EPA-600 /R-9 5-150 a
September 1995
LOW OZONE-DEPLETING HALOCARBONS AS TOTAL-FLOOD AGENTS:
VOLUME 1—CANDIDATE SURVEY
by
Stephanie R. Skaggs, Robert E. Tapscott, Jonathan S, Nimitz, and Ted A. Moore
Center for Global Environmental Technologies
New Mexico Engineering Research Institute
The University of New Mexico
Albuquerque, New Mexico 87131 -1376
Cooperative Agreement CR-817774-01-0
Project Officer
N. Dean Smith
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Prepared for:
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
WASHINGTON, DC 20460
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before complt
1. REPORT NO. 2.
EP A-600/R-95-150a
3
4. TITLE AND SUBTITLE
Low Ozone-Depleting Halocarbons as Total-Flood
Agents: Volume l-~ Candidate Survey
5. REPORT DATE
September 1995
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
S. R. Skagga, R. E. Tapscott, J. S. Nimitz, and
T. A. Moore
8. PERFORMING ORGANIZATION REPORT NO.
NMERI OC 9414
9. PERFORMING ORGANIZATION NAME AND ADDRESS
The University of New Mexico
New Mexico Engineering Research Institute
Albuquerque, New Mexico 87131-1376
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
CR-817774-01-0
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 10/90 - 3/93
14. SPONSORING AGENCY CODE
EPA/600/13
15.supplementary notes project officer is N. Dean Smith, Mail Drop 62B, 919/541"
2708. Volume 2 is "Laboratory-scale Fire Suppression and Explosion Prevention
Testing."
16. abstract rj-jie vojume describes an effort to identify chemical fire protection and ex-
plosion prevention agents which may replace the ozone-depleting agent Halon-1301
(Ci'3Br). Halon-1301 is used in total-flood fire protection systems where the agent is
released as a gas into an enclosed space. Available information from the open litera-
ture and from industry contacts was collected on approximately 650 halogenated hy-
drocarbons. Candidate agents surveyed included perfluorocarbons, hydrofluorocar—
bons, and hydrochlorofluorocarbons as well as selected hydrobromofluorocarbons,
fluoroiodocarbons, haloethers, and haloalkenes. On the basis of physical properties,
chemical stabilities, toxicities, availabilities, costs, materials compatibilities, fire
suppression capabilities, and environmental considerations, 29 chemicals are recom-
mended for laboratory-scale testing as potential fire suppression and explosion pre-
vention agents.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Halohydrocarbons
Fire Protection
Explosion Proofing
Surveys
Ozone
Ethers
Alkene Compounds
Pollution Prevention
Stationary Sources
Total- Flooding
13 B
07 C
131 -
14 R
07B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report}
Unclassified
21. NO. OF PAGES
103
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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FOREWORD
The U. S. Environmental Protection Agency is charged by Congress with pro-
tecting the Nation's land, air, and water resources. Under a mandate of national
environmental laws, the Agency strives to formulate and implement actions lead-
ing to a compatible balance between human activities and the ability of natural
systems to support and nurture life. To meet this mandate, EPA's research
program is providing data and technical support for solving environmental pro-
blems today and building a science knowledge base necessary to manage our eco-
logical resources wisely, understand how pollutants affect our health, and pre-
vent or reduce environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for
investigation of technological and management approaches for reducing risks
from threats to human health and the environment. The focus of the Laboratory's
research program is on methods for the prevention and control of pollution to air,
land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites and groundwater; and prevention and
control of indoor air pollution. The goal of this research effort is to catalyze
development and implementation of innovative, cost-effective environmental
technologies; develop scientific and engineering information needed by EPA to
support regulatory and policy decisions; and provide technical support and infor-
mation transfer to ensure effective implementation of environmental regulations
and strategies.
This publication has been produced as part of the Laboratory's strategic long-
term research plan. It is published and made available by EPA's Office of Re-
search and Development to assist the user community and to link researchers
with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
EPA REVIEW NOTICE
This report has been peer and administratively reviewed by the U.S. Environmental
Protection Agency, and approved for publication. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161.
i i
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ABSTRACT
Adequate protection of enclosed facilities against explosions and fires involving flammable gases or
streaming liquid fuels poses major safety challenges for the Alaskan North Slope petroleum industry. At present,
such facilities are protected by Halon 1301 total-flood fire suppression systems. However, because of its impact on
stratospheric ozone, the production of Halon 1301 was halted undeT international agreement on December 31,
1993. The U. S. Environmental Protection Agency* and the New Mexico Engineering Research Institute are
cooperating to investigate replacements for Halon 1301 in North Slope applications with low ozone-depleting
halocarbons. Initial work focused on perfluorocarbons, hydrofluorocarbons, and hydrochlorofluorocarbons;
however, serious tradeoffs existed for such candidates. Consequently, the EPA expanded the scope of work to
include other classes of halocarbons that were anticipated to have low ozone-depleting characteristics and superior
fire and explosion protection capabilities. This report describes the candidate survey and selection criteria for
Halon 1301 replacements to be used as total-flood fire and explosion protection agents for North Slope facilities.
Candidate agents investigated in this project included perfluorocaibons, hydrofluorocarbons, and
hydrochlorofluorocarbons as well as selected hydrobromofluorocarbons, fluoroiodocarbons, haloethers, and
haloalkenes.
This report (Volume 1) presents the selection criteria and analyses used to screen candidate total-flood fire
and explosion suppression agents and recommends candidates to be investigated in laboratory-scale testing. The
overall effort was divided into two parts. (1) nonbromine- or noniodine-containing chemicals (physical action
agents) and (2) bromine- and iodine-containing chemicals (chemical action agents). Approximately 50 physical
action agents were identified, and 40 chemical action agents were considered. The selection criteria used to
evaluate these candidates were physical properties, chemical stability, toxicity, availability and cost, materials
compatibility, cleanliness, environmental considerations, and regulatory concerns. Based on these selection
criteria, fewer than 20 physical action agents and 10 chemical action agents were recommended for laboratory-
scale testing. The results of the laboratory-scale tests on fire suppression (cup burner) and explosion protection
(explosion sphere) effectiveness are presented in a separate document (Volume 2). From the laboratoiy-scale
evaluation and pertinent regulatory considerations, a smaller number of candidates were selected to be evaluated at
field scale. Due to large quantity of material needed for field-scale evaluation, only candidates available in bulk
were investigated. This report provides recommendations about the potential of each candidate to serve as a Halon
1301 replacement agent for total-flood fire suppression and explosion prevention at the North Slope facilities.
* EPA's Air and Energy Engineering Research Laboratory, the initiator of this work, has been redesignated as the
Air Pollution Prevention and Control Division of EPA's National Risk Management Research Laboratory.
i i i
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CONTENTS
Abstract i i i
Tables v
Abbreviations and Symbols V i
Acknowledgments v ii i
1 Introduction 1
2 Physical Action Agents 4
Initial Chemical Selection 4
Selection Criteria 6
Physical Properties 7
Chemical Stability 9
Toxicity 10
Availability and Cost 24
Materials Compatibility 24
Cleanliness 26
Flame Suppression 27
Environmental Considerations 29
3 Chemical Action Agents 32
Initial Chemical Selection 32
Selection Criteria 32
Physical Properties 32
Toxicity 37
Availability and Cost 55
Environmental Considerations 55
4 Recommended Agents 58
Physical Action Agents 58
Chemical Action Agents 60
References 63
Appendices
A Definitive Rules for Naming and Numbering Haloalkanes 71
B Regulatory Concerns 76
C List of Chemical Suppliers 95
i v
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TABLES
Number Page
1. Second-Generation Chemical Classes 3
2. List of Physical Action Agents 5
3. Selected Physical Properties of Physical Action Agents 8
4. Halocaibons Being Investigated Under PAFTT 10
5. Toxicity of Physical Action Agents 13
6. Availability of Physical Action Agents 25
7. Atmospheric Lifetimes, ODPS, and GWPS of Physical Action Agents 30
8. List of Chemical Action Agents 33
9. Selected Physical Properties of Chemical Action Agents 35
10. Toxicity Summary of Hydrobromocarbons 39
11. Acute Lethality of Fluoroiodocarbons 44
12. Toxicity Summary of Halogenated Ethers 45
13. Acute Inhalation Toxicity of Several Halogenated Ethenes 51
14. Proposed Mutagenicity of Haloalkene Candidates 52
15. Acute Inhalation Toxicity of DCHFB in Various Species at Varying Times 53
16. Summary of Single Exposure of Rats to Perfluoroisobutylene 54
17. Proposed Candidate Availability and Cost 56
18. Candidate Group List of Physical Action Agents 59
19. Candidate Group List of Chemical Action Agents 62
B-l. Summary of Amendments to the Montreal Protocol, Passed June 1990 77
B-2. Annex C, Group II, Montreal Protocol as Amended in 1992 78
B-3. Comsumption Cuts Under Copenhagen Amendment 79
B-4. Chemicals Listed in Title VI of the Clean Air Act Amendments of 1990 82
B-5. Summary of Production Limits Under Title VI of the Clean Air Act Amendments of 1990 82
B-6. Environmental Concerns Under SNAP 84
B-7. Regulatory Summary of Physical Action Agents 91
B-8. Regulatory Summaiy of Chemical Action Agents 93
V
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ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS
ACGIH
— American Conference of Governmental Industrial Hygienisis
AD
— Approximate Dose
ASTM
— American Society for Testing and Materials
BFC
— Bromofluorocaibon
CAA
— Chemical Action Agent, also Clean Air Act
CAAA
— Clean Air Act Amendments of 1990
CEQ
— Council on Environmental Quality
CERCLA
— Comprehensive Environmental Response, Compensation, and Liability Act
CFC
~ Chlorofluorocarbon
CGET
~ Center for Global Environmental Technologies
CNS
- Central Nervous System
CWA
- Clean Water Act
DCHFB
-- Dichlorohexafluorobutene
ECc
~ Extinguishment Concentration of Candidate
ECr
-- Extinguishment Concentration of Reference Agent
EIS
— Environmental Impact Statement
EPA
— Environmental Protection Agency
EPCRA
~ Emergency Planning and Community Right-to-Know Act
FC
— Fluorocarbon (perfluorocarbon)
GVEf
— Gas Volume Effectiveness
GVEq
-- Gas Volume Equivalent
GWP
— Global Warming Potential
HARC
-- Halon Alternatives Research Corporation
IIBFC
— Hydrobromofluorocarbon
HCFC
— Hydrochlorofluorocarbon
HFC
— Hydrofluorocarbon
ICc
— Inciting Concentration of Candidate
ICr
~ Inerting Concentration of Reference Agent
IUPAC
- International Union of Pure and Applied Chemistry
LC
— Lethal Concentration
LD
— Liquid Density
LDC
— Liquid Density of Candidate
LDr
~ Liquid Density of Reference Agent
LLNL
— Lawrence Livermore National Laboratory
LOAEL
— Lowest observed adverse effect level
MWC
— Molecular Weight of Candidate
MWr
~ Molecular Weight of Reference Agent
NEPA
— National Environmental Policy Act
NIST
— National Institute of Standards and Technology
NMERI
~ New Mexico Engineering Research Institute
NOAEL
— No observ ed adverse effect level
ODC
— Ozone-Depleting Chemical
ODS
— Ozone-Depleting Substance
ODP
- Ozone-Depletion Potential
OSHA
— Occupational Safety and Health Administration
PAA
— Physical Action Agent
PAFTT
— Program for Alternative Fluorocarbon Toxicity Testing
(continued)
vi
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ABBREVIATIONS AND SYMBOLS (CONCLUDED)
PFIB — Perfluoroisobutylene
PMN — Premanufacture Notification
QSAR — Quantitative Structure-Activity Relationship
RCRA — Resource Conservation and Recovery Act
RTECS - Registry of Toxic Effects of Chemical Substances
SARA — Superfund Amendments and Reathorization Act
SDWA — Safe Drinking Water Act
SNAP — Significant New Alternatives Policy
SNUR — Significant New Use Regulation
SVEf — Storage Volume Effectiveness
SVEq — Storage Volume Equivalent
TLV - Threshold Limit Value
TSCA — Toxic Substances Control Act
WEf — Weight Effectiveness
WEq — Weight Equivalent
SYMBOLS
cm - centimeter
J ~ joule
kg — kilograms
L — liter
m — meter
mm — millimeter
N — newton
Pa — pascal
psi — pounds per square inch
sec ~ second
°C ~ degrees Celsius
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ACKNOWLEDGMENTS
This woik was sponsored in part by the U. S. Environmental Protection Agency. U. S. Coast Guard, and
the North Slope oil and gas producers.
vf ii
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SECTION 1
INTRODUCTION
Adequate protection of enclosed facilities against explosions and fires involving llanunable gases or
streaming liquid fuels poses major safety challenges for the Alaskan North Slope petroleum industry. At present,
such facilities are protected by Halon 1301 total-flood fire suppression systems. However, because of its impact on
stratospheric ozone, the availability of Halon 1301 has been substantially limited. In the absence of Halon 1301.
no proven method for adequate protection of North Slope and related facilities exists. The U.S. Environmental
Protection Agency (EPA) and the New Mexico Engineering Research Institute (NMERT) are cooperating to
investigate replacement of Halon 1301 in North Slope applications with low ozone-depleting halocarbons. This
effort was divided into two areas of emphasis: (1) physical action agents (PAA)—pcrfluorocarbons,
hydrofluorocarbons, and hydrochlorofluorocarbons—and (2) chemical action agents (CAA), i.e., other classes of
halocarbons that were anticipated to have low ozone-depleting characteristics and superior fire and explosion
protection capabilities—selected haloalkenes, haloethcrs. hydrobromofluorocarbons. and (luoroiodocarbons. This
report describes the initial effort undertaken to evaluate these other families of halocarbons as substitute total-flood
fire and explosion protection agents for North Slope petroleum production, handling, and transport facilities.
A typical requirement for total-flood agents is having a sufficiently low boiling point such that, when
released from the extinguisher system, the agent rapidly vaporizes in the enclosed space to provide three-
dimensional protection against fires and explosion. The chemicals investigated previously were selected to operate
in the same manner. Accordingly, chemicals were selected primarily based on boiling points since this is a
detectable first indication of the volatility of a chemical. To ensure that candidates would easily volatilize at
ambient conditions, a boiling point cutoff of less than or equal to 0 °C was established. All possible
perfluorocarbons (FCs), hydrofluorocarbons (HFCs), and hydrochlorofluorocarbons (HCFCs) were screened based
on this boiling point criterion to determine an initial list of candidate agents. This initial list of PA As was then
reduced, based on other selection criteria, resulting in a list of chemicals recommended for further investigation.
