Protection of Stratospheric Ozone

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Part IV

Environmental Protection Agency

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40 CFR Part 82

Protection of Stratospheric Ozone; Proposed Rule

Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[FRL-5827-2]

RIN 2060-AG12

Protection of Stratospheric Ozone

AGENCY: Environmental Protection Agency.

ACTION: Notice of proposed rulemaking.

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SUMMARY: This action proposes restrictions or prohibitions on

substitutes for ozone depleting substances (ODSs) under the U.S.

Environmental Protection Agency's (EPA) Significant New Alternatives

Policy (SNAP) program. SNAP implements section 612 of the amended Clean

Air Act of 1990, which requires EPA to evaluate 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 substitutes

posing other environmental problems.

On March 18, 1994, EPA promulgated a final rulemaking setting forth

its plan for administering the SNAP program, and issued decisions on

the acceptability and unacceptability of a number of 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.

DATES: Written comments or data provided in response to this document

must be submitted by June 20, 1997.

ing 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.

DATES: Written comments or data provided in response to this document

must be submitted by June 20, 1997.

ADDRESSES: Written comments and data should be sent to Docket A-91-42,

Central Docket Section, South Conference Room 4, U.S. Environmental

Protection Agency, 401 M Street, SW., Washington, DC 20460. The docket

may be inspected between 8:00 a.m. and 4:00 p.m. on weekdays. Telephone

(202) 260-7549; fax (202) 260-4400. As provided in 40 CFR part 2, a

reasonable fee may be charged for photocopying. To expedite review, a

second copy of the comments should be sent to Carol Weisner,

Stratospheric Protection Division, Office of Atmospheric Programs, U.S.

EPA, 401 M Street, SW., 6205-J, Washington, DC 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

document. 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: Carol Weisner at (202) 233-9193 or fax

(202) 233-9665, Substitutes Analysis and Review Branch, Stratospheric

Protection Division, Office of Atmospheric Programs, Office of Air and

Radiation (6205-J), Washington, DC 20460. Overnight or courier

deliveries should be sent to our 501-3rd Street, NW, Washington, DC

20001 location.

SUPPLEMENTARY INFORMATION:

I. Overview of This Action

This action is divided into six 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. Administrative Requirements

V. Additional Information

II. Section 612 Program

r 501-3rd Street, NW, Washington, DC

20001 location.

SUPPLEMENTARY INFORMATION:

I. Overview of This Action

This action is divided into six 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. Administrative Requirements

V. Additional Information

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 six months

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 six 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

y 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 document.

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. Fully acceptable substitutes (i.e. no

restrictions) can be used 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

wed use limits;

unacceptable; and pending. Fully acceptable substitutes (i.e. no

restrictions) can be used 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 certain 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

able

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 adds 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 of acceptability in the Federal Register.

Parts A. through F. below present a detailed discussion of the

proposed substitute listing determinations by major use sector. Tables

summarizing listing decisions in this Notice of Proposed Rulemaking are

in Appendix E. The comments contained in Appendix E to Subpart G of 40

CFR part 82 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 application of

these substitutes

ditional 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 application 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--Class I

1. Acceptable Subject to Use Conditions. a. CFC-12 Automobile and

Non-automobile Motor Vehicle Air Conditioners, Retrofit and New (1)

Notification Requirements for Existing Refrigerants.

In previous rulemakings, EPA has imposed conditions on the use of

MVAC refrigerants, including the requirement that they be used with

unique fittings and that vehicles be labeled when retrofitted to a new

refrigerant. In addition, new refrigerants must be submitted with

designs for fittings, and samples of both fittings and labels. EPA now

proposes to apply these submission requirements to the following

existing refrigerants: HFC-134a, FRIGC, Freezone, Ikon, R-406A, GHG-X4,

Hot Shot, GHG-HP, and Freeze-12, each of which was previously listed as

acceptable subject to use conditions. In accordance with the

requirements for new refrigerants, EPA proposes that the manufacturers

must submit, within 30 days of the effective date of the final rule

resulting from this NPRM:

Designs for service ports and hose connections, including

both high-side and low-side fittings;

Sample fittings of each type;

Sample labels, printed in the unique color chosen by the

manufacturer

ditions. In accordance with the

requirements for new refrigerants, EPA proposes that the manufacturers

must submit, within 30 days of the effective date of the final rule

resulting from this NPRM:

Designs for service ports and hose connections, including

both high-side and low-side fittings;

Sample fittings of each type;

Sample labels, printed in the unique color chosen by the

manufacturer.

