatedly, the argument regarding ``design differences'' between
the covered Ford and covered Nissan inflators appears to be more of an
identification of areas for further study or potential explanation--not
a standalone argument in support of an inconsequentiality
determination. Design differences are identified ``that may account for
the difference in material properties of the generate'' and differences
in pressures measured during ballistic testing of the inflators.\153\
These design differences were not persuasively connected to meaningful
improved performance in generate-properties and pressure differences
\154\ and, even if they were, the covered Nissan inflators are not a
proxy standard for inconsequentiality.
---------------------------------------------------------------------------

    \153\ Petition at 14-15 (emphasis added).
    \154\ Moreover, as described further below, based on recent MEAF
data, one covered Ford inflator has the highest chamber pressure
tested for Takata calcium-sulfate desiccated PSDI-5 inflators.
---------------------------------------------------------------------------

    In addition to these issues, signs of aging were observed in the
covered Ford inflators; the sample sizes used for the analyses were
limited; and there are shortcomings regarding various analyses that
undermine their conclusions--including some information that was
missing or unclear. The probability-of-failure projections are also
unpersuasive, and notably belied by the limited evidence available from
ballistic testing and analysis on real-world field returns of the
covered Ford inflators. These additional issues are discussed below.

A. Signs of Aging

    Ford and Mazda admit that signs of aging were observed in the
covered Ford inflators. While this is indirectly dismissed as a non-
issue--with the conclusion that there is no degradation ``that would
signal either an imminent or developing risk to safety''--aging leads
to degradation, which leads to risk of inflator rupture. Further, the
2004 propellant that is present in the covered Mazda inflators degrades
until, at some point, it no longer burns normally, but in an
accelerated and unpredictable manner that can cause an inflator
rupture. ``The purpose of the Safety Act . . . is to prevent serious
injuries stemming from established defects before they occur.'' \155\
And as CAS commented, ``tests demonstrating that inflators are `OK for
now' in no way ensures safety throughout the maximum useful life of
these vehicles.'' \156\
---------------------------------------------------------------------------

    \155\ United States v. Gen. Motors Corp., 565 F.2d 754, 759
(D.C. Cir. 1977).
    \156\ See Comments at 3.
---------------------------------------------------------------------------

B. Samples

    The Agency finds shortcomings in the sample sizes utilized in the
analyses. The total field-return sample (for ZN and ZQ collectively)
was, across the Takata, NG, and the additional Third Party analyses,
less than 3,000 inflators for an affected population of over 3 million
(Ford) vehicles. Ford and Mazda presented analysis from Takata of fewer
than 2,000 inflators, while NG analyzed only 196, and the additional
Third Party analyzed just over 100. In total, 1,460 ballistic tests are
cited, which is approximately .05% of the total population in which the
covered Ford and Mazda inflators were installed. Specific to the Ford
Ranger, the exact sample size of ZN inflators for all analyses is less
than 1,250.\157\ This figure is approximately .25% of the combined
Ranger and B-Series population (approximately 495,000). By comparison,
for example, those percentages are much smaller than the percentage of
inflators tested as of November 2019 in a mid-sized pick-up vehicle
population equipped with non-desiccated PSAN inflators--1.81%--with one
observed test rupture. Ford's statistical analysis of the MEAF
regarding Pc Primary Max Value frequency \158\ was also based on only
1,247 inflators.\159\
---------------------------------------------------------------------------

    \157\ The exact number of ballistic tests conducted on the ZN-
variant inflators installed in Rangers (and therefore the percentage
of that population of which that number is comprised) is difficult
to discern from the materials submitted to the Agency.
    \158\ See November 2020 Presentation at 8.
    \159\ Moreover, twenty of the inflators (from Ranger vehicles)
were from salvage yards, ``where the conditions used to store the
parts cannot be determined.'' Petition at 11. Further highlighting
the significance of this shortcoming, Mazda noted in its Petition
the potential importance of ``vehicle environment'' with respect to
inflator-degradation risk but did not elaborate on this suggestion
elsewhere in its Petition. See id. at 2; id. 14-16 (focusing on
design differences between the covered Ford inflators and covered
Nissan inflators). For purposes of its arguments related to the NG
Model, Ford and Mazda presented a worst-case scenario, where it was
assumed for purposes of that scenario that the vehicles at issue
would be in the T3 temperature band.
---------------------------------------------------------------------------