Of all the possible one- through eight-carbon halocarbons containing chlorine, fluorine, and hydrogen,
approximately 50 chemicals met the boiling point criteria (e.g., < 0 °C). Of these 50 candidates, fewer than 20
were available for purchase. The available chemicals were tested for flame suppression and inertion capabilities in
laboratory apparatuses. The laboratory-scale testing of these agents is documented in a report provided to the
EPA (1). Unfortunately, the testing revealed that approximately two to four times more replacement agent would
be required to provide the same fire and explosion prevention protection as Halon 1301. Consequently, other
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families of halocaibons should be investigated in search of candidates with superior fire suppression and inertion
capabilities. Many of the chemicals targeted for the current investigation have boiling points above 0 °C and,
therefore, may likely require an alternative method of dispensing the agent. Additional work will be required to
investigate the possibility of using a misting system to deliver higher boiling point halocarbons in a three-
dimensional, lotal-flooding capacity.
Halon replacements can be divided into two types depending on their mechanisms of fire extinguishment:
physical action agents (PA A) and chemical action agents (CAA). Assignment to a category does not imply that the
particular agent does not operate by both mechanisms, rather that one action appears to be the predominant mode
of extinguishment. Physical extinguishment can occur by a variety of mechanisms: vapor-phase heat absorption,
liquid-phase heat absorption, evaporative cooling, thermal dissociation, dilution of fuel and oxygen, and separation
of fuel and oxygen; however, vapor-phase heat absorption appears to be the most important for the PAA halon
replacements (FCs. HFCs, and HCFCs). These chemicals do not contain bromine or iodine, the two constituents
that impart chemical action (2). PAAs tend to have lower ozone-depletion potentials (ODPs) than CAAs because
of the absence of bromine. However, the PAAs previously evaluated required two to four times more agent to effect
extinguishment or prevent explosions compared to Halon 1301. Nonetheless, these PAA replacements may offer
much needed transitional protection during the period in which halons are being phased out of production but
before new, preferred substitutes are found and manufacturing facilities are established. Because of the extensive
time it takes to investigate new agents and technological approaches, the search was begun for superior methods to
protect people and property on the North Slope from the threat of fires and explosions. This search involved the
investigation of CAAs.
Chemical extinguishment occurs primarily by removal of combustion free-radicals (e.g., hydrogen and
oxygen atoms, and hydroxy] free radicals) that inhibit chain reaction mechanisms. With halocaibon agents,
significant free radical removal requires the presence of bromine or iodine. Free radical removal occurs through
the hydrogen bromide flame suppression cycle in the following reactions.
CBrF3 + H* -»• CF3* + HBr [1]
HBr + H* -> H2 + Br* 12]
Br* + Br* + M -> Br2 + M* [3]
BT2 + H* -» HBr + Br* [4|
In general, CAAs have high explosion protection and fire suppression capabilities. However, such agents
also tend to have higher toxicities, and bromine-containing compounds tend to have high ODPs. The only
bromine-containing chemicals likely to have an acceptable ODP (and also a low atmospheric lifetime and global-
warming potential [GWP]) are bromofluoroalkenes. hydrobromofluoroalkenes, and hydrobromofluorocarbons
2
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containing geminal dibromides. Some bromine-containing ethers could also have low atmospheric lifetimes. The
probable mechanism for atmospheric removal of bromine-containing ethers is thought to be rainout (removal of
chemicals in precipitation); however, it is uncertain whether this will be adequate to reduce the ODP of this type of
chemical to acceptable levels.
A need now exists for second-generation, chemically-acting replacement (halocarbon) agents that have
both low ODPs and high fire and explosion protection efficiencies. One emphasis of this work was to investigate
possible CAAs. Generally, highly effective halocarbon agents need the presence of bromine or iodine (2);
however, this increases the potential detrimental effects of these chemicals on the global environment. (NOTE:
Although chlorine also appears to provide some degree of chemical fire suppression through the reactions OH +
HQ -> CI + H2O and CI + HO2 -> HC1 + O2, the efficiency of the chemical flame inhibition reactions of chlorine
appears to be much less than that afforded by bromine or iodine.) Decreasing the tropospheric lifetime of
halocarbons is one means of reducing their impact on the environment. Several "new" mechanisms have been
identified to reduce tropospheric lifetimes while keeping the substituents—iodine or bromine—that allow chemical
action for fire extinguishment. Among the mechanisms that allow decreased tropospheric lifetimes are the
reaction of a carbon-carbon double bond with hydroxyl free radicals (alkenes), photolysis (alkencs, iodides, and
geminal dibromides), and rainout (polar molecules such as ethers).
Some of the chemical classes that exhibit the desired tropospheric removal processes are shown in
Table 1. Several of these classes have been shown to be highly effective in fire suppression testing. Also,
preliminary indications suggest that many of these compounds have near-zero ODPs, short atmospheric lifetimes,
and low G WPs. These indications need to be verified; however, fielding will require several years due to the
requirements for field and emissions testing, toxicity testing, shelf-life determination, assessment of compatibility
with engineering materials, and development of manufacturing capabilities.
TABLE 1. SECOND-GENERATION CHEMICAL CLASSES
Chemical family
Tropospheric destruction process
Hydrogen-containing geminal
dibromides
Reaction with hydroxyl free radicals
tropospheric photolysis
Fluoroiodocarbons
Tropospheric photolysis
Polar-substituent bromocarbons
Rainout
Bromofluoroalkenes
Reaction of double bond with hydroxyl free
radicals tropospheric photolysis
3
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SECTION 2
PHYSICAL ACTION AGENTS
INITIAL CHEMICAL SELECTION
The technical approach of Ihe effort reported herein was specifically tailored to address Halon 1301
replacements in total-flood applications for protection against explosion and fire hazards threatening North Slope
facilities. The approach of the candidate survey encompasses all facets of the problem, including physical
properties, chemical stability, toxicity, availability and cost, materials compatibility, cleanliness, fire suppression,
environmental considerations, and regulatory concerns.
Volatility determines the physical state of an agent when delivered (either gas or liquid) and thus defines
whether a chemical can be used as a total-flood or streaming agent. Since boiling point is an easy measure of
volatility, this property was used as the initial screening criterion to identify potential total-flood candidate agents.
The NMERI HALOCARBON DATABASE® (3) contains information on more than 650 halogcnated
hydrocarbons including all one- and two-carbon halocarbons and selected three- to eight-carbon halocarbons
containing hydrogen, fluorine, chlorine, bromine, and iodine. However, measured boiling points are available for
only approximately 50 percent of the halocarbons in the database. Therefore, an algorithm was developed using
Meissner's method to predict boiling point based on chemical structure, using molar refraction and McGowan's
parachor, both atomic additivitv properties of structure (4), The correlation coefficient (R2) for the algorithm is
0.95 with 321 degrees of freedom and a standard deviation of 30 °C Using both known and predicted boiling
points, all the chemicals in the database were screened. For initial screening, the upper cutoff used for known
boiling points was 0 °C and for the estimated boiling points was +20 °C (to allow for error in the predicted values).
The lower cutoff was -150 °C for known boiling points and -170 °C for estimated boiling points. This range of
boiling points was selected as a conservative screening criterion because chemicals with boiling points above
-20 °C might be delivered as liquids and may not disperse rapidly enough for use in total-flood applications. Gases
cool on expansion from a compressed cylinder, and this expansion may cool them below their boiling points,
causing the agents to condense and be delivered as liquids. For example, Halon 1211 (boiling point -4 °C) is
delivered as a liquid. Halon 1301 (boiling point -58 °C), on the other hand, is delivered as a gas. Also,
compounds with extremely low boiling points (below about -100 °C) will have very high vapor pressures at
ambient temperatures and may require heavy-duty, high-pressure containment systems.
The preliminary database survey identified 52 one-to-four-carbon FCs, HFCs, and HCFCs with boiling
points within the desired range; Table 2 lists the halocarbon numbers, formulas, boiling points, and Chemicals
Abstracts Services (CAS) numbers of these physical action candidates. Appendix A provides information on
4
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TABLE 2, LIST OF PHYSICAL ACTION AGENTS
Halocarbon no.
Formula
BP (°C) (literature values
accurate to ± 3 °C)
CAS no.
Halon 1301 (as reference)
CF3Br
-57
75-63-8
14
cf4
-129
75-73-0
22
chcif2
-41
75-45-6
23
chf3
-82
75-46-7
31
ch2cif
-9
593-70-4
32
ch2f2
-52
75-10-5
116
CF3CF3
-79
76-16-4
124
CHCIFCF3
-12
2837-89-0
124a
CHF2CCIF2
-10
354-25-6
125
chf2cf3
-49
354-33-6
134
chf2chf2
-20
359-35-3
134a
ch2fcf3
-27
811-97-2
142a
chcifch2f
15 (estimated value)
338-64-7
142b
ccif2ch3
-10
75-68-3
143a
ch3cf3
-48
420-46-2
152a
chf2ch3
-27
75-37-6
C216
cf2cf2cf2
-32
931-91-9
218
OF 3CF2CF3
-36
76-19-7
226ba
cf3ccifchf2
1 (estimated value)
51346-64-6
227ca
cf3cf2cf2h
-17
2252-84-8
227ea
cf3chfcf3
-15
431-89-0
C234
cf2cf2ch2
-12 (estimated value)
3899-71-6
235da
cf3chcichf2
10 (estimated value)
28103-66-4
235cc
ch2fcf2ccif2
10 (estimated value)
677-55-4
235ca
chf2cf2chcif
10 (estimated value)
679-99-2
235ba
chf2ccifchf2
10 (estimated value)
N/A
235eb
chf2chfccif2
10 (estimated value)
N/A
235ea
cf3chfchcif
10 (estimated value)
N/A
235bb
cf3ccifch2f
10 (estimated value)
N/A
236cb
ch2fcf2cf3
1
677-56-5
236fa
cf3ch2cf3
-1
690-39-1
244db
cf3chcich2f
19 (estimated value)
117970-90-8
244da
chf2chcichf2
19 (estimated value)
19041-2-2
244fb
ccif2ch2chf2
19 (estimated value)
2730-64-5
244bb
cf3ccifch3
19 (estimated value)
421-73-8
244ca
chf2cf2ch2ci
19 (estimated value)
679-85-6
244cb
ch2fcf2chcif
19 (estimated value)
67406-66-0
244ba
CHF2CCIFCH2F
19 (estimated value)
N/A
244ea
chf2chfchcif
19 (estimated value)
N/A
244eb
cf3chfch2ci
19 (estimated value)
N/A
244fa
cf3ch2chcif
19 (estimated value)
N/A
244ec
CCIFjCHFCH^
19 (estimated value)
N/A
245cb
cf3cf2ch3
-18
1814-88-6
245ea
chf2chfchf2
-27 (estimated value)
24270-66-4
245eb
cf3chfch2f
-27 (estimated value)
431-31-2
245ca
chf2cf2ch2f
-27 (estimated value)
679-86-7
254ea
chf2chfch2f
-17 (estimated value)
24270-68-6
254cb
chf2cf2ch3
-17 (estimated value)
40723-63-5
254eb
cf3chfch3
-17 (estimated value)
421-48-7
254fa
chf2ch2chf2
-17 (estimated value)
66794-30-7
254ca
ch2fcf2ch2f
-17 (estimated value)
813-75-2
3-1-10
C4F10
-5
355-25-9
C318
—-
-6
115-25-3
5
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halocarbon naming and numbering rules. This initial list of chemicals was deliberately kept somewhat broad to
allow for later screening based on other criteria discussed below.
Several halocarbons with boiling points between 0 °C and -150 °C were eliminated from consideration for
various reasons. Some were fully halogenated and contain chlorine and/or bromine. Such materials would have
unacccptably high ODPs and are therefore regulated under the Montreal Protocol; consequently, CFCs 12, 13, 115,
and bromofluorocaibon (BFC) 115B1 were eliminated from the list. Among other halocarbons eliminated were
(1) hydrobromofluorocarbons (HBFCs) 22BI, 124B1, and 124aBl because of high predicted or known ODPs and
(2) CFC-40 because of flammability and well-known toxicity concerns.
Nine HCFCs were eliminated from immediate consideration because they are experimentally unknown
chemicals and have not even been assigned CAS numbers. Although no information is available for these
chemicals, they have been given arbitrary NMERI numbers for inclusion in the database.
HFCs 32, 142b, 152a and probably all of the 254 isomers are flammable and could only be used as minor
components in blends. Generally, if hydrogen atoms constitute half or more of the substituents on a molecule, the
chemical is at risk of being flammable at some concentration in air. These flammable agents were left on the list
of PAAs for consideration if blends become necessary.
Several other chemicals were eliminated from the PAA list for various reasons. Although ^7FI6
(perfluoroheptane) and C7F14 (perfluorocycloheptane) have estimated boiling points below 20 °C, it is believed that
these estimates are high since the smaller homolog C6F14 has a known boiling point of 57 °C. These
perfluoroheptanes were thus eliminated from the list of PAAs. On the other hand, since the known boiling point
for HFC 236cb (CH2FCF2CF3) was only slightly above the 0 °C cutofT(1 °C), it was lefl on the PAA list; however,
very little information is available on this material, so it was classified as a Group 3 candidate.
SELECTION CRITERIA
Available information on the PAA candidates was collected, compiled, assessed, and, if not already
present, entered into the NMERI HALOCARBON DATABASE® The majority of this information is derived
from the work performed under Air Force sponsorship on replacement streaming agents; however, little assessment
of available information on low boiling compounds has been performed since these materials do not hold great
promise as Halon 1211 streaming replacement agents, the objective of the present Air Force initiative at
CGET/NMERI. Sources for the information included the open literature, other databases, and industry contacts.
The following criteria must be considered when screening and ranking candidate agents: physical properties,
chemical stability, toxicity, availability and cost, materials compatibility, cleanliness, fire suppression capabilities,
and environmental considerations. Regulatory concerns are included in Appendix B.
6
-------
Physical Properties
The effectiveness of an explosion or fire suppression agent in real-world, large-scale fires depends on
agent deliveTability, heat removal capability, and radical reaction termination capability. The physical properties
to be considered when determining the potential of a chemical for total-flood applications include, but are not
limited to, boiling point, melting (freezing) point, vapor specific heat, heat of vaporization, vapor pressure (at room
temperature), heat of reaction to form products of C02 and halogen acids using H20 as an oxygen and hydrogen
source, viscosity, and vapor and liquid density. Some properties relate primarily to dcliverability (e.g., boiling
point, vapor density, viscosity, and vapor pressure) and some to extinguishing ability (e.g., vapor specific heat and
heat of vaporization). Physical properties are not available for many of the listed PAA candidates. For compounds
that appear particularly promising but for which important physical properties are needed, some properties may
need to be determined in the laboratory. Table 3 presents selected known physical properties for the PAAs.