EPA will review the fittings and test for cross-connections between

the new fitting and existing fittings for other refrigerants. At the

same time, EPA will compare the background color of the sample label to

those of other refrigerants. If the fittings are unique and cannot be

mechanically cross-threaded, and the label color is unique to that

refrigerant, EPA will issue a letter to the manufacturer confirming

that the fittings and labels meet the use conditions. This confirmation

letter will be sent within 30 days of receipt of the submission. EPA

will then update a package of materials containing specifications for

existing fittings. This package will be provided to manufacturers of

new refrigerants and others who request it, to lower the risk of

duplicating fittings already in use.

If the fittings or the label color are not, in fact, unique, EPA

will issue a letter to the manufacturer indicating so. Continued use of

the refrigerant with the non-unique fittings will constitute a

violation of the unique fittings use condition.

EPA does not anticipate that these provisions will affect the

majority of the existing refrigerants because the manufacturers have

already submitted designs and sample labels and fittings for review.

However, it is necessary to formalize these submission requirements to

level the playing field and ensure that EPA has official submissions on

which to base future actions. For example, EPA will rely on designs and

samples to determine whether the submitted versions are actually being

used on cars

use the manufacturers have

already submitted designs and sample labels and fittings for review.

However, it is necessary to formalize these submission requirements to

level the playing field and ensure that EPA has official submissions on

which to base future actions. For example, EPA will rely on designs and

samples to determine whether the submitted versions are actually being

used on cars. Similarly, EPA will rely on the submissions to determine

whether a given fitting satisfies the uniqueness criteria proposed

below.

(2) Criteria for Uniqueness of Fittings. In previous rulemakings,

EPA has relied on refrigerant manufacturers to design unique fittings

with no further guidance. In this NPRM, EPA clarifies minimum criteria

for uniqueness. EPA proposes that all fittings for alternative

refrigerants must meet the following requirements:

High-side screw-on fittings for each refrigerant must

differ from high-side screw-on fittings for all other refrigerants,

including CFC-12;

Low-side screw-on fittings for each refrigerant must

differ from low-side screw-on fittings for all other refrigerants,

including CFC-12;

High-side screw-on fittings for a given refrigerant must

differ from low-side screw-on fittings for that refrigerant, to protect

against connecting a low-pressure system to a high-pressure one;

High-side screw-on fittings for each alternative

refrigerant must differ from low-side screw-on fittings for CFC-12;

High-side quick-connect fittings for each refrigerant must

differ from high-side quick-connect fittings for all other

refrigerants, including CFC-12;

Low-side quick-connect fittings for each refrigerant must

differ from low-side quick-connect fittings for all other refrigerants,

including CFC-12;

High-side quick-connect fittings for a given refrigerant

must differ from low-side quick-connect fittings for that refrigerant,

to protect against connecting a low-pressure system to a high-pressure

one;

For each type of container, the fitting for each

refrigerant must differ

or each refrigerant must

differ from low-side quick-connect fittings for all other refrigerants,

including CFC-12;

High-side quick-connect fittings for a given refrigerant

must differ from low-side quick-connect fittings for that refrigerant,

to protect against connecting a low-pressure system to a high-pressure

one;

For each type of container, the fitting for each

refrigerant must differ from the fitting for that type of container for

all other refrigerants, including CFC-12.

For screw-on fittings, EPA proposes that ``differ'' means that

either the diameter must differ by at least \1/16\ inch or the thread

direction must be reversed (i.e. right-handed vs. left-handed). Simply

changing the thread pitch is not sufficient. An additional requirement

for screw-on fittings, and the essential one for quick-connect

fittings, is that a person using normal force and normal tools

(including wrenches) must not be able to cross-connect fittings.

Following are some examples:

A \3/8\ (\6/16\) inch outside diameter screw-on fitting

with a right-hand thread differs from a \5/16\ inch outside diameter

screw-on fitting with a right-hand thread;

A \3/8\ inch outside diameter screw-on fitting with a

left-hand thread differs from a \3/8\ inch outside diameter screw-on

fitting with a right-hand thread;

A \3/8\ inch outside diameter screw-on fitting with a

right-hand thread pitch of 18 threads/inch does not differ from a \3/8\

inch outside screw-on diameter fitting with a right-hand thread pitch

of 24 threads/inch;

A quick-connect fitting differs from another quick-connect

fitting if all combinations of the same type male and female parts

(high, low, small can, 30-lb. cylinder) will not connect using normal

tools.

eter screw-on fitting with a

right-hand thread pitch of 18 threads/inch does not differ from a \3/8\

inch outside screw-on diameter fitting with a right-hand thread pitch

of 24 threads/inch;

A quick-connect fitting differs from another quick-connect

fitting if all combinations of the same type male and female parts

(high, low, small can, 30-lb. cylinder) will not connect using normal

tools.