C. Additional Underlying Information

    Other shortcomings regarding various analyses presented here--
including some information that was missing or unclear--further
undermine the associated conclusions. These are identifiable in both
Mazda's Petition and in the subsequent Presentations to the Agency.
1. Mazda's Petition
    As an initial matter, Mazda submitted little of the underlying
data, and did not fully explain the underlying methodologies and
results, associated with the arguments in its 2017 Petition. More
specifically, one of the arguments in Mazda's Petition is that Takata's
live dissections of covered Ford inflators does not show tablet-density
degradation or increased inflation pressure, and therefore, Takata
``did not identify a reduction in density trend'' in the covered Ford
inflators.\160\ Tablet discoloration was graded on a qualitative 1-10
scale, but to what discoloration characteristics each level of this
scale corresponds is not explained. And the conclusion that a ``vast
majority'' of discoloration in certain inflators was within a certain
low range of discoloration (with seven samples in a certain mid-range)
is vague, and information about the specific distribution of the
results (e.g., the number of inflators receiving each discoloration
value or the number of inflators in each Zone) was not provided.\161\
---------------------------------------------------------------------------

    \160\ Id. at 11.
    \161\ See id. at 12.
---------------------------------------------------------------------------

    Mazda also provides little information about the specific inflators
tested and associated results with regard to density measurements--such
as actual dimensions, mass, and densities, among measurements--instead
largely relying

on general descriptions of the results.\162\ For inflation pressure,
Mazda offers evidence of ballistic tests, although the breakdown of
this sample with regard to vehicle model year and location, as well as
how many of these inflators were obtained from salvage yards with
unknown environment exposures (and the associated results) was not
provided.\163\
---------------------------------------------------------------------------

    \162\ See id. at 12-13 (``[A] small number of samples were
measured with a density slightly below the minimum average tablet
production specification, while a nearly equal number of samples
measured densities higher than the maximum . . . .'').
    \163\ See id. at 13.
---------------------------------------------------------------------------

2. Subsequent Submissions to the Agency
    The statistical analysis of the MEAF contains several shortcomings
in the first two charts \164\--box plots of primary-chamber pressure by
age of inflator, and a lognormal histogram of maximum values
illustrating the frequency of maximum values of primary-chamber
pressure of covered Ford inflators. In the box plots, it is not
specified or illustrated what a ``normal'' or ``expected'' primary-
chamber pressure would be. Nor is there information showing how many
inflators each age group comprises--although the lack of whiskers in
the box plot for inflators aged thirteen years suggests that, at least
for that age group, the sample size is small. There are also outlier
pressure values observed in the nine- to twelve-year age groups, which
concern the Agency. And in the histogram, results among different
inflator ages are not distinguished--which would have highlighted any
trends in primary-chamber pressure maximum values based on age.
---------------------------------------------------------------------------

    \164\ The presentation of the results of these analyses did not
distinguish between ZN and ZQ inflators.
---------------------------------------------------------------------------

    There are also several shortcomings with the second two charts
\165\--the probability curves for module ages, and probability plots
comparing primary-chamber pressure maximum values of Ford modules with
desiccated and non-desiccated inflators, respectively. As to the
probability curves, while details were not provided, this analysis
appears to assume that degradation will proceed linearly. However,
researchers that have been most closely involved in analyzing Takata
inflators, including NG, all seem to agree that the degradation process
is, at the very least, complex, and does not follow a linear
trajectory. Instead, the 2004 propellant that is present in the covered
Mazda inflators degrades until, at some point, it no longer burns
normally, but in an accelerated and unpredictable manner that can cause
an inflator rupture. As to the probability plots, while a comparison
between desiccated and non-desiccated inflators is somewhat informative
from a broad perspective, it is too general to lend much support to
Mazda's Petition, and as noted above the performance of non-desiccated
Takata PSAN inflators is not a sound benchmark for whether the defect
in the covered Mazda inflators is inconsequential to safety.
---------------------------------------------------------------------------

