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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 9 & 82
[FRL-xxxx-x]
Protection of Stratospheric Ozone
AGENCY:  Environmental Protection Agency
ACTION:  Notice of Proposed Rulemaking

SUMMARY:  This action proposes restrictions or prohibitions on
substitutes for ozone depleting substances (ODSs) under the U.S.
Environmental Protection Agency (EPA) Significant New
Alternatives Policy (SNAP) program.  SNAP implements section 612
of the amended Clean Air Act of 1990 which requires EPA to
evaluate and regulate substitutes for the ODSs to reduce overall
risk to human health and the environment.  Through these
evaluations, SNAP generates lists of acceptable and unacceptable
substitutes for each of the major industrial use sectors.  The
intended effect of the SNAP program is to expedite movement away
from ozone depleting compounds while avoiding a shift into high-
risk substitutes posing other environmental problems.  
         On March 18, 1994, EPA promulgated a final rulemaking
setting forth its plan for administering the SNAP program (59 FR
13044), and issued decisions on the acceptability and
unacceptability of a number substitutes.  In this Notice of
Proposed Rulemaking (NPRM), EPA is issuing its preliminary
decisions on the acceptability of certain substitutes not
previously reviewed by the Agency.  To arrive at determinations
on the acceptability of substitutes, the Agency completed a
cross-media evaluation of risks to human health and the
environment by sector end-use.  
         Today's action proposes new additions to the list of
controlled or prohibited substitutes.  As described in the final
rule for the SNAP program (59 FR 13044), EPA does believe that
notice-and-comment rulemaking is required to place any
alternative on the list of prohibited substitutes, to list an
alternative as acceptable only under certain use conditions or
certain narrow end-use applications.
         EPA does not, however, believe that rulemaking procedures
are required to list alternatives as acceptable with no
limitations.  Such listings do not impose any sanction, nor do
they remove any prior license to use a substitute.  Consequently,
EPA is adding substitutes to the list of acceptable alternatives
without first requesting comment on new listings.  Updates to the
acceptable lists are published as separate notices in the Federal
Register.  A comprehensive compilation of all listings will be
published annually.
DATES:  Written comments or data provided in response to this
document must be submitted by November 10, 1994. 
ADDRESSES:  Written comments and data should be sent to Docket A-
91-42, Central Docket Section, South Conference Room 4, U.S.
Environmental Agency, 401 M Street, S.W., Washington, D.C. 
20460.  The docket may be inspected between 8 a.m. and 4:00 p.m.
on weekdays.  Telephone (202) 260-7549.  As provided in 40 CFC
part 2, a reasonable fee may be charged for photocopying.  To
expedite review, a second copy of the comments should be sent to
Sally Rand, Stratospheric Protection Division, Office of
Atmospheric Programs, U.S. EPA, 401 M Street, S.W., 6205-J,
Washington, D.C. 20460.  Information designated as Confidential
Business Information (CBI) under 40 CFR, part 2 subpart B must be
sent directly to the contact person for this notice.  However,
the Agency is requesting that all respondents submit a non-
confidential version of their comments to the docket as well. 
FOR FURTHER INFORMATION CONTACT:  Sally Rand at (202) 233-9739 or
fax (202) 233-9577, Substitutes Analysis and Review Branch,
Stratospheric Protection Division, Office of Atmospheric
Programs, Office of Air and Radiation, Washington, D.C.  
SUPPLEMENTARY INFORMATION:
I.  Overview of This Action
         This action is divided into five sections, including this
overview:
           I.     Overview of This Action
          II. Section 612 Program
                  A.  Statutory Requirements
                  B.  Regulatory History
         III.     Proposed Listing of Substitutes
          IV.     Executive Order 12866
           V.     Additional Information
         Appendix A:  Summary of Proposed Listing Decisions
II. Section 612 Program
         A.       Statutory Requirements
         Section 612 of the Clean Air Act authorizes EPA to develop
a
program for evaluating alternatives to ozone-depleting
substances.  EPA is referring to this program as the Significant
New Alternatives Policy (SNAP) program.  The major provisions of
section 612 are: 
         .        Rulemaking--Section 612(c) requires EPA to
promulgate
                  rules making it unlawful to replace any class I
                  (chlorofluorocarbon, halon, carbon tetrachloride,
                  methyl chloroform, methyl bromide, and
                  hydrobromofluorocarbon) or class II
                  (hydrochlorofluorocarbon) substance with any
substitute
                  that the Administrator determines may present
adverse
                  effects to human health or the environment where
the
                  Administrator has identified an alternative that
(1)
                  reduces the overall risk to human health and the
                  environment, and (2) is currently or potentially
                  available.
         .        Listing of Unacceptable/Acceptable
Substitutes--Section
                  612(c) also requires EPA to publish a list of the
                  substitutes unacceptable for specific uses.  EPA
must
                  publish a corresponding list of acceptable
alternatives
                  for specific uses.
         .        Petition Process--Section 612(d) grants the right
to
                  any person to petition EPA to add a substitute to
or
                  delete a substitute from the lists published in
                  accordance with section 612(c).  The Agency has
90 days
                  to grant or deny a petition.  Where the Agency
grants
                  the petition, EPA must publish the revised lists
within
                  an additional 6 months.   
         .        90-day Notification--Section 612(e) requires EPA
to
                  require any person who produces a chemical
substitute
                  for a class I substance to notify the Agency not
less
                  than 90 days before new or existing chemicals are
                  introduced into interstate commerce for
significant new
                  uses as substitutes for a class I substance.  The
                  producer must also provide the Agency with the
                  producer's unpublished health and safety studies
on
                  such substitutes.
         .        Outreach--Section 612(b)(1) states that the
                  Administrator shall seek to maximize the use of
federal
                  research facilities and resources to assist users
of
                  class I and II substances in identifying and
developing
                  alternatives to the use of such substances in key
                  commercial applications.
         .        Clearinghouse--Section 612(b)(4) requires the
Agency to
                  set up a public clearinghouse of alternative
chemicals,
                  product substitutes, and alternative
manufacturing
                  processes that are available for products and
                  manufacturing processes which use class I and II
                  substances.