(i) All previously listed refrigerants and all future refrigerants.

For refrigerants previously listed as acceptable subject to use

conditions, and for refrigerants submitted in the future, the use

conditions in force for retrofitted systems are proposed to apply to

new vehicles. In addition, the criteria for uniqueness of fittings

discussed above are proposed to apply, and all labels must meet UL

Standard 969-1995.

Since only HFC-134a is currently being used in new cars, the use

conditions were originally worded in such a way that a reasonable

interpretation would exclude their applicability to new cars. This

proposal extends the unique fittings and labels requirements to new

cars. EPA does not anticipate that this clarification will result in

any additional burden, since all new cars already use HFC-134a fittings

and labels. However, EPA invites comment on this proposal. Note that

the use conditions above replace only the fittings, labeling, and

``top-off'' conditions applicable to previously listed refrigerants.

Other conditions, such as the requirement to replace existing hoses

with barrier hoses, still apply to various refrigerants as listed in

the original rule.

In addition, as explained above, EPA believes it is necessary to

provide criteria for the uniqueness of fittings. This use condition

will apply these criteria formally to existing refrigerants. Finally,

the UL standard relates to permanence of labels, and is already part of

the applicable Society of Automotive Engineers (SAE) standard.

to various refrigerants as listed in

the original rule.

In addition, as explained above, EPA believes it is necessary to

provide criteria for the uniqueness of fittings. This use condition

will apply these criteria formally to existing refrigerants. Finally,

the UL standard relates to permanence of labels, and is already part of

the applicable Society of Automotive Engineers (SAE) standard.

(ii) HFC-134a, FRIGC FR-12, Freezone, Ikon, R-406A, GHG-X4, Hot

Shot, GHG-HP, and Freeze-12. For these refrigerants, all of which have

previously been found acceptable subject to use conditions, the

submission requirements discussed above are proposed to apply.

As discussed above, EPA believes that applying these requirements

formally will level the playing field between existing refrigerants and

new submissions. In addition, formal submissions of designs and sample

labels and fittings will allow EPA to monitor compliance with the other

use conditions.

2. Unacceptable Substitutes. a. NARM-502.

NARM-502, which consists of HCFC-22, HFC-23, and HFC-152a, is

proposed unacceptable as a substitute for R-502 in all new and

retrofitted end-uses.

HFC-23 has a lifetime of 250 years, and its 100-year global warming

potential (GWP) is 11,700. Both of these characteristics are

considerably higher than other HFCS and HCFCS. Numerous other

acceptable R-502 substitutes do not contain such high global warming

components. The Climate Change Action Plan directs EPA to reduce the

use of high global warming gases. Therefore, the use of this blend as

an R-502 substitute is proposed unacceptable.

b. NARM-12. NARM-12, which consists of HCFC-22, HFC-23, and HFC-

152a, is proposed unacceptable as a substitute for CFC-12 in all new

and retrofitted end-uses.

HFC-23 has a lifetime of 250 years, and its 100-year GWP is 11,700.

Both of these characteristics are considerably higher than other HFCs

and HCFCs. Numerous other acceptable R-502 substitutes do not contain

such high global warming components

12. NARM-12, which consists of HCFC-22, HFC-23, and HFC-

152a, is proposed unacceptable as a substitute for CFC-12 in all new

and retrofitted end-uses.

HFC-23 has a lifetime of 250 years, and its 100-year GWP is 11,700.

Both of these characteristics are considerably higher than other HFCs

and HCFCs. Numerous other acceptable R-502 substitutes do not contain

such high global warming components. The Climate Change Action Plan

directs EPA to reduce the use of high global warming gases. Therefore,

the use of this blend as an R-502 substitute is proposed unacceptable.

B. Refrigeration and Air Conditioning--Class II

1. Unacceptable Substitutes. a. NARM-22. NARM-22, which consists of

HCFC-22, HFC-23, and HFC-152a, is proposed unacceptable as a substitute

for HCFC-22 in all new and retrofitted end-uses.

NARM-22 contains HCFC-22. EPA does not believe it is appropriate to

replace a class II refrigerant with a blend containing a class II

refrigerant. Listing this blend as acceptable would be a barrier to a

smooth transition away from ozone-depleting refrigerants. Other

alternatives to HCFC-22 are already acceptable that do not contain any

ozone-depleting refrigerants.