    \165\ The presentation of the results of these analyses did not
distinguish between ZN and ZQ inflators.
---------------------------------------------------------------------------

    Regarding NG's analysis, as an initial matter, over a quarter of
the 196 inflators analyzed were non-aged/virgin inflators and, further,
degradation would not be expected in the inflators from Michigan (from
which, collectively, 55 of the inflators were obtained). Aging in
inflator O-rings from this analysis is also acknowledged. In addition,
there are several particular issues with NG's live dissections worth
noting. Findings regarding moisture content are of limited value, and
important information on the comparator prefix ZA and YT inflators--
e.g., age and the geographic region in which they were used. As to the
SEM results, it is not explained how the concept of surface roughness
relates to the long-term safety of the inflators at issue here.
Similarly, regarding the additional Third Party's analysis, OD growth
for the tablet grain form has not been found to be reliable indicator
of propellant health, and it is not demonstrated otherwise.

D. Probability-of-Failure Projections

    The probability-of-failure projections are also unpersuasive. As
previously described, these projections, submitted in support of Ford's
Petition in November 2020, are based on the NG Model. While the
projections are informative in various respects, NHTSA does not view
the Model's outputs for the inflators at issue as fully squaring with
the evidence available for those inflators from real-world field
returns \166\--which renders what is provided here unpersuasive for the
purposes of Mazda's Petition. Even with the limited testing evidence
available, ballistic testing of field returns of the covered Ford
inflators includes three inflator deployments with primary-chamber
pressures between 60 and 70 MPa--coming from two ZQ inflators with a
field age between 12 and 13 years (one of which exhibited a pressure of
68 MPa), and one ZN inflator with a field age between 10 and 11
years.\167\ In the Agency's experience, such primary-chamber pressure
results are indicative of propellant degradation and potential future
rupture risk. The nature of these results, in addition to causing
concern, undercuts one of the notable arguments in Mazda's Petition:
That ``[t]he maximum primary chamber pressure that Takata measured'' in
covered Ford inflators was about 15 MPa lower than that measured in a
covered Nissan inflator (which exhibited primary chamber pressure
exceeding 60 MPa). Indeed, at least three covered Ford inflators have
now exceeded 60 MPa in ballistic testing (one ZN, two ZQ), and
according to recent MEAF data, one of these inflators (of the ZQ
variant) has the highest chamber pressure tested for Takata calcium-
sulfate desiccated PSDI-5 inflators.
---------------------------------------------------------------------------

    \166\ While it may be possible to age an inflator artificially
in a manner that replicates aging characteristics in the field (and
then test those inflators), Mazda did not attempt to do this for the
covered Mazda inflators (nor did Ford for the covered Ford
inflators).
    \167\ Also notable is that all three results are over three
standard deviations above even the averagefield-return results for
ZN and ZQ inflators collectively (for which Agency would expect a
higher average than virgin inflators).
    Ford and Mazda also noted a ZN inflator tested by NG with a
chamber pressure approximately 20% higher than the average of the
other inflators in tank testing. The specific measurement (and
measurements of other NG tests) does not appear to have been
provided to the Agency.
---------------------------------------------------------------------------