A replacement total-flood action agent should have a boiling point such that it can be delivered as a gas,
thus the arbitrary cut-off (0 °C) used here. The vapor pressure at room temperature should be adequate for rapid
dispersal, but not so high as to require extremely heavy-duty high pressure equipment to contain it. Stored agents
in cylinders are in the liquid state if the pressure is greater than the vapor pressure of the agent. Normally,
halocarbons are stored as liquids, since agent storage pressures arc on the order of 400 psi and vapor pressures are
well below this. For effective heat removal, an agent should have a high vapor specific heat and high heat of
vaporization. Ideally, the vapor specific heat should be equal to or higher than that of the existing agents
(0.11 cal/g-°C each for Halons 1301 and 1211), as should the heat of vaporization (28.4 cal/g for Halon 1301). All
the agents listed in Table 2 with known vapor specific heat and heats of vaporization are above these minimum
values with the exception of HFC-125, which has a heat of vaporization equal to 27.1 cal/g. However, no agents
w ere strictly disqualified if they did not fall within these ranges.
The freezing (melting) point of the agent should preferably be below -60 °C. In normal use the agent
should not experience temperatures below 0 °C, however, cylinders of agent being transported outdoors in Alaska
in wintertime could conceivably be exposed to temperatures as low as -60 °C. Normally, organic liquids contract
upon solidification. Thus, even if the agent solidifies briefly, it is not expected to exert high pressures against the
walls or valves, and upon wanning again to ambient temperature, the system is expected to behave normally. The
known melting points of agents in Table 2 are all below -60 °C.
7
-------
TABLE 3. SELECTED PHYSICAL PROPERTIES OF PHYSICAL ACTION AGENTS*
Halocarbon
no.
Formula
Molecular
weight
(g/mole)
Boiling
point
PC)
Melting
point
<°C>
Density
(g/ml)
Vapor
specific
heat
(cal/g-°C)
Heat of
vaporization
(cal/g)
Extinguishment
concentration in
cup burner
(%)
Halon 1301
(as reference)
14
22
23
31
32
116
124
124a
125
134
134a
142a
142b
143a
152a
C216
218
226ba
227ca
227ea
C234
2356a
235cc
235ca
235ba
235eb
235ea
235bb
236cb
236fa
244db
244da
244fb
244bb
244ca
244cb
244ba
244ea
244eb
244fa
244ec
245c b
245ea
245eb
245ca
2S4ea
254c b
254eb
254fa
254ca
3-1-10
C318
CF3Br
CFi
chcif2
ghf3
ch2cif
ch2f2
CFtCFo
chcifcf3
chf2ccif2
chf2cf3
chf2chf2
ch2fcf3
chcifch2f
ccif2ch3
CH3CF3
chf2ch3
cf2cf2cf2
cf3cf2cf3
cf3ccifchf2
cf3cf2cf2h
cf3chfcf3
cf2cf2ch2
cf3chcichf2
ch2fcf2ccif2
chf2cf2chcif
CHF2CCllrCHF2
chf2chfccif2
cf3chfchcif
CF3CCIFCH2F
CH2FCF2CRj
cf3ch2cf3
CFgCHCICH^
chf2chcichf2
ccif2ch2chf2
cf,ccifch3
,cf2ch2ci
ch2Pcf2chcif
CHF2CCfroH2F
chf2chfchcif
cf3chfch2ci
cf3ch2chcif
ccif2chfch2f
cf3ct2ch3
C H F 2CH F ch f 2
cf3chfch2f
chf2cf2ch2f
chf2chfci-(^f
chf2cf2ch3
cf3chfch3
chf2ch2chf2
ch,fcf2ch2f
cV°
4 8
CHF
148.9
88
86.47
70.01
68.48
52.02
138.01
136.48
136.48
120.02
102.03
102.03
100.5
100.5
84.04
66.05
150.02
188.02
186.48
170.03
170.03
114.04
168.49
168.49
168.49
168.49
168.49
168.49
168.49
152.04
152.04
150.5
150.5
150.5
150.5
150.5
150.5
150.5
150.5
150.5
150.5
150.5
134.05
134.05
134 05
134.05
116 06
116.06
116.06
116.06
116.06
238.03
200.3
-58
-168
1.57
0.111
28.4
-129
-184
3.03
0.169
32.5
-41
•160
1.17
0158
48.4
-82
-155
1.52
0174
57.3
-9
-133
1.27
0.164
-
-52
-136
1.20
0197
69.4
-79
-100
1.59
0.182
28.1
-12
-199
1.38
0.198
40.1
-10
-117
1.28
0178
-
-49
-103
1.23
0188
27.1
-20
-89
-
-
50. ot
-27
15t
-101
1.2
0.204
50.0
-10
-204
1.11
0.197
52.8
-48
-111
—
0.222
-24
-117
0.95
0.245
53.0t
-32
_
_
_
33,0t
-17
-183
1.45
0.188
75.4
-148
1.39
-t5
-t|t
iot
-127
1.42
—
32.0
lot
lot
10t
10t
lot
lot
—
! ! ! ! ! !
—
—
1
-105
1.337
—
39.7
-1
19t
19t
19t
-94
1.37
—
—
—
—
—
19t
1Qt
19t
19t
19I
19t
| j I i I !
—
—
—
19t
19t
—
—
—
—
-18
-27t
-27t
25
-iet
-0.8
-17t
-81.1
1.20
—
-73.4
1.336
—
—
-121.1
1.192
—
55.0
-17t
-17t
—
—
—
—
-5
-85
1.52
—
—
-6
-40
1.48
0.273
28.0t
14
12
lit
9
8
8t
9
11
10.5
1lt
II
20t
27
III
6
7t
10t
10t
15t
8*
8t
8t
8t
8t
8t
6t
11*
11T
8^
8t
8t
8t
81"
8t
8^
8t
at
at
at
13t
13t
13t
1st
15t
15t
15t
15t
5
7
* Data taken from the NMERI Halocarbon Database^ (3).
t Estimated.
8
-------
Chemicals with low molecular weights and high densities are attractive alternative agents. Most agents
that do not contain bromine have significantly lower molecular weights than Halon 1301. A lower molecular
weight means that a lower mass can provide an equal gas-volume concentration of agent, or, equivalently, that the
same mass of agent will provide a higher gas-volume concentration, as the following example illustrates. It takes
20.6 g of Halon 1301 (molecular weight 148,9) to provide a 6-percent concentration in a 66.9-liter test container at
the barometric pressure at the NMERI test site (Albuquerque, NM, altitude 5680 ft), and the temperature (25 °C) at
which testing occurred. For the candidate alternative agent HFC-23 (CHF3, molecular weight 70) only 9.7 g are
required to achieve a 6-percent concentration. At the same temperature and pressure, a mass of HFC-23 equal to
that of Halon 1301 (20.6 g) would provide a concentration of 12.8 percent. The volume of 20.6 g of liquid
Halon 1301 (density 1.50 g/mL at 25 °C) is 20.6 g x 1.00 mL/1.50 g = 13.7 mL. The volume of the same mass of
HFC-23 (density 1.52 g/rnL at 25 °C) is 20.6 g x 1.00 mL/1,52 g = 13.6 mL,
Thus, a concentration of 12.8 percent HFC-23 could be obtained with the same mass (and slightly lower
volume of stored agent) as a 6-percent concentration of Halon 1301. If, for example, HFC-23 proved effective at
less than 12.8 percent, it would have advantages in both mass and volume of agent over Halon 1301. It should,
however, be noted that a 6-percent Halon 1301 concentration implies a safety factor of approximately 1.5 to 2.0
above typical measured cup-burner extinguishment concentrations. Alternative agenl tradeoffs may require a risk
assessment to include a design safety factor adjustment. However, this example illustrates that a less effective
agent may be used and it may not require an increase in volume for storage.
Chemical Stability
Since agents are often stored for long periods before use, sometimes under extremes of temperature,
agents must be chemically stable during long-term storage. Chemical stability implies the absence of easy
decomposition pathways. Common pathways of chemical decomposition include thermal homolytic cleavage of
weak carbon-to-halogen bonds, loss of a molecular dihalide (e.g., Br2). hydrolysis, and reaction with metals.
Highly fluorinated chemicals are less likely to undergo the oxidative reactions that often destroy molecules
containing carbon-to-hydrogen bonds. The high electronegativity of fluorine (most electronegative element) causes
a partial positive charge to develop on a carbon atom attached to it. This, in turn, strengthens the bond of a
chlorine, bromine, or iodine atom attached to that carbon atom. In addition, carbon-fluorine bonds are very strong
and unreactive when compared to carbon-to-hydrogen bonds. The presence of fluorine atoms confers greater
chemical stability, which accounts in large part for the stability of existing halons.
During initial screening, agents containing particularly weak carbon-to-halogen bonds arc ranked lower
than comparable agents with stronger bonds. For example, any chemicals containing carbon-to-iodine bonds or
containing a bromine atom on either a secondary or tertiary carbon atom or a carbon not attached to fluorine are
9
-------
less stable than comparable agents not containing those arrangements of atoms. The compounds under
consideration here do not contain any particularly unstable functional groups, and chemical stability is not
expected to be a problem for any of them. Nonetheless, most organic chemicals will decompose to some degree on
prolonged storage, so testing is needed to determine stability under storage conditions.
Toxicity
It is desirable that an alternative agent be as nontoxic as possible, preferably comparable to or lower than
existing halons in toxicity. Exposure of personnel to agents can occur during manufacturing, handling, system
maintenance storage, and real and false dumps. Toxicity testing is the most time-consuming part of studies of
potential fircfighting agents. Under the accelerated testing schedule of the Programme for Alternative
Fluorocaibon Toxicity Testing (PAFTT), thorough testing of a new compound can require up to six years (5).
Consequently, compounds considered for deployment in the near term must have already had significant toxicity
testing completed; however, only a select number of haiocarbons arc being tested under PAFTT and these
chemicals are primarily under investigation as CFC alternatives (Table 4).
TABLE 4. HALOCARBONS BEING INVESTIGATED UNDER PAFTT
PAFTT Compound Companies Expected completion date
I HCFC-123 Akzo, Allied-Signal, Asahi Glass, 1992
HFC-134a Atochem Daikin, Du Pont, Hoechst, ICI, 1993
ICS, Kalie Chemie/Solvay, Montefluos,
Racon, Showa-Denko, Visan
II HCFC-141b Akzo, Allied-Signal, Asahi Glass, 1993
Atochem, Daikin, Du Pont, Kalie
Chemie/Solvay, Pennwalt,
Showa-Denko
III HCFC-124 Allied-Signal, Aotchem, Daikin, ICI 1994 or 1995
HCFC-125 Chemicals, ICS Chemicals, Montefluos
IV HCFC-225ca Allied-Signal, Asahi Glass, Central 1995 or 1996
HCFC-225cb Glass, Daikin, Du Pont, ICI Chemicals
Considerations of the short- and long-term health hazards of exposure, the relationships between chemical
structure and toxic effects, and biodegradation and production of reactive metabolites arc all of key importance
when deciding which compounds hold potential for future use in explosion and fire suppression. Human and
animal research indicates several principal adverse effects of haiocarbons. First, they can stimulate or suppress the
central nervous system (CNS) to produce symptoms ranging from lethargy and unconsciousness to convulsions and
tremors (6), Second, haiocarbons can cause cardiac arrhythmias and can sensitize the heart to epinephrine
(adrenaline) (7). Third, inhalation of haiocarbons can produce bronchioconstriction, reduce pulmonary
compliance, depress respiratory volume, reduce mean arterial blood pressure, and produce tachycardia (rapid
heartbeat) (8), Fourth, these agents can cause organ damage by degradation products of metabolism (9). Lastly,
10
-------
halocarbons can produce cancerous or mutagenic effects (8). CNS effects, cardiac sensitization, and pulmonary
disorders appear to be reversible upon termination of exposure to these chemicals. Organ toxicity, cancer and
mutagenicity, on the other hand, are latent effects, and sequelae (delayed effects due to the compound or its
metabolites) are usual.
The immediate effects of halocarbon exposure on the nervous system, cardiovascular system, and
respiratory system appear to be caused by the compound itself. However, it is thought that the latent effects that
take place in specific organs, such as the liver, kidneys, and lungs, are possibly caused by the degradative products
formed when the halocarbons enter into metabolic processes. Both the immediate effects and the latent damage
must be considered when evaluating potential candidates for flrefighting agents. Although generalization to the
entire class of halocarbons would be convenient, toxicity information on each candidate must be individually
acquired in order to assess fully its potential health hazards.
The relationship between chemical structure and toxicity has been explored in simple halogenated
alkanes. Evidence indicates that the greater the number of fluorine atoms and the fewer the number of chlorine,
bromine, and iodine atoms present on the molecule, the lower the toxicity of the compound. Even with the
replacement of only one chlorine by fluorine (e.g., HCFC-22 versus HCFC-21), a notable reduction in toxicity, as
indicated by exposure limits, is observed. The same trend is seen in perhalogenalcd methanes, where, for example,
CFC-14 is much less toxic than CC-10 (CC14). Similarly, toxicity is decreased when bromine or iodine atoms are
replaced by fluorine. Also, when hydrogen is replaced with fluorine, a reduction in toxicity occurs. The same
trends hold for halogenated ethanes, propanes, and butanes, in which the reduction of toxicity is a function of
increasing fluorination at the expense of hydrogen, chlorine, and bromine or iodine. In haloalkancs of two or more
carbons, when four fluorine atoms are present on the molecule, the number of hydrogen atoms appears to have less
of an effect on the toxicity. Thus, targeting FCs and highly fluorinaled HFCs holds the highest potential for
nontoxic Halon 1301 alternatives.
Since low toxicity is extremely important for total-flood applications in normally inhabited areas, it is
essential that all known toxicity information be assessed carefully. This evaluation is needed to avoid expenditures
of time or money to evaluate compounds that could not ultimately be used. In order to assess accurately the toxic
potentials of Ihe PAA chemicals, all the publicly available toxicity information available on these chemicals was
collected and evaluated. The information was collected by performing on-line computer searches of toxicological
databases such as Toxlit, Toxline, and Chemical Abstract Services, manual searches, and in certain circumstances
by collecting unpublished information from industry contacts. For many chemicals, little, if any, toxicological
information is readily available. For some chemicals, some information is available, but it is in obscure journals
and foreign languages. For others, such as HCFC-124. toxicological testing is currently underway through PAFTT
11
-------
and results will be made available as they are analyzed. Consequently, the toxicity evaluation will be an ongoing
analysis throughout most of this project as more information becomes available.