In addition, HFC-23 has a lifetime of 250 years, and its 100-year

GWP is 11,700. Both of these characteristics are considerably higher

than other HFCs and HCFCs. Other acceptable HCFC-22 substitutes do not

contain such high global warming components. The 1993 Climate Change

Action Plan directs EPA to reduce the use of high global warming gases.

For this reason, and the fact that NARM-22 contains HCFC-22, the use of

this blend as an HCFC-22 substitute is proposed unacceptable.

C. Solvents Cleaning

1. Chlorobromomethane. Chlorobromomethane (CBM) has been used as a

fire suppressant and has the designation of Halon 1011. EPA has

received notification that it can also be used as a solvent and a

potential

se of high global warming gases.

For this reason, and the fact that NARM-22 contains HCFC-22, the use of

this blend as an HCFC-22 substitute is proposed unacceptable.

C. Solvents Cleaning

1. Chlorobromomethane. Chlorobromomethane (CBM) has been used as a

fire suppressant and has the designation of Halon 1011. EPA has

received notification that it can also be used as a solvent and a

potential

substitute for the ozone depleting solvents CFC-113, methyl chloroform

(MCF) and HCFC-141b. EPA received a SNAP submission requesting

consideration of CBM as an acceptable substitute for CFC-113 and MCF in

solvents cleaning of metals and electronics and in precision cleaning.

Analysis of the available toxicity data base for CBM raises significant

questions concerning its suitability as a solvent substitute for CFC-

113, or methyl chloroform, or HCFC-141b in metals cleaning, electronics

cleaning, and precision cleaning; and as a solvent agent in aerosols

and in adhesives, coatings and inks. In a subchronic study, at a dose

level of 500 parts per million (ppm), adverse effects were evident in

the livers of rats. At 1000 ppm, both guinea pigs and rabbits showed

decreased spermatogenesis, but no studies of reproductive or

developmental effects have been conducted. In addition, mutagenicity

tests with CBM in microorganisms yielded consistently positive results.

In mammalian systems, CBM induced sister chromatid exchanges. Thus the

mutagenic effects of CBM are unmistakable.

In 1989, EPA established a one day health advisory for water

contaminated with CBM at 50 ppm. A longer term health advisory was

established at 4.57 ppm for this compound in drinking water. OSHA

established an occupational Permissible Exposure Limit (PEL) of 200 ppm

based on the ``grandfathered'' Threshold Limit Value (TLV) which dates

back to 1961. This compound was not reviewed by OSHA in the 1989

proposed revision process

y health advisory for water

contaminated with CBM at 50 ppm. A longer term health advisory was

established at 4.57 ppm for this compound in drinking water. OSHA

established an occupational Permissible Exposure Limit (PEL) of 200 ppm

based on the ``grandfathered'' Threshold Limit Value (TLV) which dates

back to 1961. This compound was not reviewed by OSHA in the 1989

proposed revision process. In 1991, the only use noted for this

chemical by American Conference of Governmental Industrial Hygienists

(ACGIH) was as a liquid (streaming agent) fire suppressant. They

recommended an 8 hour TLV of 200 ppm consistent with the PEL. The

potential widespread use of CBM as a solvent substitute in the light of

its toxicity profile and significant data gaps imply a much lower

workplace limit. Based upon the lowest observed adverse effect level of

500 ppm in rats, the SNAP evaluation suggests a more appropriate

occupational exposure limit (OEL) to lie in the range of 2 and 5 ppm,

making this compound unsuitable for use as a solvent.

Recent authoritative research establishes an ozone depletion

potential (ODP) range for CBM of 0.17 to 0.28. Other alternatives exist

with much lower or no ODP and do not pose a comparable risk. As a

result of these recent ODP findings and the potential widespread use of

CBM in occupational settings unable to meet an OEL of 5 ppm, EPA

proposes this agent as unacceptable. Relevant reports and analyses on

these issues have been placed in the public docket for this SNAP

submission.

2. Acceptable Subject to Use Conditions. a. Metals Cleaning.

or no ODP and do not pose a comparable risk. As a

result of these recent ODP findings and the potential widespread use of

CBM in occupational settings unable to meet an OEL of 5 ppm, EPA

proposes this agent as unacceptable. Relevant reports and analyses on

these issues have been placed in the public docket for this SNAP

submission.

2. Acceptable Subject to Use Conditions. a. Metals Cleaning.

(1) HFC-4310mee.