    Data from the MEAF also may suggest the beginning stages of notable
density changes in propellant tablets in the covered Ford inflators
with increasing field age. Recent results from primary tablets in
inflators with field ages between 12 and 14 years show four inflators
with density measurements near (or below) 1.68 g/cc; according to Ford,
1.64 g/cc is the point at which the PSDI-5 inflators with 2004 tablets
are susceptible to energetic disassembly.\168\ Similarly, there are a
number of field returns measured with secondary-chamber tablet
densities under 1.66 g/cc (mostly ZN, although one ZQ inflator),
including ZN inflators under 1.64 g/cc--one of which was measured as
low as 1.62 g/cc. This undermines the contention that the densities of
the tablets from returned covered Ford inflators were measured ``well
above'' 1.63-1.64 g/cc, as well as assertions regarding the results of
visual inspections that it contends ``evidence time-in-service, but not
tablet density loss.''
---------------------------------------------------------------------------

    \168\ These results regard recently tested ZQ inflators with
greater field ages than previously tested ZN inflators, although it
should also be noted that one ZN inflator with a field age of about
10 years measured a primary-tablet density just above 1.66 g/cc--
lower than any result for a ZQ inflator.
---------------------------------------------------------------------------

    The above results from real-world field returns signal that
propellant degradation in the covered Ford

inflators (and analogous covered Mazda inflators) is occurring. While
the predictive model (and its applicable results) is informative in
certain respects, the specific metrics cited cannot be sufficiently
squared with the actual testing that has been completed on real-world
field returns to be persuasive for Mazda's Petition.\169\
---------------------------------------------------------------------------

    \169\ See also Exhibit A (Report of Dr. Harold Blomquist) to
Gen. Motors LLC, Denial of Consolidated Petition for Decision of
Inconsequential Defect, 85 FR 76159 (Nov. 27, 2020) at para.272
(indicating that--in assessing a similar model with regard to a
petition for inconsequentiality--apparent inconsistencies between
that model's predictions and high-pressure ballistic test results of
field returns (of inflators not at issue here)--``suggest caution
should be used'' in applying the results of that model).
---------------------------------------------------------------------------

    Further, there are shortcomings particular to the metrics on which
Mazda relies regarding the Model. Notably, Ford and Mazda contend that
``there are no expected field events projected at 26 years of
service.'' \170\ However, the figures for an expected number of
cumulative field events \171\ were cut off at 26 years in service and
limited to an analysis of vehicles in Florida--a combined volume of
114,393 vehicles, which is less than 4% of the total population of Ford
vehicles at issue (the specific volume of Rangers in Florida is not
clear from the submitted information).\172\ While such vehicles may be
among the highest risk populations, unless it is assumed that there is
a cumulative zero probability of inflator rupture (through 26 years in
service) for every vehicle in every other State (including States other
than Florida with high heat and humidity),\173\ these calculations do
not reflect the expected cumulative events for the entire population of
3.04 million vehicles installed with calcium-sulfate desiccated Takata
inflators through 26 years in service \174\--thereby understating the
risk, as suggested by the Model, for the vehicles at issue. In other
words, there is not a fleet-level assessment here--the total number of
cumulative events expected to occur in the coming years. And in any
case, these metrics are undercut by the ballistic results and analysis
of field-returned inflators showing elevated pressures and propellant
density changes discussed above.
---------------------------------------------------------------------------

    \170\ See November 2020 Presentation at 26.
    \171\ These figures, which appear based on the twenty-sixth year
of service (the point at which, under the NG Model and according to
Ford and Mazda, there is a 1% probability of failure for a covered
Ford inflator in a T3 vehicle with the most severe (top 1%) usage
factors in Miami), were 0.038 for a population of approximately
75,000 Fusion, MKZ, and Milan vehicles, and 0.025 for a population
of approximately 39,000 Edge, MKX, and Ranger vehicles. See November
2020 Presentation at 26.
    \172\ Evidence was not submitted demonstrating that none of the
vehicles subject to the Petition would be in service after 26
years--in Florida or otherwise. And while relevant metrics were
adjusted for attrition and crash probabilities, specific information
about how these adjustments were made was also not submitted.
    \173\ Although 26 years is--under the NG Model and according to
Ford and Mazda--the point at which there is a 1% probability of
failure for a covered Ford inflator in a T3 vehicle with the most
severe (top 1%) usage factors in Miami, Ford and Mazda do not
explain why this is an appropriate point at which to end the
analysis of the expected number of cumulative field events.
    \174\ Similarly, no such calculation was provided specific to
the Ford Ranger population installed with ZN inflators.
---------------------------------------------------------------------------