As an additional measure, those chemicals with 110 known information were assessed through quantitative
structure-activity relationships (QSARs) to achieve initial estimates of anesthetic potential and lethal index.
Estimated anesthetic dose to anesthetize 50 percent of a mouse population in 30 minutes (AD;o) and the lethal
concentration to kill 50 percent of a mouse population in 30 minutes (L€;o) were calculated using an algorithm
derived from the well-known relationship between these parameters and boiling points (10). These values only
provide initial screening information and will need to be validated with experimental testing. Table 5 provides
estimated or available information on acute lethal, anesthetic, and mutagenic/oncogenic effects of PAAs.
Toxicity Summaries-
This section provides summaries of known toxicity information on PAAs. The chemicals in other groups
generally do not have much, if any, more information than is presented in Table 5. HFCs 32, 143a, and 152a and
HCFC 142b are included in this summary although they could only be used as minor components in blends.
Except as noted, the toxicities of combustion byproducts are not discussed in this report. Hydrogen
fluoride (HF), carbon monoxide (CO), and carbonyl fluoride (COF;) are toxic combustion byproducts common to
all of the materials evaluated in this report. The formation of significant amounts of free fluorine (F2) is unlikely.
In addition, hydrogen bromide (HBr), carbonyl bromide (COBr2), and some free bromine (Br>) are likely
byproducts for bromine-containing chemicals (e.g., HBFCs); hydrogen chloride (HCl). carbonyl chloride
(phosgene, COCl2), and limited chlorine (CI;) are possible for chlorine containing materials (e.g., HCFCs); and
hydrogen iodide (HI) and free iodine (I2) are likely for iodine-containing chemicals (e.g., FICs). Due to its low
stability, carbonyl iodide is not likely to be formed. When more than one type of halogen is contained by a
chemical, mixed carbonyl compounds such as COC1F may also be formed. The toxicities of many of these
byproducts are well documented (see, e.g., Reference 11). The amounts of toxic byproducts actually formed are
very scenario dependent. Contact with hot metal surfaces appears to cause relatively little decomposition. On the
other hand, prolonged contact with open flames may cause formation of large amounts of toxic materials. Rapid
extinguishment of fires is unlikely to cause problems with byproducts. Ineffective extinguishment may produce
large amounts of toxic gases.
FC-14: Of the polyfluorinatcd methanes, FC-14 (periluoromcthane) is considered to be the least toxic. In
1960, the American Conference of Governmental Industrial Hygienists (ACGIH) set the maximum allowable
concentration at 1000 ppm (12), This rating was based on findings from Underwriters' Laboratories that exposure
at 20 percent for 2 hours did not produce death in guinea pigs. Although these data are somewhat dated, FC-14 is
still today considered biologically inert.
12
-------
TABLE 5. TOXICITY OF PHYSICAL ACTION AGENTS
Halocarbon no.
Formula
ADgo*
(Vol. %)
Time
Species
Note/
Ref.
LC501
(Voi%)
Time
Species
Note/
Ref.
Mutagenic
Evidence
Study
Note/
Ref.
Halon 1301
(as reference)
CF3Br
50
2hr
Rat
est
40-80
4hr
Rat
est
Nonmut
Vitro/Rat
13
14
U-
o
>80
30min
Mice
est
>80
30mln
Mice
est
N/A
N/A
N/A
22
chcif2
20.49
30min
Mice
14
27-30
N/A
Rat/Guinea
15
Mutagenic
In vitro
16
23
chf3
>18
4hr
Rat
17
66.3
4hr
Rat
18
Mutagenic
Fr.Flies
16
31
ch2cif
2
4hr
Rat
16
4.5
4hr
Rat
16
Mutagenic
Vitro/Rat
16
32
^2^2
53
30min
Mice
est
>76
*ir
Rat
16
Nonmut
In vitro
15
116
cf3cf3
>80
30rnln
Mice
est
>80
4hr
Rat
m
Nonmut
In vitro
16
124
chcifcf3
15.49
30m in
Mice
13
23-36
4tir
Rat
14
Nonmut
In vitro
15
124a
chf2ccif2
15
30m in
Mice
est
>20
2hr
Guinea
201
N/A
N/A
125
chf2cf3
>57
30min
Mice
est
70
4hr
Rat
14
Nonmut
In vitro
15
134
chf2chf2
20
30m in
Mice
est
39
SOmin
Mice
est
Nonmut
In vitro
15
134a
CH2FCF3
30
30min
Mice
est
50
4hr
Rat
21
Nonmut
Vitro/Rat
15
142a
chcifch2f
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
142b
ccif2ch3
23.1
30min
Mice
13
>30
30min
Rat
14
Mutagenic
In vitro
15
143a
ch3cf3
50-60
10min
Mice
22
84
30min
Mice
est
Mutagenic
In vitro
15
152a
chf2ch3
24
30mir
Mice
est
385
4hr
Rat
12
Nonmut
Vitro/Rat
12
C216
cf2cf2cf2
31
30min
Mice
est
54
30min
Mice
est
N/A
N/A
218
cf3cf2cf3
>36
30min
Mice
est
>80
1 hr
Rat
16t
Mutagenic
In vitro
16
226ba
cf3ccifchf2
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
N/A
227ca
cf3cf2cf2h
>12
12min
Mice
23
40
4min
Mice
22
N/A
N/A
N/A
227ea
cf3chfcf3
17
30min
Mice
est
34
30min
Mice
est
N/A
N/A
N/A
234
cf2cf2ch2
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
N/A
235da
cf3chcichf2
1
5mri
Mice
24
6.57
5min
Mice
23
N/A
N/A
N/A
235cc
ch2fcf2ccif2
10
10min
Mice
19
15
lOmin
Mice
19
N/A
N/A
N/A
235ca
chf2cf2chcif
2.5
10min
Mice
19
3
10min
Mice
19
N/A
N/A
N/A
236cb
ch2fcf2cf3
10
30min
Mice
est
22
30min
Mice
est
N/A
N/A
N/A
236fa
CF3CH2CF3
11
10min
Mice
21
44
10min
Mice
21
N/A
N/A
N/A
244db
CF,CHCICH,F
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
N/A
(continued)
-------
TABLE 5. (concluded)
Halocarbon no. Formula
a050*
Time
Species
Note/
LC50t
Time
Species
Note/
Mutagenic
Study
Note/
(Vol. %)
Ref.
(Vol %)
Ref.
Evidence
Ref.
244da CHF2CHCICHF2
0.64
5min
Mice
19
8.1
5min
Mice
19
N/A
N/A
244ft) CCIF2CH2CHF2
10
10min
Mice
19
20
lOmin
Mice
19
N/A
N/A
244tt> CF3CCIFCH3
1.05
5min
Mice
19
3.79
5min
Mice
19
N/A
N/A
244ea CHF2CF2H2CI
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
244cb CH2FCF2CHCIF
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
245cb CF3CF2CH3
19
30min
Mice
es?
37
30min
Mice
est
N/A
N/A
245ea CHF2CHFCHF2
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
245eb CF3CHFOH2F
Nifi
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
245ca CHF2CF2CH2F
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
254ea CHF2CHFCH2F
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
254cb CHF2CF2CH3
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
254eb CF3CHFCH3
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
254ca CH2FCF2CH2F
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
254fa CHF2CH2CHF2
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
3-1-10 C4F10
N/A
N/A
N/A
§
N/A
N/A
N/A
§
N/A
N/A
C318 C4F8
>80
6hr
Rat
19
>80
6hr
Rat
19
N/A
N/A
'Anesthetic dose to anesthetize 50% of an animal population.
tLethal concentration to kill 50% of an animal population,
t Approximate lethal concentration.
§ Unable to estimate.
N/A=Not available.
-------
HCFC-22: The toxicity of HCFC-22 (dichlorofluoroethane) has been studied extensively. In 1984,
Litchfield and Longstaff (18) published a comprehensive review of literature reporting HCFC-22 toxicity, which
showed that HCFC-22 has a low acute inhalation toxicity. This was confirmed in several animal species, where
the compound was either not lethal or was lethal at concentrations ranging from 20 percent for 5 minutes in
monkeys to 70 percent for 90 minutes in dogs. The signs of acute toxicity show HCFC-22 to be a CNS depressant.
When death occurs during exposure, it is due to respiratory depression. Recovery from non-lethal doses occurs
rapidly; animals appear normal within a few minutes with no sequelae. This recovery parallels the rapid
elimination of HCFC-22, from the bloodstream, with a half-life of only a few minutes. Acute inhalation of
40 percent HCFC-22 in anesthetized mice sensitized the heart to epinephrine-induced arrhythmias. Acute
exposure to anesthetized monkeys produced no arrhythmias, but myocardial depression with inhaled
concentrations of 2.5 to 10 percent was noted. Inhalation of HCFC-22 in anesthetized monkeys caused a reduction
in respiratory minute volume and blood pressure, with increased pulmonary resistance and heart rale. Cardiac
arrhythmias were not seen in the dog, monkey, or mouse in the absence of injected adrenaline at concentrations of
5, 20, and 40 percent, respectively. With injected adrenaline and inhalation of HCFC-22, cardiac arrhythmias
were induced in the dog and mouse, but not the monkey. The minimum concentration at which cardiac
sensitization occurred in dogs given injected adrenaline was 5 percent HCFC-22 (LOAEL).
F.vidence indicates that HCFC-22 metabolism is minimal. This resistance to biological breakdown
suggests that any potential biological activity is unlikely to be due to reactive metabolites. On the basis of
mutagenic studies, HCFC-22 appears to be a bactcria-specific mutagen and is unlikely to pose a genetic hazard to
humans. Except for one report out of several, HCFC-22 is not reported to elicit adverse reproductive effects in
rodents. A recent chronic exposure study established a clear no-effect level at 10,000 ppm. At 50,000 ppm,
histological examination revealed no effects on the respiratory, cardiovascular, or reproductive systems in chronic
studies on rats. With the exception of one study, none found carcinogenic effects of HCFC-22 in long-term studies
involving rodents. The one exception showed salivary gland fibrosarcomas in male rats exposed to 50,000 ppm.
According to these data and limited human information, a threshold limit value (TLV) of 1000 ppm was
supported.
HFC-23: HFC-23 has very low acute inhalation toxicity. No deaths occurred when rats were exposed to
very high concentrations of HFC-23; the 4-hour Approximate Lethal Concentration (ALC) in rats was greater than
663,000 ppm in air. Slight anesthetic effects, e.g., reduced response to sound and weakness (lethargy), were
observed at 18,600 ppm, and severe nervous system effects, non-responsiveness to sound, sluggishness, and labored
breathing, were evident at 630,(KM) ppm. No cardiac sensitization was observed in dogs exposed to 800,0CM) ppm
HFC-23 with added oxygen. In more recent studies, HFC-23 did not produce a cardiac response in dogs up to
300,000 ppm, without added oxygen, or up to 500,000 ppm with added oxygen. HFC-23 is not expected to cause
15
-------
skin or eye irritation, and the effects from massive inhalation exposures indicate that HFC-23 does not cause
irritation of the respiratory tract.
A 90-day inhalation study with rats was conducted at 10,000 ppm HFC-23. No effects were observed
during exposures, and no changes in histopathology were evident at the end of the study. Similarly, no adverse
effects were noted in a 90-day inhalation study in dogs exposed to 5000 ppm HFC-23.
HFC-23 was not mutagenic in S. typhimurium (Ames) study, but was reported to be mutagenic in D.
melangastor. However, this latter study has been criticized by the EPA, and the results were considered to be
inconclusive because of the methodology used in that study.
No carcinogenicity or developmental toxicity studies with HFC-23 have been conducted. However,
HFC-23 is an inert material as demonstrated by the lack of biological effects in two species of animals exposed by
inhalation up to 10,000 ppm. Also, HFC-23 would not be expected to be metabolized, and thereby eliminated from
the body unchanged, suggesting that it is biologically inert. Therefore, HFC-23 would not be expected to provoke
any long-term health effects from repeated exposures.
Overall, the toxicity data for HFC-23 clearly demonstrates that this material is inert, i.e., no significant
adverse effects are observed in experimental animals unless exposures concentrations reach approximately
663,000 ppm. No long-term human health effects would be expected from repeated exposures to HFC-23 because
the material is considered to be inert. The Du Pont Acceptable Exposure Limit (AEL) for HFC-23 is 1000 ppm, 8-
and 12-hour time weighted average, the highest exposure limit assigned to chemicals.
HFC-32: The toxicity of HFC-32 was reviewed by Du Pont's Haskell Laboratory (25). Acute inhalation
studies in rats revealed that clinical signs of toxicity during exposure to HFC-32 included lethargy, loss of mobility
in hind legs, spasms, and gnawing on the bottom of the cage. No abnormal signs were noted after the exposure
and mobility returned within one-half hour afler exposure ceased. Gross pathological examination did not reveal
any changes in the animal's organs attributed to the test material. The potential of HFC-32 to sensitize the heart to
epinephrine challenge was tested in canines. One out of 12 dogs tested experienced sensitization at 250,000 ppm
but not 200,000 ppm. Longer term inhalation studies revealed no clinical, hematological, blood chemistry, urine
analytical, or histopathological evidence of toxicity due to repeated HFC-32 exposure. HFC-32 was shown not to
be mutagenic in several in vitro assays. No carcinogenic evidence is available. Metabolic studies revealed that
HFC-32 is metabolized similar to other dihalomethanes.
HFC-32 was added to PAFTT and a summary of these finding is provided below (26). HFC-32 has a very
low order of acute toxicity, and the 4-hour LCjq is in excess of 520,000 ppm, A study to assess whether HFC-32
had the potential to sensitize the heart to adrenaline has been carried out, and no abnormal cardiac responses were
16
-------
found over the range from 150,000 ppm to 350,000 ppm. HFC-32 has been demonstrated to be inactive in the
Ames cell mutation assay, and in in vitro clastogenicity studies, both with and without metabolic activation.
Studies still in progress are a Chinese Hamster Lung in vitro assay and an in vivo rat liver unscheduled DNA
synthesis (UDS) study. A 28-day repeated exposure inhalation study using the rat has shown that HFC-32 had no
adverse effects at the highest concentration tested (50,000 ppm). A developmental toxicity screening test in the rat
using exposures up to 50,000 ppm, based on the Chemoff-Kavlock method, showed no indications of potential
developmental toxicity . The need for further toxicity testing with long-term exposures will be assessed in the light
of results from the current programs when they arc all available. In summary, the PAFTT V on HFC-32 is now
fully under way. All results available to date show that there is nothing to preclude the use of HFC-32 in general
industrial uses, presided that the recommended normal hygiene practices are observed.