HFC-4310mee is proposed as an acceptable substitute for CFC-113 and

methyl chloroform (MCF) in metals cleaning subject to a 200 ppm time-

weighted average workplace exposure standard and a 400 ppm workplace

exposure ceiling. This chemical does not deplete the ozone layer since

it does not contain chlorine or bromine. Review under the SNAP program

and the PMN program determined that a time-weighted average workplace

exposure standard of 200 ppm and a workplace exposure ceiling of 400

ppm would be adequately protective of human health and that companies

can meet these exposure limits using the types of equipment specified

in the product safety information provided by the chemical

manufacturer.

These workplace standards are designed to protect worker safety

until the Occupational Health and Safety Administration (OSHA) sets its

own standards under Pub. L. 91-596. The existence of the EPA standards

in no way bars OSHA from standard-setting under OSHA authorities as

defined in Public Law 91-596.

3. Unacceptable Substitutes. a. Metals Cleaning.

(1) Chlorobromomethane.

Chlorobromomethane is proposed unacceptable as a substitute for

CFC-113, methyl chloroform (MCF), and HCFC-141b in metals cleaning.

Recent authoritative research establishes an ozone depletion potential

(ODP) range for CBM of 0.17 to 0.28, and toxicity concerns exist based

on potential widespread use in occupational settings not meeting an

appropriate OEL of 5 ppm. Other alternatives exist with much lower ODP

and do not pose a comparable risk.

b. Electronics Cleaning.

l chloroform (MCF), and HCFC-141b in metals cleaning.

Recent authoritative research establishes an ozone depletion potential

(ODP) range for CBM of 0.17 to 0.28, and toxicity concerns exist based

on potential widespread use in occupational settings not meeting an

appropriate OEL of 5 ppm. Other alternatives exist with much lower ODP

and do not pose a comparable risk.

b. Electronics Cleaning.

(1) Chlorobromomethane.

Chlorobromomethane is proposed unacceptable as a substitute for

CFC-113, methyl chloroform, and HCFC-141b in electronics cleaning.

Recent authoritative research establishes an ODP range for CBM of 0.17

to .28, and toxicity concerns exist based on potential widespread use

in occupational settings not meeting an appropriate OEL of 5 ppm. Other

alternatives exist with much lower ODP and do not pose a comparable

risk. For example, hydrofluoroethers (HFE) and HFC-4310 mee do not

contain chlorine and have no ODP.

c. Precision Cleaning.

(1) Chlorobromomethane.

Chlorobromomethane is proposed unacceptable as a substitute for

CFC-113, MCF, and HCFC-141b in precision cleaning. Recent authoritative

research establishes an ODP range for CBM of 0.17 to 0.28, and toxicity

concerns exist based on potential widespread use in occupational

settings not meeting an appropriate OEL of 5 ppm. Other alternatives

exist with much lower ODP and do not pose a comparable risk. For

example, hydrofluoroethers (HFE) and HFC-4310 mee do not contain

chlorine and have no ODP.

D. Fire Suppression and Explosion Protection

1. Chlorobromomethane. As discussed in Solvents Cleaning above, CBM

has been used for fire suppression and explosion inertion, and is

designated Halon 1011. In the fire suppression and explosion protection

sector, Halon 1011 has been used as a total flooding agent, in lieu of

Halon 1301, for the purpose of preventing fires in the engine nacelles

of aircraft, principally in the military

ction

1. Chlorobromomethane. As discussed in Solvents Cleaning above, CBM

has been used for fire suppression and explosion inertion, and is

designated Halon 1011. In the fire suppression and explosion protection

sector, Halon 1011 has been used as a total flooding agent, in lieu of

Halon 1301, for the purpose of preventing fires in the engine nacelles

of aircraft, principally in the military. EPA understands the use of

Halon 1011 for this purpose has been extremely limited, and demand for

its future use is likely to be very small, given other alternatives.

Recent authoritative research establishes an ODP range for CBM of 0.17

to 0.28. Other alternatives exist for total flooding applications with

much lower or no ODP and do not pose a comparable risk. For example,

HFC-134a and HFC-227ea, as well as several inert gases, have no ODP. As

a result of these recent ODP findings, EPA proposes this agent

unacceptable as a substitute for Halon 1301.

2. Petition. EPA has received a Petition asking for reconsideration

of the wording of use conditions for PFCs and other long-lived gases.

The Petitioner believes that while it is EPA's stated intent that PFCs

be used as the agent of last resort when no other agent is acceptable

due to performance or safety requirements, the regulatory language is

unclear, potentially resulting in some users adopting PFCs

inappropriately. The regulatory language in the March 18, 1994,

Rulemaking (59 FR 13044, 13159) states the following:

C4F10 is 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.