VII. Decision

    The relief sought here is extraordinary. Mazda's Petition is quite
distinct from previous petitions discussed above relating to defective
labels that may (or may not) mislead the user of the vehicle to create
an unsafe condition.\175\ Nor is the risk here comparable to a
deteriorating exterior component of vehicle that--even if an average
owner is unlikely to inspect the component--might (or might not) be
visibly discerned.\176\ Rather, similar to the defect at issue in
NHTSA's recent decision on a petition regarding certain non-desiccated
Takata PSAN air bag inflators installed in General Motors vehicles, the
defect here poses an unsafe condition caused by the degradation of an
important component of a safety device that is designed to protect
vehicle occupants in crashes.\177\ Instead of protecting occupants,
this propellant degradation can lead to an uncontrolled explosion of
the inflator and propel sharp metal fragments toward occupants in a
manner that can cause serious injury and even death.\178\ This unsafe
condition--hidden in an air bag module--is not discernible even by a
diligent vehicle owner, let alone an average owner.\179\
---------------------------------------------------------------------------

    \175\ See Nat'l Coach Corp.; Denial of Petition for
Inconsequential [Defect], 47 FR 49517 (Nov. 1, 1982); Suzuki Motor
Co., Ltd.; Grant of Petition for Inconsequential Defect, 48 FR 27635
(June 16, 1983).
    \176\ See Final Determination & Order Regarding Safety Related
Defects in the 1971 Fiat Model 850 and the 1970-74 Fiat Model 124
Automobiles Imported and Distributed by Fiat Motors of N. Am., Inc.;
Ruling on Petition of Inconsequentiality, 45 FR 2134 (Jan. 10,
1980).
    \177\ See Gen. Motors LLC, Denial of Consolidated Petition for
Decision of Inconsequential Defect, 85 FR 76159 (Nov. 27, 2020).
    \178\ See id. at 76173; cf. Gen. Motors, LLC; Grant of Petition
for Decision of Inconsequential Noncompliance, 78 FR 35355-01, 2013
WL 2489784 (June 12, 2013) (finding noncompliance inconsequential
where ``occupant classification system will continue to operate as
designed and will enable or disable the air bag as intended'').
    \179\ See Gen. Motors LLC, Denial of Consolidated Petition for
Decision of Inconsequential Defect, 85 FR 76159, 76173 (Nov. 27,
2020); Final Determination & Order Regarding Safety Related Defects
in the 1971 Fiat Model 850 and the 1970-74 Fiat Model 124
Automobiles Imported and Distributed by Fiat Motors of N. Am., Inc.;
Ruling on Petition of Inconsequentiality, 45 FR 2134 (Jan. 10, 1980)
(rejecting argument there was adequate warning to vehicle owners of
underbody corrosion, as the average owner does not undertake an
inspection of the underbody of a vehicle, and interior corrosion of
the underbody may not be visible).
---------------------------------------------------------------------------

    NHTSA has been offered no persuasive reason to think that without a
recall, even if current owners are aware of the defect and instant
petition, subsequent owners of vehicles equipped with covered Mazda
inflators would be made aware of the issue.\180\ This is not the type
of defect for which notice alone enables an owner to avoid the safety
risk. A remedy is required to address the underlying safety defect.
---------------------------------------------------------------------------

    \180\ See Nat'l Coach Corp.; Denial of Petition for
Inconsequential [Defect], 47 FR 49517 (Nov. 1, 1982) (observing,
inter alia, that other manufacturers had conducted recalls for
similar issues in the past, and that, even if current owners were
aware of the issue, subsequent owners were unlikely to be aware
absent a recall).
---------------------------------------------------------------------------