         B.       Regulatory History
         On March 18, 1994, EPA published the Final Rulemaking
(FRM)
(59 FR 13044) which described the process for administering the
SNAP program and issued EPA's first acceptability lists for
substitutes in the major industrial use sectors.  These sectors
include:  refrigeration and air conditioning; foam blowing;
solvent cleaning; fire suppression and explosion protection;
sterilants; aerosols; adhesives, coatings and inks; and tobacco
expansion.  These sectors comprise the principal industrial
sectors that historically consume large volumes of ozone-
depleting compounds.
         The Agency defines a "substitute" as any chemical,
product,
substitute, or alternative manufacturing process, whether
existing or new, that could replace a class I or class II
substance.  Anyone who produces a substitute must provide the
Agency with health and safety studies on the substitute at least
90 days before introducing it into interstate commerce for
significant new use as an alternative.  This requirement applies
to chemical manufacturers, but may include importers, formulators
or end-users when they are responsible for introducing a
substitute into commerce.  
III.     Proposed Listing of Substitutes
         To develop the lists of unacceptable and acceptable
substitutes, EPA conducts screens of health and environmental
risks posed by various substitutes for ozone-depleting compounds
in each use sector.  The outcome of these risks screens can be
found in the public docket, as described above in the Addresses
portion of this notice.  
         Under section 612, the Agency has considerable discretion
in
the risk management decisions it can make in SNAP.  The Agency
has identified five possible decision categories:  acceptable,
acceptable subject to use conditions; acceptable subject to
narrowed use limits; unacceptable; and pending.  Acceptable
substitutes can be used with no limits for all applications
within the relevant sector end-use.  Conversely, it is illegal to
replace an ODS with a substitute listed by SNAP as unacceptable. 
A pending listing represents substitutes for which the Agency has
not received complete data or has not completed its review of the
data.
         After reviewing a substitute, the Agency may make a
determination that a substitute is acceptable only if conditions
of use are met to minimize risks to human health and the
environment.  Use of such substitutes in ways that are
inconsistent with such use conditions renders these substitutes
unacceptable.
         Even though the Agency can restrict the use of a
substitute
based on the potential for adverse effects, it may be necessary
to permit a narrowed range of use within a sector end-use because
of the lack of alternatives for specialized applications.  Users
intending to adopt a substitute acceptable with narrowed use
limits must ascertain that other acceptable alternatives are not
technically feasible.  Companies must document the results of
their evaluation, and retain the results on file for the purpose
of demonstrating compliance.  This documentation shall include
descriptions of substitutes examined and rejected, processes or
products in which the substitute is needed, reason for rejection
of other alternatives, e.g., performance, technical or safety
standards, and the anticipated date other substitutes will be
available and projected time for switching to other available
substitutes.  Use of such substitutes in application and end-uses
which are not specified as acceptable in the narrowed use limit
renders these substitutes unacceptable.
         In this Notice of Proposed Rulemaking (NPRM), EPA is
issuing
its preliminary decision on the acceptability of certain
substitutes not previously reviewed by the Agency.  As described
in the final rule for the SNAP program (59 FR 13044), EPA
believes that notice-and-comment rulemaking is required to place
any alternative on the list of prohibited substitutes, to list a
substitute as acceptable only under certain use conditions or
narrowed use limits, or to remove an alternative from either the
list of prohibited or acceptable substitutes.  
         EPA does not believe that rulemaking procedures are
required
to list alternatives as acceptable with no limitations.  Such
listings do not impose any sanction, nor do they remove any prior
license to use a substitute.  Consequently, EPA is adding
substitutes to the list of acceptable alternatives without first
requesting comment on new listings.  Updates to the acceptable
and pending lists are published as separate notices in the
Federal Register.
         Parts A. through E. below present a detailed discussion of
the substitute listing determinations by major use sector. 
Tables summarizing listing decisions in this Notice of Proposed
Rulemaking are in Appendix A.  The comments contained in Appendix
A provide additional information on a substitute.  Since comments
are not part of the regulatory decision, they are not mandatory
for use of a substitute.  Nor should the comments be considered
comprehensive with respect to other legal obligations pertaining
to the use of the substitute.  However, EPA encourages users of
acceptable substitutes to apply all comments in their use of
these substitutes.  In many instances, the comments simply allude
to sound operating practices that have already been identified in
existing industry and/or building-code standards.  Thus, many of
the comments, if adopted, would not require significant changes
in existing operating practices for the affected industry.
         A.       Refrigeration and Air Conditioning
                  1.       Overview
         The refrigeration and air conditioning sector includes all
uses of class I and class II substances to produce cooling,
including mechanical and non-mechanical refrigeration, air
conditioning, and heat transfer.  Please refer to the final SNAP
rule (59 FR 13044) for a more detailed description of this
sector.
         The refrigeration and air conditioning sector is divided
into the following end-uses:
                 commercial comfort air conditioning;
                 industrial process refrigeration systems;
                 industrial process air conditioning;
                 ice skating rinks;
                 uranium isotope separation processing;
                 cold storage warehouses;
                 refrigerated transport;
                 retail food refrigeration;
                 vending machines;
                 water coolers;
                 commercial ice machines;
                 household refrigerators;
                 household freezers;
                 residential dehumidifiers;
                 motor vehicle air conditioning;
                 residential air conditioning and heat
pumps;
                 non-mechanical heat transfer;
                  and
                 very low temperature refrigeration.
In addition, each end-use is divided into retrofit and new
equipment applications.  EPA has not necessarily reviewed
substitutes in every end-use for this NPRM.