FC-116: This chemical is relatively nontoxic in moderate concentrations (27). Laboratory animals
exposed to the chemical during acute inhalation studies survived the treatment and observation period. However,
while breathing the compound, rats did experience deep, rapid, and irregular breathing with obvious discomfort at
the lower concentration (200,000 ppm) and signs of cutaneous dilation at the higher concentration (800,000 ppm).
No pathological abnormalities were noted in rals exposed to the lower concentration, but pulmonary lesions were
more prevalent in rats exposed to the high concentration. FC-116 did not produce cardiac sensitization in dogs
exposed to the chemical by itself, but did increase the arrhythmogenic activity of an intravenous epinephrine
challenge in guinea pigs, cats, and dogs. Continuous exposure of rats to 207,000 ppm for 37 weeks produced no
abnormalities in growth rates, serum chemistry, or hematology. No evidence of increased fluoride metabolism was
revealed, although other studies have indicated an increase in fluoride metabolism. Pathological examination
failed to show any adverse change. FC-116 was shown not to be mutagenic in E. coti.
HCFC-124: One of a series of fluorocarbon alternatives being tested by PAFTT, HCFC-124 has very low
acute toxicity by inhalation. The lowest concentration that causes mortality in experimental animals, i.e., the
approximate lethal concentration (ALC) for a 4-hour exposure, is between 230,000 and 300,000 ppm in rats.
Similar exposure levels cause toxicity in other species, such as the guinea pig. During inhalation exposure to very
high concentrations, anesthetic-like effects, e.g., weakness and in coordination, are observed. The 10-minute
exposure concentration that causes these effects (ECJ0 for nervous system effects in experimental animals) is about
140,000 ppm. Similar anesthetic-like effects are observed with many other fluorocarbons in acute inhalation
studies.
As with many other halocarbons and hydrocarbons, inhalation of HCFC-124, followed by intravenous
injection of epinephrine that stimulates human stress reactions, results in a cardiac sensitization response in
experimental screening studies with dogs. This cardiac sensitization response is observed at approximately
17
-------
25,000 ppm HCFC-124, a level well above expected exposures. By comparison, a cardiac sensitization response is
observed with CFC-11 at approximately 5000 ppin.
Longer-term studies of up to 90 days in duration have also been conducted with HCFC-124. Only
changes in clinical chemistry parameters (e.g., triglycerides) and anesthetic-like effects were noted. These were
observed only in the 90-day study. No other effects were evident in any of these studies at concentrations of up to
100,000 ppm. In a 90-day study with mice, inhalation exposures caused an increase in beta-oxidation (indicative
of peroxisome proliferation) and a decrease in triglycerides. No other toxic effects were noted in this 90-day study.
A two-year inhalation study with HCFC-124 started in November 1992, with exposure concentrations of
0, 2000, 10,000, and 50,000 ppm. Results from this study are not expected until 1995,
Several genetic toxicity studies liave also been completed with HCFC-124. Based on the evidence from all
in vitro and in vivo studies, HCFC-124 is not genotoxic. Studies conducted with HCFC-124 include Ames, mouse
micronucleus, and in vitro chromosomal aberration with human lymphocytes.
The results from developmental toxicity studies with HCFC-24 show that this material does not have
embryo toxic or teratogenic effects in rats or rabbits. At very high concentrations, e.g., 50,000 ppm, anesthetic-like
effects and reduced body weights are observed in pregnant animals. However, no fetal effects have been observed
at these high, maternally toxic concentrations.
HCFC-124 is oxidatively metabolized by the body following inhalation exposure, as suggested by a slight
increase in urinary fluoride levels. Also, trifluoroacctic acid (TFA) has been detected following HCFC-124
administration.
In summary, HCFC-124 has low toxicity. Results from testing completed so far indicate that HCFC-124
(1) has very low acute and subchronic inhalation toxicity
(2) is not a developmental toxicant
(3) is not genotoxic
An exposure limit of 1000 ppm, 8-hour time-weighted average, has been recommended by the American
Industrial Hygiene Association. Workplace Environmental Exposure Limit (WEEL) Conunittee.
HFC-125: One of a series of fluorocartxm alternatives being tested by the PAFTT, HFC-125 has very low
toxicity by inhalation. The lowest concentration that causes mortality in experimental animals, the approximate
lethal concentration, or ALC, for a 4-hour exposure is greater than 80 percent with added oxygen. Even at these
high inhalation concentrations, no clinical signs of toxicity are evident.
18
-------
As with many other halocarbons and hydrocarbons, inhalation of HFC-125 followed by intravenous
injection of epinephrine, to simulate human stress reactions, results in a cardiac sensitization response in
experimental screening studies with dogs. This cardiac sensitization response is observed at approximately
100,000 ppm of HFC-125, a level well above expected exposures. By comparison, a cardiac sensitization response
is observed with CFC-11 at approximately 5000 ppm.
In repeated inhalation exposure studies, the low toxicity of HFC-125 continues to be evident. No adverse
effects were observed in rats exposed by inhalation at concentrations of up to 50,000 ppm for up to 90 days.
Inhalation developmental toxicity studies with rats and rabbits have been completed. The results indicate
that HFC-125 is not teratogenic and does not cause fetal effects at inhalation concentrations up to 50,000 ppm.
In genetic toxicity testing, HFC-125 was not mutagenic in an Antes assay, Chinese Hamster Ovary assay,
or chromosomal aberration study with human lymphocytes. These studies were in vitro assays. Also, HFC-125
was not active in an in vitro mouse micronucleus study.
Metabolism studies with HFC-125 have not detected any abnormalities.
In summary, HFC-125 has very low toxicity. Results from testing completed so far indicate that HFC-125
(1) has very low acute and subchronic inhalation toxicity
(2) is not a developmental toxicant
(3) is not mutagenic
Several PAFT companies have set occupational exposure limits for HFC-125, typically at 1000 ppm
(8-hour time-weighted average).
HFC-134a: HFC-134a is one of a series of fluorocarbon alternatives being studied as part of PAFTT.
HFC-134a is being considered as an alternative for refrigeration and air conditioning, medical dose delivety
systems, and as a foam blowing agent.
HFC-134a has very low acute inhalation toxicity . The lowest concentration that causes mortality in rats,
the approximate lethal concentration (ALC) for a 4-hour exposure, is greater than 500,000 ppm. Anesthetic-like
effects, e.g., lethargy and in coordination, are observed in rats at very high inhalation concentrations (greater than
200,000 ppm).
As with many other halocarbons and hydrocarbons, inhalation of HFC-134a followed by intravenous
injection of epinephrine, to simulate human stress reactions, results in a cardiac sensitization response in
experimental screening studies with dogs. This cardiac sensitization response is observed at approximately
19
-------
75,000 ppm of HFC-134a, a level well above expected exposures. By comparison, a cardiac sensitization response
is observed with CFC-12 at approximately 50,000 ppm.
Longer-term studies have also been conducted with HFC-134a No significant toxicological effects were
observed in rats following inhalation exposure for up to one year at concentrations up to 50,000 ppm.
At the end of the two-year inhalation study, no effects were observed in body weights, in-life
measurements, clinical observations or clinical chemistry, or hematology . Except for the testes of male rats, no
grossly visible or microscopic changes were observed in any of the HFC-134a exposed rats. At 50,000 ppm, an
increased incidence of hyperplasia (cell growth) and benign tumors of Ley dig cells was observed on microscopic
examination of the testes. No malignant tumors attributable to exposure to HFC-134a were observed. An
independent review of the pathology findings supported these conclusions. None of the benign tumors was life-
threatening. and all occurred near the end of the study. No effects were observed at lower concentrations in this
2-year study; the NOAEL was 10,000 ppm.
Several genetic toxicity studies with HFC-134a have been completed. These included a bacterial reverse
mutation (Ames) test, an in vitro chromosomal aberration study with human lymphocytes, and a cytogenetics assay
with Chinese Hamster Lung Cell (CHL). In vivo studies included cytogenetics, mouse micronucleus, and a
dominant lethal study in the mouse. Evidence from all in vitro and in vivo studies clearly indicates that HFC-134a
is not genotoxic. Furthermore, these data and data obtained from the two-year inhalation study suggest that the
increased incidence of benign tumors observed in the two-year inhalation study is not due to an effect on genetic
material.
Results from inhalation development toxicity studies indicate that HFC-134a docs not cause teratogenic
effects in rats or rabbits. At inhalation concentrations of 300.000 ppm, slight maternal toxicity and
embryotoxicity, evidenced by a decrease in fetal body weights, are observed in rats. Lower fetal body weights of
rats and rabbits have also been observed at 50,000 ppm with slight maternal toxicity . Lower maternal body
weights were also observed in rats at this concentration. In an additional study, no fetal effects are observed in
rabbits at inhalation concentrations of up to 40,000 ppm.
Although not metabolized to any significant extent in animals, HFC-134a is oxidatively metabolized
following inhalation exposure as suggested by a slight increase in urinary fluoride levels. However, the rate of
metabolism of HFC-134a is very low and about 99 percent of an inhaled dose is eliminated unchanged.
In summary, HFC-134a has very low toxicity. The PAFTT (Level I) HFC-134a study has been completed.
The test results indicate that HFC-134
(1) has very low acute and subchronic inhalation toxicity
-------
(2) causes an increased incidence of benign, but not life-threatening, tumors in animals following
long-term exposure to high concentrations
(3) is not a developmental toxicant
(4) is not genotoxic
An exposure limit of 10<)0 ppm, 8-hour time-weighted average, has been recommended by the American
Industrial Hygiene Association, Workplace Environmental Exposure Limit (WEEL) Committee.
HCFC-142b: Toxicity information on HCFC142b (l-chloro-l,l-difluoroethane) has been reviewed by
Du Font's Haskell Laboratory (28) and by Scckar, Trochimowicz, and Hogan (29). HCFC-142b has a low order of
acute and subchronic inhalation toxicity. Weak anesthesia and slight cardiac sensitization to epinephrine are the
predominant health effects in animal exposure. The 4-hour approximate lethal concentration in rats is 400,000
ppm (40 percent). Acute inhalation at concentrations as high as 50,000 ppm sensitizes the heart to epinephrine in
dogs. When rats were exposed to HCFC-142b for 6 hours/day, 5 days/week for 104 weeks at several
concentrations, HCFC-142b was not carcinogenic and produced no significant toxic effects at any exposure level as
measured by mortality, body weight, hematology, clinical chemistry, urine analysis, and histopathological indices.
In vitro tests found that HCFC-142b was weakly mutagenic in several strains of bacteria. However, in vivo
inhalation studies in rats exposed for 90 days showed no mutagenic effects. Inhalation exposure in pregnant rats
showed that HCFC-142b is neither embryogenic nor teratogenic. One study investigated the metabolism of
HCFC-142b and found that little or no metabolism of this compound occurred, nor was it detected in any tissue
examined, indicating no long-term retention. Based on acute and chronic animal toxicity information, a threshold
limit value of 1000 ppm has been established.
HFC-143a: Du Pont's Haskell Laboratory has summarized the toxicity information on HFC-143a
(1,1,1 -Irifiuoroclhane) (30). HFC-143a has a low acute inhalation toxicity. None of the mice exposed acutely at
HFC-143a levels of 500,000 ppm died. It was not possible to establish a lethal concentration of the halocarbon
while maintaining normal oxygen levels of 18 to 20 percent. Chronic exposure of rats and guinea pigs to
200,000 ppm of HFC-143a (2 hours/day, 6 days/week for 4 weeks) revealed no behavioral changes, but a slight
tendency toward reduced body weight, a slight change in blood morphology (reduced hemoglobin level, reduced
erythrocyte count, and mild leukocytosis), and slight changes in liver and kidney function. Pathological
examination found mild bronchitis, interstitial pneumonia, and thickening of the alveolar septa. HFC-143a was
not carcinogenic in rats, when administered 300 mg/kg/day for 5 days/week for 52 weeks, followed by a 73-week
observation period. Although the compound was found to be a bacteria-specific mutagen, it did not exhibit
mutagenic properties in mammalian tests. Information on reprotoxicity, teratogenicity, and metabolism has not
been determined.
21
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HFC-152a: Toxicity testing oil HFC-152a (1,1-difluoroethane) indicates that it is one of the least toxic
halogenated hydrocarbons. Acute inhalation at concentrations as high as 40 percent docs not sensitize the heart to
epinephrine, nor does it induce arrhythmias when exposed without epinephrine to mice (31). At inhaled
concentrations as high as 20 percent, acute exposure produced no cardiovascular aberrations in anesthetized
monkeys (32) or dogs (33), but slightly increased the pulmonary resistance (34). HFC-152a administered to
anesthetized dogs at 10 to 20 percent concentrations caused depression in the force of myocardial contraction and
change in the ventricular function (24). Exposure to HFC-152a was found to increase the rate of mutation in
Drosophila melanogaster; however, it was inconclusive whether the mutagenesis was due to the halocaibon or a
response to anoxia (35).
FC-218: Generally, perfluorocarbons are thought to be relatively nontoxic. Accordingly, laboratory rats
and guinea pigs exposed to FC-218 showed few clinical signs of toxicity and all animals survived the exposure and
the observation period (36). In an extended study, a group of 20 rats and 20 guinea pigs was exposed for
24 hours/day for 10 days to 113,000 ppm. During the exposure no signs of toxicity were observed. Hematological
and pathological examination did not show any changes related to the chemical. Mutagenic studies in E. coli
showed mutants were obtained after a 24-hour exposure to FC-218. Developmental, reproductive, metabolic, and
carcinogenic studies have not been performed.
HFC-227ea: The acute inhalation toxicity of HFC-227ea is very low. The 4-hour LC^q in rats is greater
than 800,000 ppm with added oxygen. The cardiac sensitization in dogs was tested and it was determined that the
NOAEL and LOAEL were 9 and 10.5 percent, respectively.