    As discussed above, threshold of evidence necessary to prove the
inconsequentiality of a defect such as this one--involving the
potential performance failure of safety-critical equipment--is very
difficult to overcome.\181\ Mazda bears a heavy burden, and the
evidence and argument it provides suffers from numerous, significant
deficiencies, as previously described in detail. In all events, the
information that Mazda presents in its Petition and that which is in
the subsequent Presentations to the Agency is inadequate to support a
grant of Mazda's Petition.
---------------------------------------------------------------------------

    \181\ See Gen. Motors LLC, Denial of Consolidated Petition for
Decision of Inconsequential Defect, 85 FR 76159, 76173 (Nov. 27,
2020).
---------------------------------------------------------------------------

    As noted above, at various points, Mazda's Petition appears to
focus on differentiating the covered Ford inflators from the covered
Nissan inflators--not directly answering the question of whether the
defect in the covered Ford inflators (and the covered Mazda inflators)
is, on its own merits, inconsequential to motor vehicle safety. It was
similarly argued in subsequent materials that the covered Ford
inflators compared favorably to another inflator variant of the same
type, and even to non-desiccated inflators. These comparisons do not
suffice for an inconsequentiality determination. Relatedly, the
argument regarding design differences does not suffice to support an
inconsequentiality determination. This argument, furthermore, was not
persuasively connected to meaningful improved performance in generate-
properties and pressure differences (and even if it had

been, the covered Nissan inflators are not an appropriate proxy
standard for inconsequentiality). The sample sizes used for the
analyses were also limited, and there are shortcomings regarding
various analyses that undermine their conclusions--including some
information was missing or unclear.
    As a general matter, signs of aging were observed, which leads to
propellant degradation, which leads to inflator rupture--and the 2004
propellant that is present in the covered Mazda inflators degrades
until, at some point, it no longer burns normally, but in an
accelerated and unpredictable manner that can cause an inflator
rupture. Perhaps most importantly, even with the limited testing
evidence available, ballistic testing of field returns of the covered
Ford inflators includes three inflator deployments with primary-chamber
pressures between 60 and 70 MPa--coming from two ZQ inflators with a
field age between 12 and 13 years (one of which exhibited a pressure of
68 MPa), and one ZN inflator with a field age between 10 and 11 years.
Data from the MEAF also appears to indicate the beginning stages of
density changes in propellant tablets in the inflators with increasing
field age. These results from real-world field returns signal that
propellant degradation is occurring, and belie the probability-of-
failure projections provided in November 2020 (which have their own
additional shortcomings that would lead to an understatement of the
potential risk).
    Given the severity of the consequence of propellant degradation in
these air bag inflators--the rupture of the inflator and metal shrapnel
sprayed at vehicle occupants--a finding of inconsequentiality to safety
demands extraordinarily robust and persuasive evidence. What Mazda
presents here, while valuable and informative in certain respects,
suffers from far too many shortcomings, both when the evidence is
assessed individually and in its totality, to demonstrate that the
defect in covered Mazda inflators is not important or can otherwise be
ignored as a matter of safety.
    In consideration of the forgoing, NHTSA has decided Mazda has not
demonstrated that the defect is inconsequential to motor vehicle
safety. Accordingly, Mazda's Petition is hereby denied, and Mazda is
obligated to provide notification of, and a remedy for, the defect
pursuant to 49 U.S.C. 30118 and 30120. Within 30 days of the issuance
of this decision, Ford shall submit to NHTSA a proposed schedule for
the notification of vehicle owners and the launch of a remedy required
to fulfill those obligations.

    Authority: 49 U.S.C. 30101, et seq., 30118, 30120(h), 30162,
30166(b)(1), 30166(g)(1); delegation of authority at 49 CFR 1.95(a);
49 CFR parts 556, 573, 577.

Jeffrey Mark Giuseppe,
Associate Administrator for Enforcement.
[FR Doc. 2021-01539 Filed 1-25-21; 8:45 am]
BILLING CODE 4910-59-P