         EPA has modified the list of end-uses for this sector for
this SNAP update.  First, EPA has changed the name of the heat
transfer end-use to non-mechanical heat transfer.  This change is
intended to avoid confusion between systems that move heat from a
cool area to a warm one (mechanical refrigeration) and systems
that simply aid the movement of heat away from warm areas (non-
mechanical heat transfer). The second change is that EPA added a
new end-use, very low temperature refrigeration.  Substitutes for
this end-use have been reviewed since the final rule, and
therefore have been added for this SNAP update.  Finally, EPA has
also reviewed substitutes for CFC-13, R-13B1, and R-503
industrial process refrigeration.  Please refer to the final SNAP
rule (59 FR 13044)  for a detailed description of end-uses other
than these three.  EPA may continue to add other end-uses in
future SNAP updates.
                           a.       Non-mechanical Heat Transfer
         As discussed above, this end-use includes all cooling
systems that rely on a fluid to remove heat from a heat source to
a cooler area, rather than relying on mechanical refrigeration to
move heat from a cool area to a warm one.  Generally, there are
two types of systems: systems with fluid pumps, referred to as
recirculating coolers, and those that rely on natural convection
currents, known as thermosyphons.
                           b.       Very Low Temperature
Refrigeration
         Medical freezers, freeze-dryers, and other small
appliances
require extremely reliable refrigeration cycles.  These systems
must meet stringent technical standards that do not normally
apply to refrigeration systems.  They usually have very small
charges.  Because they operate at very high vapor pressures, and
because performance is critically affected by any charge loss,
standard maintenance for these systems tends to reduce leakage to
a level considerably below that for other types of refrigeration
and air conditioning equipment.
                           c.       CFC-13, R-13B1, and R-503
Industrial Process
                                    Refrigeration
         This end-use differs from other types of industrial
refrigeration only in the extremely low temperature regimes that
are required.  Although some substitutes may work in both these
extremely low temperatures and in systems designed to use R-502,
they are acceptable only for this end-use because of global
warming and atmospheric lifetime concerns.  These concerns are
discussed more fully below.
                  2.       Substitutes for Refrigerants
         Substitutes fall into eight broad categories.  Seven of
these categories are chemical substitutes used in the same vapor
compression cycle as the ozone-depleting substances being
replaced.  They include hydrochlorofluorocarbons (HCFCs),
hydrofluorocarbons (HFCs), hydrocarbons, refrigerant blends,
ammonia, perfluorocarbons (PFCs), and chlorine systems.  The
eighth category includes alternative technologies that generally
do not rely on vapor compression cycles.  Please refer to the
final SNAP rule (59 FR 13044) for more discussion of these broad
categories.
                           a.       Acceptable Subject to Use
Conditions
                                    (1)      CFC-12 Automobile and
Non-automobile
                                             Motor Vehicle Air
Conditioners, Retrofit
                                             and New
         EPA is concerned that the existence of several substitutes
in this end-use may increase the likelihood of significant
refrigerant cross-contamination and potential failure of both air
conditioning systems and recovery/recycling equipment.  In
addition, a smooth transition to the use of substitutes strongly
depends on the continued purity of the recycled CFC-12 supply. 
In order to prevent cross-contamination and preserve the purity
of recycled refrigerants, EPA is proposing several conditions on
the use of all motor vehicle air conditioning refrigerants.  For
the purposes of this rule, no distinction is made between
"retrofit" and "drop-in" refrigerants;  retrofitting a car to use
a new refrigerant includes all procedures that result in the air
conditioning system using a new refrigerant.
         In particular, when retrofitting a CFC-12 system to use
any
substitute refrigerant, the following conditions must be met:
                 Each refrigerant may only be used with a set of
                  fittings that is unique to that refrigerant. 
These
                  fittings (male or female, as appropriate) must be
used
                  with all containers of the refrigerant, on can
taps, on
                  recovery, recycling, and charging equipment, and
on all
                  air conditioning system service ports.  These
fittings
                  must be designed to mechanically prevent
cross-charging
                  with another refrigerant.  A refrigerant may only
be
                  used with the fittings and can taps specifically
                  intended for that refrigerant.  Using an adapter
or
                  deliberately modifying a fitting to use a
different
                  refrigerant will be a violation of this use
condition. 
                  In addition, fittings shall meet the following
                  criteria, derived from Society of Automotive
Engineers
                  (SAE) standards and recommended practices:
                  -        When existing CFC-12 service ports are
to be
                           retrofitted, conversion assemblies shall
attach to
                           the CFC-12 fitting with a thread lock
adhesive
                           and/or a separate mechanical latching
mechanism in
                           a manner that permanently prevents the
assembly
                           from being removed.
                  -        All conversion assemblies and new
service ports
                           must satisfy the vibration testing
requirements of
                           sections 3.2.1 or 3.2.2 of SAE J1660, as
                           applicable, excluding references to SAE
J639 and
                           SAE J2064, which are specific to
HFC-134a.
                  -        In order to prevent discharge of
refrigerant to
                           the atmosphere, systems shall have a
device to
                           limit compressor operation before the
pressure
                           relief device will vent refrigerant. 
This
                           requirement is waived for systems that
do not
                           feature such a pressure relief device.
                  -        All CFC-12 service ports shall be
retrofitted with
                           conversion assemblies or shall be
rendered
                           permanently incompatible for use with
CFC-12
                           related service equipment by fitting
with a device
                           attached with a thread lock adhesive
and/or a
                           separate mechanical latching mechanism
in a manner
                           that prevents the device from being
removed.
                 When a retrofit is performed, a label must be used
as
                  follows:
                  -        The person conducting the retrofit must
apply a
                           label to the air conditioning system in
the engine
                           compartment that contains the following
                           information:
                           *        the name and address of the
technician and
                                    the company performing the
retrofit
                           *        the date of the retrofit
                           *        the trade name, charge amount,
and, when
                                    applicable, the ASHRAE
refrigerant numerical
                                    designation of the refrigerant
                           *        the type, manufacturer, and
amount of
                                    lubricant used
                           *        if the refrigerant is or
contains an ozone-
                                    depleting substance, the
statement "This
                                    refrigerant contains an
ozone-depleting
                                    substance and it is therefore
subject to the
                                    venting prohibition, recycling,
and other
                                    provisions of regulations
issued under
                                    section 609 of the Clean Air
Act."