FC-C318: The toxicity of FC-C318 (perfluorocyclobutane) has been studied extensively, since it has been
used as a food propellant (22). No signs of anesthesia or toxicity have been observed in 4-hour exposures in rats
and mice to FC-C318 levels as high as 80 percent in a mixture with 20 percent oxygen. Subchronic exposures of
10 percent FC-C318 (6 hours/day for 90 days) in rats, mice, rabbits, and dogs produced no harmful effects, as
determined by clinical examination, body weight, blood and urine tests, organ weights, and pathological
examination. Acute inhalation of 20 percent FC-C318 sensitizes the heart to epinephrine-induced arrhythmias in
anesthetized mice (24). In conscious dogs, however, a 50 percent level of FC-C318 was required to induce
arrhythmias (24), and at least 20 percent was needed to produce cardiovascular aberrations in anesthetized
monkeys (21). In monkeys, FC-C318 also causes an increase in pulmonary resistance but has no effect on minute
volume, heart rate, or blood pressure (37). FC-C318 administered to anesthetized dogs at a 20-percent
concentration caused depression in the force of myocardial contraction and change in the ventricular function (24),
Although the toxicity of neat FC-C318 is very low, a major concern is the possible formation of
unacceptable quantities of the supertoxic material perfluoroisobutylene (PFIB, (CF3)2C=CF2). PFIB has the same
molecular formula as FC-C318 (C4Fg), and there is evidence that FC-C318 can rearrange to form PFIB, both on
22
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prolonged storage and in flames. PFIB has a lclhal concentration several times lower than phosgene (38), a highly
toxic gas. The high toxicity of PFIB was demonstrated in a Russian study where an absolute lethal concentration
of0.0025 lo 0.0050 mg/L for rats and 0.0010 to 0.0025 mg/L for mice was found (39). In the same study,
pathological examination revealed that PFIB poisoning is characterized by acute vascular disorders of the internal
organs, particularly acute hyperemia and hemorrhages of the lungs and kidneys. The recommended occupational
exposure limit for PFIB is 10 ppb.
No studies appear to have been published on quantitative determination of the amounts of PFIB generated
in real-life fire scenarios. A pyrolysis experiment of FC-C318 in a 3-mm (1/8-inch) O.D. stainless steel tube
revealed that PFIB was formed as a decomposition byproduct ranging in concentration from zero to 0.221 mole
percent. The mean value observed for 13 trial runs was 0.043 mole percent with a standard deviation of 0.067
mole percent (40). Some cup-burner experiments have suggested that unacceptably high concentrations of PFIB
may be formed when perfluorocarbons having four or more carbon atoms enter flames. PFIB has also been
detected in samples of FC-C318 that had not been exposed to flames but had been stored for prolonged periods.
These results arc only preliminary, and a thorough investigation of the combustion byproducts of FC-C318 under
realistic fire scenarios would be desirable to determine exposure levels of firefighters to PFIB. The potential
formation of significant quantities of PFIB from FC-C318 does indicate that if FC-C318 is tested either alone or in
blends as a firefighting agents, monitoring for PFIB should be conducted and precautions including use of a self-
contained breathing apparatus (SCBA) should be taken at least until such time as the hazard can be assessed.
Gaseous substances that are highly toxic in very low concentrations often inactivate key enzymes. The
mechanism of toxic action of PFIB is not fully understood, but the presence of eight electron-withdrawing fluorine
atoms makes the central carbon atom a highly stabilized site for a carbanion. This suggests the possibility that
PFIB acts by alkylating an electron-rich site such as an oxygen or nitrogen atom at the active site of an enzyme
FC-3-1-10: Increasing fluorination in polyfluorinated butanes leads to a reduction in toxicity as it would
in polyfluorinated methanes, ethanes, and propanes. The series culminates with perfluorobulane (FC 3-1-10,
CF3CF2CF2CF3) being the least toxic halogenated butane. Rats exposed to 80 percent C4FJQ and 20 percent
oxygen for 4 hours showed only slight effects on respiration, but no pathological changes on any organs. No
deaths occurred at this concentration; therefore, the LC50 is greater than 80 percent. The cardiac sensitization
NOAEL of FC-3-1-10 in dogs given injected adrenaline was determined lo be greater than 40 percent in air. In a
2-wcck inhalation study, no adverse effects were observed at 10 percent in rats. No toxic signs were observed at
2.5, 5, or 10 percent in a 90-day inhalation study in rats.
23
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Availability and Cost
In order for a chemical to be tested fully and fielded in the near-term, it must be manufactured in bulk and
available in large amounts. The availability and cost of the chemicals on the PAA list (Table 2) were determined.
Chemicals were not eliminated from consideration based only on low expected fiiture bulk manufacture, for, in
general, based on the state of the art of organic synthesis and chemical engineering, it is expected that virtually any
one- to three-carbon haloalkane could be manufactured in bulk eventually. Even though, due to the unusual
properties of fluorinated compounds, the synthesis of fluoroalkanes is a specialized branch of organic chemistry,
numerous specialized reagents and techniques exist for the synthesis of fluoroalkanes (41 through 55). As is
normally the case in synthesis, certain molecules are much easier and less expensive to prepare than others.
The major producers of halocarbons include Allied-Signal, Alochem (which acquired Pennwalt in 1990),
Du Pont, Fluorochem, Great Lakes, Imperial Chemical Industries (ICI), La Roche, and Racon (56). Availability
and cost of PAAs are presented in Table 6,
Catalogs of manufacturers arc monitored on an ongoing basis to track the availability of halocarbons.
Chem Sources Online (a commercially available database) is also checked periodically. If attractive agents are
identified that have not been manufactured in bulk, applicable synthetic methods should be reviewed to determine
the feasibility of large-scale synthesis.
In addition, the agent should be able to be manufactured at an acceptable cost. Acceptable cost will
depend on the effectiveness and uniqueness of the agent. A highly cfTeetivc agent that could be used in small
quantities would be worth a higher price per pound than a moderately attractive, less expensive agent. It should be
noted that the new tax dictated by the Omnibus Budget Reconciliation Act of 1989 is $58.42/kg ($26.50/lb) in
1994 for Halon 1301 compared to its 1993 costof$11.57/kg($5.25/lb).
Materials Compatibililv
Two issues arise when discussing materials compatibility of alternative agents. The alternatives must be
compatible with materials in both the petroleum processing facilities and the storage and deliver}' fire/explosion
suppression systems. The North Slope facilities contain distinctive machinery and instruments; therefore,
information about the types of materials with which the chemicals must be compatible were assessed. Materials
compatibility is also an issue for transport, handling, and storage of the candidate agents. The agent must be
compatible with materials such as O-rings, valve seats, and metals used in extinguishing, oil handling, and aerosol
filling systems. Data are generally not available on materials compatibility except for specialized cases; for
24
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TABLE 6. AVAILABILITY OF PHYSICAL ACTION AGENTS
Halocarbon no.
Formula
Major supplier
Cost*
Comment
Halon 1301
CF3Br
Du Pont
$5.25/lb
Also other suppliers
(as reference)
14
cf4
PCR
$65/50g
Also other suppliers
22
CHC!F2
Service Supply Co.
$209/120lbs
Also other suppliers
23
chf3
Solkatronics
$1884/70lbs
Also other suppliers
32
ch2f2
PCR
$325/1 OOg
Also other suppliers
116
CF3CF3
Du Pont
$9.19/lb (95lbs)
Also other suppliers
124
CHCIFCF3
Allied Signal
NE
Also Du Pont
124
CHF2CCIF2
PCR
$108/25g
Also Fluorochem
125
chf2cf3
PCR
$120/50g
Also Du Pont
134
ch2fcf3
Du Pont
NE
Also other suppliers
134
chf2chf2
PCR
$95/1 OOg
Also other suppliers
142a
chcifch2f
None
N/A
N/A
142b
ccif2ch3
Autochem
$2.80/lb
Also other suppliers
143a
ch3cf3
Fairfield
$288/1 OOg
Also other suppliers
152a
chf2ch3
Du Pont
$2.47/lb
Also other suppliers
C216
OF 2CF 2CF 2
None
N/A
N/A
218
OF 3CF 2CF 3
MG Industries
$165/5lbs
Also other suppliers
226ba
CF3CCIFCHF2
None
N/A
N/A
227ca
cf3cf2cf2h
None
N/A
N/A
227ea
cf3chfcf3
Great Lakes
$50/lb
N/A
C234
CF2CF2CH2
None
N/A
N/A
235da
cf3chcichf2
None
N/A
N/A
235CC
ch2fcf2ccif2
None
N/A
N/A
235ca
CHF2CF2CHCIF
None
N/A
N/A
236cb
CH2FCF2CF3
None
N/A
N/A
236fa
cf3ch2cf3
PCR
$215/25g
N/A
244db
cf3chcich2f
None
N/A
N/A
244da
chf2chcichf2
None
N/A
N/A
244fb
ccif2ch2chf2
None
N/A
N/A
244bb
cf3ccifch3
None
N/A
N/A
244ca
chf2cf2h2ci
None
N/A
N/A
244cb
ch2fcf2chcif
None
N/A
N/A
245cb
cf3cf2ch3
PCR
$195/10g
Also Fluorochem
245ea
chf2chfchf2
None
N/A
N/A
245eb
cf3chfch2f
None
N/A
N/A
245ca
chf2cf2ch2f
None
N/A
N/A
254ea
chf2chfch2f
None
N/A
N/A
254cb
CHF2CF2CH3
None
N/A
N/A
254eb
cf3chfch3
None
N/A
N/A
254fa
CHF2CH2CHF2
None
N/A
N/A
254ca
CH2FCF2CH2F
None
N/A
N/A
3-1-10
C4F10
3M Chemicals
$20/lb
Also other suppliers
C318
Linde
$280/1b
Also other suppliers
* Cost as of 1 January 1993.
N/A = not available
25
-------
example, the compatibility of HCFC-123 (CHC12CF3) with elastomers, wiring coatings, and various plastics has
been investigated by Du Pont. Most other chemicals do not have compatibility information.
Because agents arc often stored for prolonged periods, long-term compatibility with materials used in
extinguishing systems must be satisfactory. Corrosion of metal surfaces must be minimal. Compatibility with
materials to which the agent is applied during fires, or which may be exposed to the agent during false dumps,
should also be considered. For example, the agent should have low electrical conductivity to avoid shorting
electrical equipment Since organic liquids in general, and halogenatcd hydrocarbons in particular, have very low
electrical conductivity, electrical conduction is not expected to occur
Since, in general, it is expected that materials compatible with a particular halocarbon can be found, it is
anticipated that materials compatibility will be investigated only after a small group of attractive agents has been
identified based on the other criteria described elsewhere in this report. Once these agents have been identified,
testing to determine their compatibility with structural and engineering materials, such as O-rings and valve scats,
will need to be conducted. Relevant test methods may include fluid resistance of gasket materials (ASTM F 146-
84), hardness (ASTM D 1415-83), effects of liquids (ASTM D 471-479), change in length during liquid
immersion (ASTM D 1460-81), and physical properties of O-rings (ASTM D 1414-78), and/or the compatibility
screens described by the National Institute of Standards and Technology (NIST) (57).
Knowledge of the corrosion of metals is important with respect to both agent storage and formation of
decomposition byproducts, in both the absence and presence of water. Tests under both normal and accelerated
(elevated temperature and/or pressure) conditions will need to be conducted. Tests of the corrosiveness of
halogenatcd organic solvents and mixtures on metals (ASTM D 2251), laboratory immersion corrosion testing of
metals (ASTM G 31-72), and the examination and evaluation of pitting corrosion (ASTM G 46-76) may be
required. Again, the NIST tests on metal corrosiveness may be considered (57).
Cleanliness
Agent cleanliness is an important criterion for certain applications. Cleanliness is defined as the ability to
evaporate rapidly without leaving residue harmful to electronic or other equipment. One of the major advantages
of the currently used halons is their cleanliness. They can be used on electronic, electrical, or complex mechanical
equipment without requiring subsequent cleanup or causing equipment malfunction.
All halocarbons with BPs below 50 °C that do not contain high-boiling impurities are expected to be
clean. Meeting the cleanliness criterion is not expected lobe a problem for any of the agents considered herein.
26
-------
Flame Suppression
For a fire extinguishaiit to be effective, contributions of both physical and chemical mechanisms should be
optimized. Physical extinguishment includes contributions from heat of vaporization, vapor specific heat, and
heats of reaction (e.g., heats of combustion and decomposition). Chemical extinguishment involves disruption of
the radical chain reactions occurring in fires. The agent (neat or blends) must be effective in suppressing
hydrocarbon fuel and hydraulic fluid explosions and fires; it should not be flammable at any concentration in air.
Fire suppression depends on both chemical and physical median isms. The primary chemical mechanism
for halons and halon-like suppressants involves the termination of radical reactions that sustain combustion.
Bromine-substituted compounds are particularly effective in this role. However, other halogenated compounds
exhibit fire suppression capabilities. For a comprehensive discussion of extinguishment mechanisms, the reader is
directed to References 58 and 59.
Studies indicate that compounds containing CF3 groups have anomalously low extinguishing
concentrations. Results from recent work at the Naval Research Laboratory (59), as well as C.GET/NMERI
laboratory results, indicate that the CF3 group has a relatively high effectiveness in fire extinguishment. Thus,
compounds such as FC-116 (CF3CF3), FC-218 (CF3CF2CF3), and FC-125 (CHF2CF3) are more effective than
calculations from fire extinguishment algorithms—not accounting for the presence of CF3 groups—would indicate.
The following reactions may be involved in flame extinguishment by CF3 in flames, where M is any third body that
can absorb excess energy such as other molecules or the container:
Physical mechanisms of extinguishment include heat removal and dilution of fuel and oxygen. Oxygen
and gaseous fuel dilution appear to play a very minor role in extinguishment by halocarbons, as can be seen in the
high fire extinguishment concentration (above 20 percent) required by carbon dioxide, which operates primarily by
dilution. In comparison, halocarbons usually have extinguishment concentrations well below 20 percent.
However, other physical mechanisms arc important in extinguishment by halons and oilier halocarbons. First, the
molecules can carry off energy (remove heat) by excitation of rotational, vibrational, and translational molecular
motions: greater rotational and vibrational energies are possible in larger molecules. Energy removal occurs
during both agent evaporation and agent heating. Second, the molecules can dissociate thermally while absorbing
energy. Both of these processes lower the temperature of the fire.
CF3 + H + M -> HCF3 + M*
[51
CF, + OH HOCFj COF2 + HF
[6]
27
-------
In addilion, it has been proposed that halons lave a lire suppression mechanism that is not clearly
physical or chemical. Their molecules can act as third bodies to absorb energy, thus facilitating recombination of
other radicals (60).
Depending on the application, the effectiveness of agents should be considered on a pcr-wcight and per-
liquid-volume basis, as well as on the basis of flame extinguishment concentrations (reported on a per-gas-volume
basis). For the North Slope application, volume is a critical limiting factor. It is desirable that the volume of agent
required be less than or equal to that of the currently used Halon 1301, so that larger storage cylinders are not
needed. Nonetheless, an agent that requires a much higher gas volume (and molar) concentration than Halon 1301
for flame extinguishment in the laboratory cup burner could still be attractive if extinguishment requires only a low
weight or liquid volume.