13044, 13159) states the following:

C4F10 is 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 same language applies for use of other PFCs in this sector as

well.

EPA has discussed this language in rulemakings, letters and public

forums to ensure that the public understands that a PFC may be used if

no other commercially available agent will provide adequate protection

against the specific fire hazard given the technical or environmental

constraints of the application or if the use of other agents in the

application in question would exceed safe toxicity levels. For

halocarbons, cardiac sensitization is the primary endpoint of concern,

and for inert gases, hypoxia is the relevant endpoint. The SNAP

rulemaking describes the concentrations at which each agent can be

safely used.

The Petitioner suggests the following changes to the use conditions

for long-lived gases to allay confusion:

PFCs or other long-lived gases may only be used ``* * * (1) when

physical or chemical properties necessitate their use, or (2) when

the use of another SNAP accepted alternative would result in

exposures beyond its applicable use conditions (e.g., below the

minimum O2 content, egress times greater than 30 seconds

with design concentrations greater than LOAEL,) or (3) when the use

of other SNAP accepted alternatives would permanently impair the

health of those in the discharge area.

icable use

conditions or in other unacceptable health effects under normal

operating conditions.

The Petitioner did not make a cogent case for changing the phrase

``or result in other unacceptable health effects under normal operating

conditions'' and thus EPA rejects suggested changes to that phrase at

this time.

3. 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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions.

See the preceding discussion of the changes made to the use

condition on this agent.

(2) C4F10.

C4F10 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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions.

See the preceding dicussion of the changes made to the use

condition on this agent.

(3) HFC-236fa.

HFC-236fa is proposed acceptable as a Halon 1301 substitute when

manufactured using any process that does not convert

perfluoroisobutylene (PFIB) directly to HFC-236fa in a single step.

HFC-236fa may be used in explosion suppression and explosion inertion

applications, and may be used in fire suppression applications where

other non-PFC agents or 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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions

lications, and may be used in fire suppression applications where

other non-PFC agents or 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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions.

In the event of the development of acceptable alternatives which

EPA finds should not only replace Halon 1301 and HFC-236a in new

systems, EPA may grandfather existing uses but only to the extent

warranted by cost and timing as outlined in the original SNAP rule

discussion of grandfathering of unacceptable substitutes (59 FR 13057).

As discussed in the initial SNAP rulemaking (58 FR 13044, March 18,

1994), until OSHA establishes applicable workplace requirements, total

flooding agents are acceptable by the Agency for use in occupied areas

only under the following conditions:

1. Where egress from an area cannot be accomplished within one

minute, the employer shall not use the agent in concentrations

exceeding its NOAEL.

2. Where egress takes greater than 30 seconds but less than one

minute, the employer shall not use the agent in a concentration greater

than its LOAEL.

3. 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. These conditions will no longer apply once

OSHA establishes applicable workplace requirements.

The cardiac sensitization NOAEL of HFC-236fa is 10.0 per cent and

its LOAEL is 15 per cent. Cup burner tests with heptane indicate that

the extinguishment concentration for this agent is 5.3 per cent, thus

making its calculated design concentration 6.4 per cent

nter the

area during agent discharge. These conditions will no longer apply once

OSHA establishes applicable workplace requirements.

The cardiac sensitization NOAEL of HFC-236fa is 10.0 per cent and

its LOAEL is 15 per cent. Cup burner tests with heptane indicate that

the extinguishment concentration for this agent is 5.3 per cent, thus

making its calculated design concentration 6.4 per cent. Compared to

the cardiac sensitization values, these concentrations provide a

sufficient margin of safety for use in a normally occupied area.

In the March 18, 1994 final SNAP rule (58 FR 13044), EPA required

manufacturers to submit information on manufacturing processes to allow

an assessment of the risks posed to the general public and workers. EPA

clarified in that action that acceptability determinations made on the

basis of one company's submission would apply to the same chemical

produced by other manufacturers, obviating the need for duplicative

reporting requirements and review. However, manufacturers who believe a

given manufacturing process may pose additional risks beyond those

posed by other processes were required to alert EPA to that increased

hazard. The February 8, 1996 (61 FR 4736) Notice of Acceptability

specifically discussed the manufacturing process used in making HFC-

236fa, and that discussion is repeated below.