                           *        if the refrigerant is not or
does not contain
                                    any ozone-depleting substances,
the statement
                                    "This refrigerant does not
deplete
                                    stratospheric ozone, and as of
November 15,
                                    1995, at the latest, it is
subject to the
                                    venting prohibition, recycling,
and other
                                    provisions of regulations
issued under
                                    section 609 of the Clean Air
Act."
                           *        if the refrigerant displays
flammability
                                    limits as measured according to
ASTM E681,
                                    the statement "This refrigerant
is FLAMMABLE. 
                                    Take appropriate precautions."
                  -        This label must be large enough to be
easily read
                           and must be permanent.
                  -        The background color must be unique to
the
                           refrigerant.
                  -        The label must be affixed to the system
over
                           information related to the previous
refrigerant,
                           in a location not normally replaced
during vehicle
                           repair.
                  -        Information on the previous refrigerant
that
                           cannot be covered by the new label must
be
                           permanently rendered unreadable.
                 No substitute refrigerant may be used to "top-off"
a
                  system that uses another refrigerant.  The
original
                  refrigerant must be recovered in accordance with
                  regulations issued under section 609 of the CAA
prior
                  to charging with a substitute.
         Since these use conditions necessitate unique fittings and
labels, it will be necessary for developers of automotive
refrigerants to consult with EPA about the existence of other
alternatives.  Such discussions will lower the risk of
duplicating fittings already in use.
         No determination guarantees satisfactory performance from
a
refrigerant.  Consult the original equipment manufacturer or
service personnel for further information on using a refrigerant
in a particular system.
                                             (a)      HFC-134a
         HFC-134a is acceptable as a substitute for CFC-12 in
retrofitted and new motor vehicle air conditioners, subject to
the use conditions applicable to motor vehicle air conditioning
described above.  HFC-134a does not contribute to ozone
depletion.  HFC-134a's GWP and atmospheric lifetime are close to
those of other alternatives which have been determined to be
acceptable for this end-use.  However, HFC-134a's contribution to
global warming could be significant in leaky end-uses such as
motor vehicle air conditioning systems (MVACS).  EPA has
determined that the use of HFC-134a in these applications is
acceptable because industry continues to develop technology to
limit emissions.  In addition, the number of available
substitutes for use in MVACS is currently limited.  HFC-134a is
not flammable and its toxicity is low.  While HFC-134a is
compatible with most existing refrigeration and air conditioning
equipment parts, it is not compatible with the mineral oils
currently used in such systems.  An appropriate ester-based,
polyalkylene glycol-based, or other type of lubricant should be
used.  Consult the original equipment manufacturer or the
retrofit kit manufacturer for further information.
                                             (b)      R-401C
         R-401C, which consists of HCFC-22, HFC-152a, and HCFC-124,
is acceptable as a substitute for CFC-12 in retrofitted and new
motor vehicle air conditioners, subject to the use conditions
applicable to motor vehicle air conditioning described above. 
HCFC-22 and HCFC-124 contribute to ozone depletion, but to a much
lesser degree than CFC-12.  The production of HCFC-22 will be
phased out according to the accelerated phaseout schedule
(published 12/10/93, 58 FR 65018).  The GWP of HCFC-22 is
somewhat higher than other alternatives for this end-use. 
Experimental data indicate that HCFC-22 may leak through flexible
hosing in mobile air conditioners at a high rate.  In order to
preserve the blend's composition and to reduce its contribution
to global warming, EPA strongly recommends using barrier hoses
when hose assemblies need to be replaced during a retrofit
procedure.  The GWPs of the other components are low.  Although
this blend does contain one flammable constituent, the blend
itself is not flammable.  Leak testing demonstrated that the
blend never becomes flammable.
                                             (c)      HCFC Blend
Beta
         HCFC Blend Beta is acceptable as a substitute for CFC-12
in
retrofitted and new motor vehicle air conditioners, subject to
the use conditions applicable to motor vehicle air conditioning
described above.  The composition of this blend has been claimed
confidential by the manufacturer.  This blend contains at least
one HCFC, and therefore contributes to ozone depletion, but to a
much lesser degree than CFC-12.  Regulations regarding recycling
and reclamation issued under section 609 of the Clean Air Act
apply to this blend.  Its production will be phased out according
to the accelerated schedule (published 12/10/93, 58 FR 65018). 
The GWPs of the components are moderate to low.  This blend is
nonflammable, and leak testing has demonstrated that the blend
never becomes flammable.
                           b.       Acceptable Subject to Narrowed
Use Limits
                                    (1)      Non-mechanical Heat
Transfer, New and
                                             Retrofit
                                             (a)     
Perfluorocarbons
         Perfluorocarbons are proposed acceptable as substitutes
for
CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115 in new and
retrofitted thermosyphons and recirculating coolers only where no
other alternatives are technically feasible due to safety or
performance requirements.  PFCs covered by this determination are
C3F8, C4F10, C5F12, C5F11NO, C6F14, C6F13NO, C7F16, C7F15NO, C8F18,
C8F16O, AND
C9F21N.  PFCs offer high dielectric resistance and they are low in
toxicity and nonflammable.  The principal characteristic of
concern for PFCs is that they have long atmospheric lifetimes and
have the potential to contribute to global climate change.  For
instance, C5F12 has a lifetime of 4,100 years and a 100-year GWP
of 5,600.  PFCs are also included in the Climate Change Action
Plan which broadly instructs EPA to use section 612 of the CAA,
as well as voluntary programs, to control emissions.  Despite
these concerns, EPA is proposing to list PFCs as acceptable in
certain small applications because they may be the only
substitutes that can satisfy safety or performance requirements. 
For example, a transformer may require very high dielectric
strength, or a heat transfer system for a chlorine manufacturing
process could require compatibility with the process stream.
         Users should note, however, that use of a PFC should be a
last resort.  As the proposed determination states, PFCs should
be used "only where no other alternatives are technically
feasible due to safety or performance requirements."  This
statement requires users to conduct a thorough search for other
substitutes.  Although EPA does not require users to submit
information on such a search, companies must keep the results on
file for future reference.