One can predict extinguishment concentrations by fitting an equation first reported by Hirst and Booth to
known extinguishment concentrations (58). This algorithm estimates the fire suppression concentrations of
haloalkanes based on their molecular formulas. The algorithm model PREDICT (61), has been used to predict the
fire suppression concentration for the compounds in the NMERI HALOCARBON DATABASE® without
measured values.
The predictive algorithm employs a parameterized fit to the molecular formula using regression
techniques. The formula is as follows:
Log F = - A • LOG # (B * nF + C ~ nc| + D * n^) + E
where
F = extinguishing concentration required for a hexane fire
nF = number of fluorine atoms
i^i = number of chlorine atoms
nI5r = number of bromine atoms
and the best fit values for the parameters are A = 0.811;B= 0.685; C = 2.953; D = 12.350; and E = 1.558.
The formula predicts the concentration necessary to extinguish flames in a cup burner using hexane fuel.
Data from literature searches were used to determine a baseline of extinguishing concentrations. The model fits
11 experimental data points with R2 = 0.941. When applied to other halocarbons, it predicts extinguishing
concentrations that agree well with measured values in most cases. Discrepancies appear to occur when CF3
28
-------
groups can be generated in the reaction. This model is being modified as additional data are obtained; therefore,
no chemical was rejected based solely on predicted or reported extinguishment concentrations. Measured or
predicted flame suppression concentrations were listed in Table 3 with physical property information.
Volume 2 of this effort presents the cup-burncr extinguishment concentration and hemispherical bomb
inertion concentrations of candidates recommended for laboratory-scale testing from this phase of the project.
Environmental Considerations
Information on environmental considerations was collected on the candidates. Data on ODP, GWP, and
atmospheric lifetimes were collected when possible or estimated if information was not available. ODPs and
GWPs have been estimated from measured hydroxyl reaction rates and absorption cross sections without use of
atmospheric modeling (62). CGET/HMERI has been able to estimate ODPs with a good fit (R^ = 0.70 for
17 compounds with reported rigorously calculated ODPs) based only on molecular structure (62). Collaborative
work is underway between CGET/NMER1 and Lawrence Livermore National Laboratories (LLNL) to obtain
rigorously calculated ODPs for additional compounds to refine this estimation procedure. Predicted values will be
updated as information becomes available.
Ozone Depletion Potential (ODP)~
Thc Ozone Depletion Potential (ODP) is a number that gives the calculated relative extent to which a
particular chemical compound depletes stratospheric ozone on a pcr-molcculc or per-pound emitted basis. The
more commonly used per-pound basis is also used in this report. ODPs are rigorously calculated using
atmospheric models. CFC-11 has been arbitrarily assigned an ODP of 1.0. Higher numbers indicate a greater
potential to deplete stratospheric ozone. No standard target for the ODP of PAAs has been agreed upon by all
nations; however, to meet the 1990 amendments to the US Clean Air Act. the agent must have an ODP of 0.2 or
less if manufacture after the year 2000 is to be ensured. Table 7 includes a list of ODPs for selected candidates
from Reference 63,
Present halon firefighting agents have high ODPs because they are inert to tropospheric degradation, thus
generating bromine radicals in the stratosphere (64 through 67). As a class, the existing halons have ODPs
ranging from approximately 3 to 10. Other types of halocarbons (CFCs, HFCs, HCFCs, and FCs) have lower
ODPs because chlorine is less destructive to ozone than is bromine, and fluorine causes no ozone depletion.
Moreover, halocarbons containing one or more hydrogen atoms are subject to destruction by hydroxyl
radicals in the atmosphere before they can reach the stratosphere. Therefore, alternative halocarbon agents
containing either bromine or chlorine must also include at least one hydrogen atom to obtain a decreased ODP. It
29
-------
TABLE 7. ATMOSPHERIC LIFETIMES, ODPS. AND GWPS OF PHYSICAL ACTION AGENTS
Halocarbori no.
Formula
Atmospheric life (yrs)
Ozone depletion
potential (relative to
CFC=1.0)
Global warming
(relative to CFC-
Halon 1301 (as
CF3Br
110
10
2.0
reference)
14
cf4
500
0
Value unknown
22
chcif2
14.2
0.05
0.35
23
chf3
411
0
Value unknown
31
ch2cif
1.35
001
Value unknown
32
ch2f2
6.72
0
Value unknown
116
CF3CF3
500
0
Value unknown
124
CHCIFCF3
6
0.019
0.25
124a
CHF2CCIF2
34 (estimated)
0.04 (estimated)
Value unknown
125
chf2cf3
26.4
0
0.58
134
chf2chf2
11.4
0
Value unknown
134a
ChUFCFg
14.4
0
0.27
142a
chcifch2f
0.85 (estimated)
0.03 (estimated)
Value unknown
142b
ccif2ch3
17.9
0.053
0.36
143a
ch3cf3
39.5
0
0.74
152a
chf2ch3
0.6
0
0.03
C216
cf2cf2cf2
Value unknown
0
Value unknown
218
cf3cf2cf3
Value unknown
0
Value unknown
226ba
cf3ccifchf2
Value unknown
0.03 (estimated)
Value unknown
227ca
cf3cf2cf2h
Value unknown
0
Value unknown
227ea
cf3chfcf^
30.0
0
Value unknown
C234
cf2cf2ch2
Value unknown
0
Value unknown
235da
cf3chcichf2
Value unknown
0.03 (estimated)
Value unknown
235cc
ch2fcf2ccif2
Value unknown
0.03 (estimated)
Value unknown
235ca
chf2cf2chcif
Value unknown
0,03 (estimated)
Value unknown
235ba
chf2ccifchf2
Value unknown
0.03 (estimated)
Value unknown
235eb
chf2chfccif2
Value unknown
0.03 (estimated)
Value unknown
235ea
cf3chfchcif
Value unknown
0.03 (estimated)
Value unknown
235bb
cf3ccifch2f
Value unknown
0 03 (estimated)
Value unknown
236cb
ch2fcf2cf3
Value unknown
0
Value unknown
236fa
cf3ch2cf3
6.4
0
Value unknown
244db
cf3chcich2f
Value unknown
0 03 (estimated)
Value unknown
244da
chf2chcichf2
Value unknown
0.03 (estimated)
Value unknown
244fb
ccif2ch2chf2
Value unknown
0.03 (estimated)
Value unknown
244bb
cf3ccifch3
Value unknown
0.03 (estimated)
Value unknown
244ca
chf2cf2ch2ci
Value unknown
0.03 (estimated)
Value unknown
244cb
ch2fcf2chcif
Value unknown
0.03 (estimated)
Value unknown
244ba
CHF2CcfrcH2F
Value unknown
0.03 (estimated)
Value unknown
244ea
chf2chfchcif
Value unknown
0.03 (estimated)
Value unknown
244eb
cf3chfch2ci
Value unknown
0.03 (estimated)
Value unknown
244fa
cf3ch2chcif
Value unknown
0.03 (estimated)
Value unknown
244ec
ccif2chfch2f
Value unknown
0.03 (estimated)
Value unknown
245cb
cf3cf2ch3
Value unknown
Value unknown
245ea
chf2chfchf2
Value unknown
0
Value unknown
245eb
cf3chfch2f
Value unknown
0
Value unknown
245ca
chf2cf2ch2f
Value unknown
0
Value unknown
254ea
CHFjCHFCh^F
Value unknown
0
Value unknown
254cb
chf2cf2ch3
Value unknown
0
Value unknown
254eb
cf3chfch3
Value unknown
0
Value unknown
254fa
chf2ch2chf2
Value unknown
0
Value unknown
254ca
CH,FCFoCH9F
Value unknown
0
Value unknown
3-1-10
c4*|0
Value unknown
0
Value unknown
C318
C4F8
Value unknown
0
Value unknown
30
-------
is important that this hydrogen atom be weakly bonded and accessible for removal by hydroxyl radicals in the
troposphere. Another possibility is the development of agents that contain functional groups, such as double bonds
or geminal dibromidc groups, that result in their rapid destruction in the troposphere by oxidation or photolysis.
FCs and HFCs have zero ODPs, since they do not generate ozone-destroying chlorine or bromine radicals.
Global Wanning Potential (GWP)~
The GWP is a number that gives the calculated relative extent to which a particular chemical compound
contributes to global warming on a per-pound emitted basis. GWPs are rigorously calculated using atmospheric
models. CFC-11 is arbitrarily assigned a GWP of 1.0. Higher numbers indicate a greater potential to contribute to
global wanning. The GWP of a PAA should be as close to zero as possible.
Although no legislation has gone into effect mandating a limit to GWP, the greenhouse effect or global
warming caused by the presence of halocarbons is receiving increasing attention (68 and 69). This effect may
prove equal in importance to ozone depletion as an environmental hazard. Existing halons and CFCs have GWPs
ranging up to several thousand times that of carbon dioxide on a pcr-pound-emitted basis (70, 71, and 72).
The greenhouse effect is caused by the absorbance and emission of infrared light in the "atmospheric
window" (the 7 to 14 800 to 1400 cm-1 region) by trace atmospheric components. Molecules containing
carbon-to-halogen bonds (C-F, C-Cl, C-Br) absorb and re-emit infrared radiation in this region, causing energy
that would otherwise have been lost into space to be redirected toward the earth. Temperature sensitivity is a
measure of how much the temperature of a body of air increases for every part per billion by volume (ppbv) of an
organic present. GWP takes into account both this temperature sensitivity and atmospheric lifetime. On a per-
molecule basis, some halocarbons, such as Halons 1301 and 1211, have temperature sensitivities 25,000 times that
of carbon dioxide. Tabic 7 includes GWPs for selected agents.
One approach to reducing GWP as with ODP is to minimize atmospheric lifetime, for example, by
including hydrogen atoms or multiple bonds in the chemical structure of the compound. Another approach is to
minimize absorption of infrared radiation by appropriate design of the chemical structure.
Both ODPs and GWPs depend on atmospheric lifetimes. For ODP, a longer lifetime means a greater
proportion of the molecules released reaches the stratosphere, where photolysis creates the chlorine or bromine
radicals that catalyze destruction of ozone. With respect to global wanning, a longer lifetime means the molecules
are absorbing infrared light radiated by the surface of the earth and transforming it to kinetic energy for a longer
time, resulting in increased wanning; therefore, it is desirable that alternative agents have short atmospheric
lifetimes. Table 7 presents atmospheric lifetimes for selected alternative chemicals.
31
-------
SECTION 3
CHEMICAL ACTION AGENTS
INITIAL CHEMICAL SELECTION
Screening of all families of halocarbons was not performed in this task; rather a select number of
chemicals from the hydrobromofluorocarbon, fluoroidocarbon, haloether, and haloalkene families were the focus of
the study and were used as model compounds for the entire chemical family. Chemicals that had been previously
surveyed and those discovered in the process of the limited survey were the focus of this investigation As
information was being gathered on the selected candidates from the above-mentioned families, additional
chemicals were identified as possible candidates and were also considered as possible replacements. Table 8
presents the chemical action agents developed as the initial chemical list.
Boiling poinl was not used as a selection criterion for total-flood agents in this effort as has been done in
the past. Instead, a number of CAAs from the four families of chemicals mentioned above were used as model
compounds in order to gain general information about the particular class of chemicals. Since most of the
chemicals identified had boiling points well above 0 °C, it was recognized that these candidates would likely
require an alternative mechanism such as misting in order to disperse the chemicals in a total-flood capacity.
Nonetheless, these candidates were considered because they provided useful information about the family as a
whole and increased the number of possible candidate agents.
SELECTION CRITERIA
Available information on the initial list of CAAs was collected, compiled, and assessed. Sources of
information included the open literature, on-line databases, and industry contacts. Information was collected on
physical properties, toxicity, availability and cost, and environmental characteristics. Regulatory concerns are
presented in Appendix B. Based on an assessment of these parameters several candidate agents were selected and
tested in the laboratory-scale cup-burner and explosion sphere apparatuses. These data are presented in Volume 2
of this series (1). The results of the laboratory testing led to recommendations (Section 4) as to which chemicals
(and chemicals classes) should be further studied.
Physical Properties
The effectiveness of an explosion or fire suppression agent in actual, large-scale fires depends upon agent
deliverability, heat removal capability, and radical reaction termination capability. The physical properties to be
considered when determining the potential of a chemical for total-flood applications include, but are not limited to
32
-------
TABLE 8. LIST OF CHEMICAL ACTION AGENTS
Name
Formula
CAS no.