EPA is aware of several methods for manufacturing HFC-236fa,

including one that produces HFC-236fa directly from PFIB. PFIB is an

extremely toxic substance that could pose risks in very small

concentrations. Thus, EPA believes it is appropriate to distinguish

among the different methods for producing HFC-236fa. This acceptability

determination does not prohibit the manufacture of HFC-236fa directly

from PFIB. Rather, it finds

manufacturing HFC-236fa,

including one that produces HFC-236fa directly from PFIB. PFIB is an

extremely toxic substance that could pose risks in very small

concentrations. Thus, EPA believes it is appropriate to distinguish

among the different methods for producing HFC-236fa. This acceptability

determination does not prohibit the manufacture of HFC-236fa directly

from PFIB. Rather, it finds

acceptable the production of HFC-236fa in processes that do not convert

PFIB directly to HFC-236fa in a single step. If a manufacturer wishes

to produce HFC-236fa directly from PFIB, it must submit that process to

EPA for review under SNAP.

HFC-236fa can replace Halon 1301 at a ratio of 1.3 by weight and

1.5 by volume. Due to its relatively high boiling point of minus 1.6

degrees centigrade, this agent may not be suitable in a low temperature

environment. Its greatest potential appears to be in explosion

suppression and in applications benefited by a misting or liquid

discharge.

HFC-236fa does not deplete stratospheric ozone, however, it has an

atmospheric lifetime of 250 years and a 100-year GWP of 6300. Concerns

have been raised about this agent's potential atmospheric effects.

Thus, this agent should be handled so as to minimize unnecessary

emissions. Ways to minimize emissions include: Avoiding discharge

testing and training; providing a high level of maintenance to avoid

leaks and accidental discharges; recovering HFC-236fa from the fire

protection equipment in conjunction with testing or servicing; and

destroying HFC-236fa or recycling it for later use.

While HFC-236fa may be used without prejudice in explosion

protection applications, before users adopt it for general fire

suppression applications they must first ascertain that other non-PFC

substitutes or alternatives are not technically feasible due to

performance or safety requirements

ment in conjunction with testing or servicing; and

destroying HFC-236fa or recycling it for later use.

While HFC-236fa may be used without prejudice in explosion

protection applications, before users adopt it for general fire

suppression applications they must first ascertain that other non-PFC

substitutes or alternatives are not technically feasible due to

performance or safety requirements. That is, if a PFC is the only other

substitute that is technically feasible due to performance or safety

requirements, then this agent may be used in a general fire suppression

application. Potential users are expected to evaluate the technical

feasibility of other non-PFC substitutes or alternatives to determine

their adequacy to control the particular fire risk. Such assessment may

include an evaluation of the performance or functional effectiveness of

the non-PFC agents' effectiveness for the intended applications as well

as the risk to personnel potentially exposed to the agents. Similarly,

use of HFC-236fa due to toxicological concerns would be appropriate

where use of other non-PFC substitutes or alternatives would violate

the workplace safety use conditions set forth in the SNAP rulemakings

(58 FR 13044).

To assist users in their evaluation for general fire suppression

applications, EPA has prepared a list of vendors manufacturing halon

substitutes and alternatives. Although users are not required to report

the results of their investigation to EPA, companies must retain these

results in company files for future reference.

4. Proposed Acceptable Subject to Narrowed Use Limits. a. Streaming

Agents. (1) C6F14

C6F14 is proposed acceptable as a Halon 1211

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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions

Agents. (1) C6F14

C6F14 is proposed acceptable as a Halon 1211

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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions.

See the preceding discussion of the changes made to the use

condition on this agent.

(2) HFC-236fa.

HFC-236fa is acceptable as a Halon 1211 substitute in non-

residential applications when manufactured using any process that does

not convert perfluoroisobutylene (PFIB) directly to HFC-236fa in a

single step. The cardiac sensitization NOAEL of HFC-236fa is 10.0 per

cent and its LOAEL is 15 per cent. Cup burner tests with heptane

indicate that the extinguishment concentration for this agent is 5.3

per cent. Compared to Halon 1211, HFC-236fa has a weight equivalence of

1.1 to 1.5.

As discussed above, HFC-236fa does not deplete stratospheric ozone,

however, it has an atmospheric lifetime of 250 years and a 100-year GWP

of 6300. Concerns have been raised about this agent's potential

atmospheric effects. Thus, EPA recommends that users minimize

unnecessary emissions by limiting testing only to that which is

essential to meet safety or performance requirements; recovering HFC-

236fa from the fire protection equipment in conjunction with testing or

servicing; and destroying HFC-236fa or recycling it for later use. EPA

encourages manufacturers to develop aggressive product stewardship

programs to help users avoid such unnecessary emissions.

Further, this agent may not be used in residential applications,

e.g., by a private individual in applications in or around a permanent

or temporary household, during recreation, or for any personal use or

enjoyment. Use in watercraft or aircraft is excluded from the

definition of residential use.

develop aggressive product stewardship

programs to help users avoid such unnecessary emissions.