         In cases where users must adopt PFCs, they should make
every
effort to:
                 Recover and recycle these fluids during
servicing
                 Adopt maintenance practices that reduce
leakage as much
                  as is technically feasible
                 Recover these fluids after the end of the
equipment's
                  useful life and either recycle them or destroy
them
                 continue to search for other long-term
alternatives
Users of PFCs should note that if other alternatives become
available, EPA could be petitioned to list PFCs as unacceptable
due to the availability of other suitable substitutes.  If such a
petition were granted, EPA may grandfather existing uses but only
upon consideration of cost and timing of testing and
implementation of new substitutes.  In addition, while this
listing allows for use of PFCs in some new systems, a petition
indicating widespread design of systems using PFCs where other
alternatives exist could adversely impact any grandfathering
decisions.
         EPA believes these end-uses are covered under section 608
of
the CAA and encourages voluntary compliance with the recycling
and leak repair provisions of that rule until new rulemakings
specifically address non-ozone-depleting refrigerants.
                           c.       Unacceptable Substitutes
                                    (1)      R-403B
         R-403B, which consists of HCFC-22, R-218, and propane, is
proposed unacceptable as a substitute for R-502 in the following
new and retrofitted end-uses:
                 industrial process refrigeration;
                 cold storage warehouses;
                 refrigerated transport;
                 retail food refrigeration;
                 commercial ice machines; and
                 household freezers.
R-218, perfluoropropane, has an extremely high GWP and lifetime. 
Although this substitute may offer energy efficiency gains, its
lifetime and direct GWP pose additional risk beyond that of other
substitutes for these end-uses.  In particular, the lifetime of
R-218 is over 2000 years, which means that global warming and
other effects would be essentially irreversible.  EPA believes
that while other substitutes may have high GWPs, they do not
exhibit such long lifetimes.
                                    (2)      R-405A
         R-405A, which is composed of HCFC-22, HFC-152a, HCFC-142b,
and R-c318, is proposed unacceptable as a substitute for CFC-12,
R-500, and R-502 in the following new and retrofitted end-uses:
                 commercial comfort air conditioning;
                 industrial process refrigeration;
                 ice skating rinks;
                 cold storage warehouses;
                 refrigerated transport;
                 retail food refrigeration;
                 vending machines;
                 water coolers;
                 commercial ice machines;
                 household refrigerators;
                 household freezers;
                 residential dehumidifiers; and
                 motor vehicle air conditioning.
R-405A was listed as HCFC/HFC/fluoroalkane Blend A in previous
notices.  R-405A contains a high proportion of R-c318,
cycloperfluorobutane, which has an extremely high GWP and
lifetime.  Although this substitute may offer energy efficiency
gains, its lifetime and direct GWP pose additional risk beyond
that of other substitutes for these end-uses.  In particular, the
lifetime of R-c318 is over 3000 years, which means that global
warming and other effects would be essentially irreversible.  EPA
believes that while other substitutes may have high GWPs, they do
not exhibit such long lifetimes.
                                    (3)      Hydrocarbon Blend B
Hydrocarbon Blend B is proposed unacceptable as a substitute for
CFC-12 in the following new and retrofitted end-uses:
                 commercial comfort air conditioning;
                 ice skating rinks;
                 cold storage warehouses;
                 refrigerated transport;
                 retail food refrigeration;
                 vending machines;
                 water coolers;
                 commercial ice machines;
                 household refrigerators;
                 household freezers;
                 residential dehumidifiers; and
                 motor vehicle air conditioning.
Flammability is the primary concern.  EPA believes the use of
this substitute in very leaky uses like motor vehicle air
conditioning may pose a high risk of fire.  EPA requires a risk
assessment be conducted to demonstrate this blend may be safely
used in any CFC-12 end-uses.  The manufacturer of this blend has
not submitted such a risk assessment, and EPA therefore finds it
unacceptable.
                                    (4)      Flammable substitutes
         Flammable substitutes, defined as having flammability
limits
as measured according to ASTM E-681 with modifications included
in Society of Automotive Engineers Recommended Practice J1657,
including blends which become flammable during fractionation, are
proposed unacceptable as substitutes for CFC-12 in retrofitted
motor vehicle air conditioning systems.
         Flammable refrigerants differ from traditional substances
in
several ways: potential gains in energy efficiency, reductions in
direct contribution to global warming, and additional risks from
fire.  Flammable refrigerants may be good substitutes in systems
designed with fire risks in mind.  In addition, in certain
circumstances, they may serve well as substitutes in retrofit
uses.  EPA encourages research efforts into the use of flammable
refrigerants, but remains concerned about the dangers.  Because
of these concerns, EPA has established the requirement that
manufacturers of flammable refrigerants conduct detailed risk
assessments in all end-uses.  The risks from flammability are
extremely sensitive to the size of charge and end-use.
         In MVACS, flammable refrigerants pose risks not found in
stationary equipment, including the potential for collisions, the
placement of the condenser directly behind the grille, flexible
hoses which could be punctured, the hazard to technicians who are
expecting to handle flammable fluids, the danger to passengers
from evaporator leaks, and the dangers to personnel involved in
disposal of old automobiles.  Due to the length of SNAP review,
certain substitutes have been marketed which EPA believes may
pose substantial risk to users.  The intent of the 90-day review
process was not to allow manufacturers to market risky
substitutes, but rather to ensure a thorough review.  Because of
potential risks to users and service personnel, EPA finds it
necessary to find all flammable substitutes unacceptable in
retrofitted automotive air conditioning to prevent hazardous
substitutes from being marketed prior to a thorough risk
assessment.
         EPA continues to encourage investigation of all substitute
refrigerants, including flammable substances.  This unacceptable
determination only applies to retrofitted MVACS.  If a
manufacturer wishes an acceptable determination for a flammable
substitute in MVACS, this risk assessment must be conducted in a
scientifically valid manner.  EPA will consider such a risk
assessment in any determination on the substitute.