Further, this agent may not be used in residential applications,

e.g., by a private individual in applications in or around a permanent

or temporary household, during recreation, or for any personal use or

enjoyment. Use in watercraft or aircraft is excluded from the

definition of residential use.

(3) HFC-227ea.

HFC-227ea is acceptable as a Halon 1211 substitute in

nonresidential applications. The weight equivalence of this agent is

1.66 pounds per pound of Halon 1211. It has a cardiac sensitization

NOAEL of 9.0 per cent, and a LOAEL of 10.5% or greater. Its cup burner

extinguishment value is 5.8%.

This agent has no ozone depletion potential, a 100-year GWP of 2050

relative to carbon dioxide, and an atmospheric lifetime of 31 years. It

is already listed as acceptable for use in total flooding applications

as an alternative to Halon 1301 (March 18, 1994, 59 FR 13107).

b. 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

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions.

See the preceding discussion of the changes made to the use

condition on this agent.

(2) C4F10. C4F10 is

proposed acceptable as a Halon 1301 substitute where other alternatives

are not technically feasible due to performance or safety requirements:

o the agents may

result in failure to meet applicable use conditions or in other

unacceptable health effects under normal operating conditions.

See the preceding discussion of the changes made to the use

condition on this agent.

(2) C4F10. C4F10 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 result in failure to meet applicable use

conditions or in other unacceptable health effects under normal

operating conditions.

See the preceding discussion of the changes made to the use

condition on this agent.

(3) HFC-236fa. HFC-236fa is acceptable as a Halon 1301 substitute

when manufactured using any process that does not convert

perfluoroisobutylene (PFIB) directly to HFC-236fa in a single step.

HFC-236fa may be used in explosion suppression and explosion inertion

applications, and may be used in fire suppression applications where

other non-PFC agents or 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

result in failure to meet applicable use conditions or result in other

unacceptable health effects under normal operating conditions. Please

see the section on ``Proposed Acceptable Subject to Use Conditions''

for a complete discussion of this agent. This agent is subject to the

use conditions delineated in the above section.

5. Unacceptable Substitutes. a. Total Flooding Agents. (1)

Chlorobromomethane.

ilure to meet applicable use conditions or result in other

unacceptable health effects under normal operating conditions. Please

see the section on ``Proposed Acceptable Subject to Use Conditions''

for a complete discussion of this agent. This agent is subject to the

use conditions delineated in the above section.

5. Unacceptable Substitutes. a. Total Flooding Agents. (1)

Chlorobromomethane.

Chlorobromomethane is proposed unacceptable as a substitute for Halon

1301 in total flooding applications. Recent authoritative research

establishes an ODP range for CBM of 0.17 to 0.28. Other alternatives

exist for total flooding applications with lower or no ODP and do not

pose a comparable risk. For example, HFC-134a and HFC-227ea, as well as

several inert gases, have no ODP.

E. Aerosols

1. Chlorobromomethane. Chlorobromomethane (CBM) has been used as a

fire suppressant and has the designation of Halon 1011. EPA has

received notification that it can also be used as a solvent and a

potential substitute for the ozone depleting solvents CFC-113, methyl

chloroform (MCF) and HCFC-141b. EPA received a SNAP submission

requesting consideration of CBM as an acceptable substitute for CFC-113

and MCF in solvents cleaning of metals and electronics and in precision

cleaning. Analysis of the available toxicity data base for CBM raises

significant questions concerning its suitability as a solvent

substitute for CFC-113, or methyl chloroform, or HCFC-141b in metals

cleaning, electronics cleaning, and precision cleaning; and as a

solvent agent in aerosols and in adhesives, coatings and inks. In a

subchronic study, at a dose level of 500 ppm, adverse effects were

evident in the livers of rats. At 1000 ppm, both guinea pigs and

rabbits showed decreased spermatogenesis, but no studies of

reproductive or developmental effects have been conducted. In addition,

mutagenicity tests with CBM in microorganisms yielded consistently

positive results. In mammalian systems, CBM induced sister chromatid

exchanges

y, at a dose level of 500 ppm, adverse effects were

evident in the livers of rats. At 1000 ppm, both guinea pigs and

rabbits showed decreased spermatogenesis, but no studies of

reproductive or developmental effects have been conducted. In addition,

mutagenicity tests with CBM in microorganisms yielded consistently

positive results. In mammalian systems, CBM induced sister chromatid

exchanges. Thus the mutagenic effects of CBM are unmistakable.