         B.  Solvents
                  1.  Acceptable Subject to Use Conditions
                           a.  Electronics Cleaning                
                      
                                    (1)  HCFC-225 ca/cb
         HCFC-225 is proposed acceptable subject to use conditions
as
a substitute for CFC-113 and MCF in electronics cleaning.  The 
HCFC-225 ca isomer has a  company-set exposure limit of 25 ppm. 
The company set exposure limit of the HCFC-225 cb isomer is 250
ppm.  These limits should be readily achievable since HCFC-225 is
only sold commercially as a (45%/50%) blend  of -ca and -cb
isomers.    In addition, the vapor degreasing and cold cleaning
equipment where HCFC-225 is used, typically has very low
emissions.
                           b.  Precision Cleaning
                                    (1)  HCFC-225 ca/cb
         HCFC-225 is proposed acceptable subject to use conditions
as
a substitute for CFC-113 and MCF in precision cleaning.  The 
HCFC-225 ca isomer has a  company-set exposure limit of 25 ppm. 
The company set exposure limit of the HCFC-225 cb isomer is 250
ppm.  These limits should be readily achievable since HCFC-225 is
only sold commercially as a (45%/50%) blend  of -ca and -cb
isomers.    In addition, the vapor degreasing and cold cleaning
equipment where HCFC-225 is used, typically has very low
emissions.  
                  2.  Unacceptable Substitutes 
                           a.  Metals Cleaning
                                    (1)  Dibromomethane
         Dibromomethane is proposed as an unacceptable substitute
for
CFC-113 and MCF in metals cleaning.  Dibromomethane has a
comparatively high ODP and other alternatives exist which do not
pose comparable risk.
                           b.  Electronics Cleaning
                                    (2)  Dibromomethane
         Dibromomethane is proposed as an unacceptable substitute
for
CFC-113 and MCF in electronics cleaning.  Dibromomethane has a
comparatively high ODP and other alternatives exist.
                           c.  Precision Cleaning
                                    (3)  Dibromomethane
         Dibromomethane is proposed as an unacceptable substitute
for
CFC-113 and MCF in precision cleaning.  Dibromomethane has a
comparatively high ODP and other alternatives exist.
         C.       Fire Suppression and Explosion Protection
                  1.       Proposed Acceptable Subject to Use
Conditions
                           a.       Total Flooding Agents
                                    (1)      C3F8 
         C3F8 is proposed acceptable as a Halon 1301 substitute
where
other alternatives are not technically feasible due to
performance or safety requirements: a) due to their physical or
chemical properties or b) where human exposure to the agents may
approach cardiosensitization levels or result in other
unacceptable health effects under normal operating conditions. 
This proposed agent is subject to the same use conditions
stipulated for all total flooding agents, that is:
                 Where egress from an area cannot be
accomplished within
one minute, the employer shall not use this agent in
concentrations exceeding its NOAEL.
                 Where egress takes longer than 30 seconds
but less than
one minute, the employer shall not use the agent in a
concentration greater than its LOAEL.
                 Agent concentrations greater than the LOAEL
are only
permitted in areas not normally occupied by employees provided
that any employee in the area can escape within 30 seconds.  The
employer shall assure that no unprotected employees enter the
area during agent discharge.  
         Cup burner tests in heptane indicate that C3F8 can
extinguish
fires in a total flood application at concentrations of 7.30 per
cent and therefore has a design concentration of 8.8 per cent. 
The cardiotoxicity NOAEL of 30 per cent for this agent is well
above its extinguishment concentration and therefore is safe for
use in occupied areas.  This agent can replace Halon 1301 by a
ratio of 2 to 1 by weight.
         Using agents in high concentrations poses a risk of
asphyxiation by displacing oxygen.  With an ambient oxygen level
of 21 per cent, a design concentration of 22.6 per cent may
reduce oxygen levels to approximately 16 per cent, the minimum
level considered to be required to prevent impaired judgement or
other physiological effects.  Thus, the oxygen level resulting
from discharge of this agent must be at least 16 per cent.
         C3F8 has no ozone depletion potential, and is
nonflammable,
essentially non-toxic, and is not a VOC.  However, this agent has
an atmospheric lifetime of 3,200 years and a 100-year GWP of
6100.  Due to the long atmospheric lifetime of C3F8, the Agency is
finding this chemical acceptable only in those limited instances
where no other alternative is technically feasible due to
performance or safety requirements.  In most total flooding
applications, the Agency believes that alternatives to C3F8 exist. 
EPA intends that users select C3F8 out of need and that this agent
be used as the agent of last resort.  Thus, a user must determine
that the requirements of the specific end-use preclude use of
other available alternatives.
         Users must observe the limitations on C3F8 acceptability
by
undertaking the following measures:  (i) conduct an evaluation of
foreseeable conditions of end use; (ii) determine that human
exposure to the other alternative extinguishing agents may
approach or result in cardiosensitization or other unacceptable
toxicity effects under normal operating conditions; and (iii)
determine that the physical or chemical properties or other
technical constraints of the other available agents preclude
their use.
         EPA recommends that users minimize unnecessary emissions
of
this agent by limiting testing of C3F8 to that which is essential
to meet safety or performance requirements; recovering C3F8 from
the fire protection system in conjunction with testing or
servicing; and destroying or recycling C3F8 for later use.  EPA
encourages manufacturers to develop aggressive product
stewardship programs to help users avoid such unnecessary
emissions.
                                    (2)      CF3I
         CF3I is proposed acceptable as a Halon 1301 substitute in
normally unoccupied areas.  Any employee that could possibly be
in the area must be able to escape within 30 seconds.  The
employer shall assure that no unprotected employees enter the
area during agent discharge.  
         CF3I (Halon 13001) is a fluoroiodocarbon with an
atmospheric
lifetime of only 1.15 days due to its rapid photolysis in the
presence of light.  The resulting GWP of this agent is less than
one, and its ODP when released at ground level is likely to be
extremely low, with current conservative estimates ranging from
.008 to .01.  Complete analysis of the ozone depleting potential
of this agent will be available in the near future.
         Anticipating EPA's concern about releases of CF3I from
aircraft, and the associated likelihood of a higher ODP value
when released at altitude, the military has conducted an analysis
of historical releases of Halon 1301 from both military and
commercial aircraft.  Initial assessment indicate that emissions
from U.S. military aircraft  appear to have averaged about 56
pounds annually, of which 2 pounds were emitted above 30,000
feet.  Commercial aircraft worldwide released an estimated
average of 933 pounds of Halon 1301 annually, of which 158 pounds
was released above 30,000 feet.  While EPA is awaiting the
results of the ODP calculations of CF3I, it is unlikely that such
low emissions at high altitude will pose a significant threat to
the ozone layer.
                  Interest in this agent is very high because it
may
constitute a drop-in replacement to Halon 1301 on a weight and
volume basis.  Initial tests have shown its weight equivalence
for fire extinguishment to be 1.36, and its volume equivalence to
be 1.0, while for explosion inertion it is 1.42 and 1.04
respectively.  The research community is continuing to qualify
the properties of this agent, including its materials
compatibility, its storage stability and its effectiveness. 
While the manufacturer's SNAP submission only requests listing in
normally unoccupied areas, preliminary cardiosensitization data
received by the Agency indicate that CF3I has a NOAEL of 0.2 per
cent and a LOAEL of 0.4 per cent, and thus this agent would not
suitably for use in normally occupied areas.
                                    (3)      Gelled Halocarbon/Dry
Chemical
                                             Suspension 
         Gelled Halocarbon/Dry Chemical Suspension is proposed
acceptable as a Halon 1301 substitute in normally unoccupied
areas.  Any employee who could possibly be in the area must be
able to escape within 30 seconds.  The employer shall assure that
no unprotected employees enter the area during agent discharge.  
         The manufacturer is proposing to blend either of two
halocarbons (HFC-125 or HFC-134a) with either ammonium
polyphosphate (which is not corrosive) or monoammonium phosphate
(which is corrosive on hard surfaces).  An initial assessment of
inhalation toxicology of fine particulates indicates that some
risk exists of inhalation exposure when the particles are below a
certain size compared to the mass per cubic meter in air. 
Particle sizes less than 10 to 15 microns and a mass above the
ACGIH nuisance dust levels raise concerns which need to be
further studied.  In a total flooding application, the exposure
levels may be of concern.  In addition, because the discharge of
powders obscures vision, evacuation could be impeded.  EPA is
asking manufacturers of total flooding systems using powdered
aerosols to submit to the Agency a review of the medical
implications of inhaling atmospheres flooded with fine powder
particulates.  While the manufacturer requested a SNAP listing
for unoccupied areas only, EPA would not consider its use in
occupied areas until the requested peer review is complete. 
Meanwhile, EPA is finding this technology acceptable for use in
normally unoccupied areas.
         For further discussion of this agent, including a review
of
particle size distributions, see the listing under "Streaming
Agents - Acceptable."
                                    (4)      Inert Gas/Powdered
Aerosol Blend
         Inert Gas/Powdered Aerosol Blend is acceptable as a Halon
1301 substitute in normally unoccupied areas.  In areas where
personnel could possibly be present, as in a cargo area, the
employer shall provide a pre-discharge employee alarm capable of
being perceived above ambient light or noise levels for alerting
employees before system discharge.  The pre-discharge alarm shall
provide employees time to safely exit the discharge area prior to
system discharge.  
         This alternative agent is formulated from a mixture of dry
powders pressed together into pill form.  Upon exposure to heat
from a fire, a pyrotechnic charge initiates a series of
exothermic, gas-producing reactions composed mainly of a mixture
of nitrogen, carbon dioxide and water vapor, with small amounts
of carbon monoxide, nitrous oxide, nitrogen dioxide, and solid
residues.  The oxygen level in the room is largely depleted, thus
extinguishing the fire. 
         The manufacturer has proposed this technology for use in
normally unoccupied areas only, such as engine nacelles and
engine compartments, aircraft dry bay areas and unoccupied cargo
areas.  Comparing agents alone, deployment of 2.0 pounds of this
agent at 400oF has an equivalent fire suppression effectiveness
to 1.0 pound of Halon 1301 at 70oF.
         This agent has no ODP. The carbon dioxide generated in the
combustion of this agent has a GWP of 1.
                  2.       Proposed Acceptable Subject to Narrowed
Use Limits
                           a.       Total Flooding Agents
                                    (1)      C3F8
         C3F8 is proposed acceptable as a Halon 1301 substitute
where
other alternatives are not technically feasible due to
performance or safety requirements: a) due to their physical or
chemical properties or b) where human exposure to the agents may
approach cardiosensitization levels or result in other
unacceptable health effects under normal operating conditions. 
This agent is subject to the use conditions stipulated for all
total flooding agents, that is:
                 Where egress from an area cannot be
accomplished within
one minute, the employer shall not use this agent in
concentrations exceeding its NOAEL.
                 Where egress takes longer than 30 seconds
but less than
one minute, the employer shall not use the agent in a
concentration greater than its LOAEL.
                 Agent concentrations greater than the LOAEL
are only
permitted in areas not normally occupied by employees provided
that any employee in the area can escape within 30 seconds.  The
employer shall assure that no unprotected employees enter the
area during agent discharge.  
         Cup burner tests in heptane indicate that C3F8 can
extinguish
fires in a total flood application at concentrations of 7.30 per
cent and therefore has a design concentration of 8.8 per cent. 
The cardiotoxic NOAEL of 30 per cent for this agent is well above
its extinguishment concentration; therefore, it is safe for use
in occupied areas.  This agent has a weight equivalence of two-
to-one by weight compared to Halon 1301.
         Using agents in high concentrations poses a risk of
asphyxiation by displacing oxygen.  With an ambient oxygen level
of 21 per cent, a design concentration of 22.6 per cent may
reduce oxygen levels to approximately 16 per cent, the minimum
level considered to be required to prevent impaired judgement or
other physiological effects.  Thus, the oxygen level resulting
from discharge of this agent must be at least 16 per cent.
         This agent has an atmospheric lifetime of 3,200 years and
a
100-year GWP of 6,100.  Due to the long atmospheric lifetime of
C3F8, the Agency is finding this chemical acceptable only in those
limited instances where no other alternative is technically
feasible due to performance or safety requirements.  In most
total flooding applications, the Agency believes that
alternatives to C3F8 exist.  EPA intends that users select C3F8 out
of need and that this agent be used as the agent of last resort. 
Thus, a user must determine that the requirements of the specific
end-use preclude use of other available alternatives.
         Users must observe the limitations on C3F8 acceptability
by
undertaking the following measures:  (i) conduct an evaluation of
foreseeable conditions of end use; (ii) determine that human
exposure to the other alternative extinguishing agents may
approach or result in cardiosensitization or other unacceptable
toxicity effects under normal operating conditions; and (iii)
determine that the physical or chemical properties or other
technical constraints of the other available agents preclude
their use.
         EPA recommends that users minimize unnecessary emissions
of
this agent by limiting testing of C3F8 to that which is essential
to meet safety or performance requirements; recovering C3F8 from
the fire protection system in conjunction with testing or
servicing; and destroying or recycling C3F8 for later use.  EPA
encourages manufacturers to develop aggressive product
stewardship programs to help users avoid such unnecessary
emissions.
                                    (2)      Sulfur Hexafluoride
(SF6)
         SF6 is acceptable for use as a discharge test agent in
military uses only.  Sulfur Hexafluoride is a nonflammable,
nontoxic gas which is colorless and odorless.  With a density of
approximately five times that of air, it is one of the heaviest
known gases.  SF6 is relatively inert, and has an atmospheric
lifetime of 3,200 years, with a 100-year, 500-year, and 1,000-
year GWP of 16,100, 26,110 and 32,803 respectively.
         This agent has been developed by the U.S. Navy as a test
gas
simulant in place of halon in new halon total flooding systems on
ships which have been under construction prior to identification
and qualification of substitute agents.  Halon systems are no
longer included in designs for new ships. The Navy estimates its
annual usage to be less than 10,000 pounds annually, decreasing
over time.  Thus, the Agency believes that the quantities
involved are not significant.
         While SF6 is not currently used in the commercial sector
and
new halon systems are rarely installed, EPA is proposing a
narrowed use limit to ensure that emissions of this agent remain
minimal.  The NFPA 12a and NFPA 2001 standards recommend that
halon or other total flooding gases not be used in discharge
testing, but that alternative methods of ensuring enclosure and
piping integrity and system functioning be used.   Alternative
methods can often be used, such as the "door fan" test for
enclosure integrity, UL 1058 testing to ensure system
functioning, pneumatic test of installed piping, and a "puff"
test to ensure against internal blockages in the piping network. 
These stringent design and testing requirements have largely
obviated the need to perform a discharge test for total flood
systems containing either Halon 1301 or a substitute agent.
                  3.       Proposed Unacceptable
                           a.       Total Flooding
                                    (1)      HFC-32
         HFC-32 is proposed unacceptable as a total flooding agent.
 
HFC-32 has been determined to be flammable, with a large
flammability range, and is therefore inappropriate as a halon
substitute when used as a pure agent.  This agent was proposed
acceptable in the first SNAP proposed rulemaking (58 FR 28093,
May 12, 1993) but public comment received indicated agreement
about the flammability characteristics of this agent.  EPA is not
aware of any interest in commercializing this agent as a fire
suppression agent.
IV.  Executive Order 12866
         Under Executive Order 12866, [58 FR 51735; October 4,
1993]
the Agency must determine whether the regulatory action is
"significant" and therefore subject to OMB review and the
requirements of the Executive Order.  The Order defines
"significant regulatory action" as one that is lifely to result
in a rule that may:  (1)  have an annual effect on the economy of
$100 million or more or adversely affect in a material way the
economy, a sector of the economy, productivity, competition,
jobs, the environment, public health or safety, or State, local,
or tribal governments or communities; (2) create a serious
inconsistency or otherwise interfere with an action taken or
planned by another agency; (3) materially alter the budgetary
impact of entitlement, grants, user fees, or loan programs or the
rights and obligations of recipients thereof; or (4) raise novel
legal or policy issues arising out of legal mandates, the
President's priorities, or the principles set forth in the
Executive Order."
         It has been determined that this rule is not a
"significant
regulatory action" under the terms of Executive Order 12866 and
is therefore not subject to OMB review.
V.       Additional Information
         Contact the Stratospheric Protection Hotline at 1-800-296-
1996, Monday-Friday, between the hours of 10:00 a.m. and 4:00
p.m. (EST).  
         For more information on the Agency's process for
administering the SNAP program or criteria for evaluation of
substitutes, refer to the SNAP final rulemaking published in the
Federal Register on March 18, 1994 (59 FR 13044).  Federal
Register notices can be ordered from the Government Printing
Office Order Desk (202) 783-3238; the citation is the date of
publication.  Notices and rulemaking under the SNAP program can
also be retrieved electronically from EPA's 

Protection of Stratospheric Ozone                                  
                                                 
Page 32 of 42
Technology Transfer Network (TTN), Clean Air Act Amendment
Bulletin Board.  The access number for users with a 1200 or 2400
bps modem is (919) 541-5742.  For users with a 9600 bps modem the
access number is (919) 541-1447.  For assistance in accessing
this service, call (919) 541-5384 during normal business hours
(EST).
List of Subjects of 40 CFR Part 9
         Environmental Protection, Reporting and Recordkeeping
Requirements.
List of Subjects in 40 CFR Part 82
         Environmental Protection, Administrative Practice and
Procedure, Air Pollution Control, Reporting and Recordkeeping
Requirments.

Date:  ______________________


_____________________________
Carol M. Browner,
Administrator

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