HYDROBROMOFLUOROCARBONS
Dibromofluoromethane
1,2-Dibromo-1,1,2-trifluoroethane
2.2-Dibromo-1,1,1 -trifluoroethane
2.3-Dibromo-1,1,1 -trifluoropropane
Bromodifluoromethane
2-Bromo-1,1,1,2-tetrafluoroethane
FLUOROIODOCARBONS
T rifluoroiodomethane
Difluoroiodomethane
Fluoroiodomethane
Pentafluoroiodoethane
Perfluoro-n-propyl iodide
Perfluoroisopropyl iodide
Perfluoro-n-butyl iodide
Perfluoro-n-hexyl iodide
Perfluoro-n-octyl iodide
HALOETHERS
Perfluorodimethyl ether
Methyl Trifluoromethyl ether
Difluoromethyl fluoromethyl ether
1,1,2,2-Tetrafluorodl-methyl ether
Trifluoromethyl difluoromethyl ether
Trifluoromethyl pentafluoroethyl ether
Perfluorooxetane
1,1,2,2-Tetrafluoroethyl difluoromethyl ether
1,1,1-Trifluoroisopropyl trifluoromethyl ether
1,1,1-Trifluoroethyl difluoromethyl ether
1,1-Difluoroethyl fluoromethyl ether
Perfluorodimethoxymethane
Difluoromethyl bromodifluoromethyl ether
Trifluoromethyl bromodifluoromethyl ether
Difluoromethyl bromotetrafluoroethyl ether
Methyl bromodifluoromethyl ether
BROMOFLUOROALKENES
CHBr2F
CBrF2CHBrF
CHBr2CF3
CF3CHBrCH2Br
CHBrF2
CF3CHBrF
CF3I
CHF2I
ch2fi
cf3cf2i
CF3CF2CF2I
CF3CFICF3
CF3CF2CF2CF2I
CF3(CF2)4CF2I
CF3(CF2)6CF2l
CF3OCF3
CH3OCF3
CHF2OCH2F
CHF2OCHF2
CF3OCHF2
CF3OCF2CHF2
-CF2CF2CF2O-
CHF2OCF2CHF2
CF3(CH3)CHOCF3
CF3CH2OCHF2
CHF2CH2OCH2F
CF3OCF2OCF3
CHF20CBrF2
CF30CBrF2
CHF20CF2CBrF2
CH3OCBrF2
1858-53-7
354-04-1
354-30-3
431-21-0
1511-62-2
124-72-1
2314-97-8
1493-3-4
373-53-5
354-64-3
754-34-7
677-69-0
423-39-2
355-43-1
507-63-1
1479-49-8
421-14-7
461-63-2
1691-17-1
3822-68-2
2356-61-8
425-82-1
32778-11-3
32793-58-1
1885-48-9
None
53772-78-4
None
None
32778-13-5
None
3-Bromo-3,3-difluoropropene
3-(Bromodifluoromethyl)-3,4!4,4-tetrafluoro-1-butene
2-Bromo-3,3,3-trifluoro-1-propene
4-Bromo-3,3,4,4-tetrafluoro-1-butene
2,3-Dibromo-3,3-difluoro-1-propene
4-Bromo-3-chloro-3,4,4-trlfluoro-1-butene
1,2-Dibromo-3,3,3-trifluoro-1-propene
3-Bromo-1,1,3,3-tetrafluoro-1-propene
1-Bromo-3,3,3-trifluoro-1-propene
CH2=CHCBrF2
CH2=CHC(CBrF2)FCF3
CH2=CBrCF3
CH2=CHCF2CBrF2
CH2=CBrCBrF2
CH2=CHCCIFCBrF2
BrCH=CBrCF3
CF2=CHCBrF2
BrCH=CHCF3
420-90-6
2546-54-5
1514-82-5
18599-22-9
677-35-0
374-25-4
431-22-1
460-61-7
460-33-3
33
-------
the following: boiling point; melting (freezing) point; vapor heat capacity; heat of vaporization; vapor pressure (at
room temperature); heat of reaction to form products of CO^ and HX (where X refers to a halogen) using H2O as
an oxygen and hydrogen source; viscosity; and vapor and liquid density. Some properties relate primarily to
dcliverability (e.g., boiling point, vapor density, viscosity, and vapor pressure) and some to extinguishing ability
(e.g., vapor specific heat and heat of vaporization). Physical properties arc not available for many of the potential
candidates. For compounds that appear particularly promising but for which important physical properties arc
needed, those properties must be determined in the laboratory. Table 9 presents selected physical properties for the
initial list of CAAs.
A traditional total-flood agent should have a boiling point that allows it to be delivered as a gas. Those
chemicals in Table 8 that have high boiling points (> 20-30 °C) will probably not disperse effectively from typical
total-flood systems; therefore, alternative dispensing mechanisms will need to be investigated for use with these
agents. In addition, the vapor pressure at room temperature should be adequate for rapid dispersal, but not so high
as to require expensive and complex high pressure equipment. Most of the candidate agents having known vapor
pressures are below that of Halon 1301. Stored agents in cylinders are in the liquid state if the storage pressure is
greater than the vapor pressure of die agent. Normally, halons are stored as liquids, since agent storage pressures
are on the order of 200-300 psi.
For effective heat removal, an agent should have high vapor specific heat and high heat of vaporization.
Ideally, the vapor specific heat should be equal to or higher than that of the existing agents (69.2 J/mol-K for
Halon 1301), as should the heat of vaporization (17,693 J/mol for Halon 1301). Only three candidates have known
vapor specific heat. The vapor specific heat for bromodifluoromethane is lower than that of Halon 1301, but not
significantly. The other two (bromodifluoromethane and trifluorometlianc) have specific heat values near Halon
1301. All CAAs with known heats of vaporization are above the value for Halon 1301.
The freezing (melting) point of the agent should preferably be below -60 °C. Under normal use (indoors)
at the North Slope, the agent should not experience temperatures below 0 °C; however, agent cylinders being
transported outdoors during winter could conceivably be exposed to temperatures as low as -60 °C. Organic
liquids normally contract upon solidification. Thus, even if the agent solidifies briefly, it is not expected to exert
high pressures against the containment walls or valves; upon rewarming to ambient temperature the cylinder is
expected to behave normally. The known melting points of agents on the potential candidate list arc all below
-60 °C.
Chemicals with low molecular weights and high densities are attractive replacement agents.
Unfortunately, most CAAs considered herein contain either bromine or iodine and therefore have higher molecular
weights and higher liquid densities than Halon 1301. This means that on a weight equivalent basis, even an
extremely effective fire suppressant may not be attractive since it could require a higher mass to provide the same
34
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TABLE 9. SELECTED PHYSICAL PROPERTIES OF CHEMICAL ACTION AGENTS
Name
Formula
Molecular
weight
(cj/mol)
Boiling
point
CO
Melting
point
CC)
Vapor specific
heat
(J/moi-K)
Heat of
vaporization
(J/mol)
Vapor
pressure1'*
(psia)
Liquid
(ofcrr&
Halon 1301 (as reference)
CBrF3
148.9
-57
168
69.2
17,693
94.7
1.57
HYDROBROMOFIUOROCARBONS
Dibromofluorom ethane
CHBr?F
191.81
64.5
N/A
65.15
26,778
N/A
2.421 (20 °C)
1,2-Dibromo-1,1,2-trifluoroethane
CBrF2CHBrF
241.82
73
N/A
N/A
N/A
N/A
2.165
2,2-Oibromo-1,1,1 -trifluocoethane
CHBr2CF3
241.82
73
N/A
N/A
N/A
N/A
222
2,3-Dibromo-1,1,1 -triftuoropropane
CF3CHBrCH2Br
255.85
116
N/A
N/A
N/A
N/A
2.12
Bromodifluoro methane
CHBrF2
130.9
-15.5
-145
57.7
19,246
54.7(20 °C)
1.55
2-Bromo-1,1,1,2-tetrafiuoroethane
CF3CHBrF
180.92
9
N/A
N/A
N/A
N/A
1.85
FLUOROIODOCARBONS
T rifluoroiodomethane
CF3I
195.91
-23
N/A
70.7
22,414
872
236
D ifluoroiod ometha ne
CHF2I
177.9
22
-122
N/A
25,989
17.7
2.296
Fluoroiodomethane
CH2FI
159.9
52
N/A
N/A
N/A
N/A
2.36
Pentaftuoroiodoethane
CF3CF2I
245.91
13
N/A
N/A
N/A
23.6
2.07
Perfluoro-n-propyl iodide
CF3CF2CF2I
295.92
41
-95.3
N/A
N/A
N/A
2.06
Perfluoroisopropyl iodide
CF3CFICF3
295.92
40
N/A
N/A
N/A
3.04(20 =C)
2.099(20 °C)
Perfluoro-n-butyt iodide
CF3CF2CF2CF2I
345.92
67
N/A
N/A
N/A
N/A
2.01(20 °C)
Perfluoro-n-hexyl iodide
CF3(CF2)4CF2I
445.94
117
N/A
N/A
N/A
N/A
2.05(20 °C)
Perfluoro-n-octyt iodide
CF3(CF2)6CF2l
545.95
1605
N/A
N/A
N/A
N/A
2.04
HALOETHERS
Perfluorodimethyl ether
CF3OCF3
154.01
-59
N/A
N/A
N/A
N/A
N/A
Methyl trifluoromethyl ether
CH3OCF3
100.04
-24
-149
N/A
21,580
72.2
N/A
(continued)
-------
TABLE 9. (concluded)
Name
Formula
Molecular
weight
(g/mol)
Boiling
point
CC)
Melting
point
CC)
Vapor specific
heat
(J/mol-K)
Heat of
vaporization
(J/mol)
Vapor
pressure'1*
(psia)
Liquid
density'
(0/om3)
Difluoromethyl ft uorom ethyl ethef
CHF22F
100.04
30.1
-96.2
N/A
29,266
N/A
1.328
1,1,2,2-Tetrafluoro-dimettiyl ether
CHF2OCHF2
118.03
4.7
N/A
N/A
N/A
N/A
N/A
Trifluoromethyl diflixxomethyl ether
CF3OCHF2
136.02
-34.5
-156
N/A
21,799
113.4
1.275
Trifluoromethyl perrtafluoroethyl ether
CF3OCF2CHF2
186.03
-4.2
-141
N/A
26,192
40 3
i^s-c)
Perfluorooxetane
-CF2CF2CF2O-
166.02
-28.4
-117
N/A
22,301
63.5(20 °C)
1.349(30)
1,1,2.2-Tetrafluoroethyt difluoromethyl ether
CHF2OCF2CHF2
168.03
28.5
N/A
N/A
N/A
N/A
N/A
1,1,1 -Trifluoroisopropyl trifluoromethyl ether
CF3(CH3)CHOCF3
182.07
27
N/A
N/A
N/A
N/A
N/A
1,1,1 -Trifluoroethyl difluoromethyl ether
CF3CH2OCHF2
150.06
29
N/A
N/A
N/A
N/A
N/A
1,1 -Difluoroethyl fluoromethyl ether
CHF2CH2OCH2F
114.07
N/A
N/A
N/A
N/A
N/A
N/A
Perfluorodimethoxymethane
CF3OCF2OCF3
236.01
-10
-161
N/A
23891
52.3(20 °C)
N/A
Difluoromethyl bromodifluoromethyl ether
CHF2OCBrF2
214.99
24.6
N/A
N/A
N/A
N/A
N/A
Trifluoromethyl bromodifluoromethyl ether
CF30CBrF2
214.91
-5.4
N/A
N/A
N/A
N/A
N/A
Difluoromethyt bromotetrafluoroethyl ether
CHF20CF2CBrF2
246 93
45
N/A
N/A
N/A
N/A
N/A
Methyl bromodifluoromethyl ether
CH30CBrF2
160.94
N/A
N/A
N/A
N/A
N/A
BROMOFLUOROALKENES
3-Bromo-3,3-difluoropropene
CH2=CHCBrF2
156.95
42
N/A
N/A
N/A
N/A
1.54
3-(Bromodifkioromethy1)-3,4,4.4-
CH2=CHC(CBrF2)FCF3
256.97
79.5
N/A
N/A
N/A
N/A
1.67(21 °C)
tetrafluoro-1 -butene
2-Bromo-3,3,3-trifluoro-1 -propene
CH2=CBrCF3
174.94
34.5
N/A
N/A
N/A
N/A
N/A
4- B romo-3,3,4,4-tetrafl uoro-1 -butene
CH2=CHCF2CBrF2
206 96
55
N/A
N/A
N/A
N/A
1.357
2,3-Dibromo-3,3-difluoro-1 -propene
CH2=CBrCBrF2
235 84
100
N/A
N/A
N/A
N/A
N/A
4-Bromo-3-chloro-3,4,4-trifluoro-1 -butene
CH2=CHCQFCBrF2
223 40
99.5
N/A
N/A
N/A
N/A
1.678
1,2-Dibrom 0-3,3,3-tnfluoro-1 -propene
BrCH=CBrCF3
253.80
96
N/A
N/A
N/A
N/A
N/A
3-Bromo-1,1,3,3-tetrafluoro-1 -propene
CF2=CHCBrF2
192 93
35
N/A
N/A
N/A
N/A
1.75
1-Bromo-3,3,3-trifluoro-1-propene
BrCH=CHCF3
174,94
33
N/A
N/A
N/A
N/A
1.65
*Data taken from the NMERI Halocarbon Diabase® (3).
'25 °C unless otherwise stated in parentheses,
JResutts are given in psia; conversion to metric: 1 psi = 6.894 kPa.
N/A=Not available.
-------
gas-volume concentration as Halon 1301. However, on a storage volume basis, the candidate may appear more
effective because of the high liquid densities. Weight equivalency is important because users normally purchase
agent by the pound. If an agent has a higher weight equivalency, more pounds of agent are required to provide the
same protection as Halon 1301 provides. Storage volume equivalency is also important because it indicates how
much more storage volume will be required to effect the same protection as Halon 1301, Storage volume and
weight equivalences will be discussed in more detail in Volume 2 (1).
Toxicity
A key criterion for determining the potential of halon replacement candidates is the impact on human
health. In fact, it is unlawful under the Significant New Alternatives Policy (SNAP) to replace halons with any
substitute that may have a negative impact on human health. This statement indicates that toxicological
considerations are major concerns when developing halon replacement agents. Ideally, a replacement agent should
be no more toxic than the currently-used halons. Halon 1301 has a very low toxicity; therefore, developing a
replacement that equals this low toxicity level may prove to be the most difficult challenge in finding an effective
candidate. In addition, toxicity testing is the most time-consuming and expensive effort in the development of a
halon replacement. Estimates indicate that the cost range for the battery of toxicity tests required to satisfy
regulatory and liability issues is $2-5 million per chemical (73).
A number of toxicity tests have been suggested for halon replacement agents to facilitate a risk assessment
decision. Below is the list of likely toxicity7 tests required by EPA for fire extinguishing agents under the SNAP
program (74):
• Range finder of acute toxicity (such as an LCjo test)
• 4- or 13-week subchronic test
• Developmental toxicity test
• Cardiac sensitization test
• Degradation byproduct tests (not combustion toxicology)
Another test that might be required, as determined on a casc-by-case basis, is one to determine the
exposure concentration during the specific use of a replacement agent. Most of the tests listed above determine the
toxicity due to short exposures. However, other longer exposure tests would likely be required to satisfy concerns
imposed during manufacture of the chemical and maintenance and service of the extinguisher systems.
Since low toxicity is extremely important for total-flood applications in potentially inhabited areas, it is
essential that already known toxicity information be assessed carefully. Such an assessment is needed to avoid
expenditures of time or money for future toxicity testing of compounds that could not ultimately be used. To assess
37
-------
accurately llic toxic potentials of the chemical action agents, already available toxicity information on those listed
in Table 8 was collected and evaluated. The information was retrieved through on-line computer searches of
toxicological databases such as Toxlit, Toxline. and Chemical Abstract Services, manual searches, and in certain
circumstances by collecting unpublished information from industry contacts. For many chemicals, little, if any,
toxicity information was available.
Several key long- and short-term biological responses occur from exposure to halocarbons. These effects
include the following: (1) central nervous system (CNS) depression of stimulation depending on the chemical,
symptoms range from lethargy and unconsciousness to tremors and convulsions; (2) sensitization of the heart to
adrenalin causing potentially life-threatening cardiac arrhythmias; (3) respiratory system dysfunction involving
bronchioconstriction, reduced pulmonary compliance, depressed respiratory volume, reduced blood pressure, and
tachycardia; (4) hepatotoxicity and other organ damage due usually to products of metabolism; (5) reproductive
effects, either teratogencsis or reproductive dysfunction; and (6) cancer or mutagenesis. CNS effects, cardiac
sensitization, and respiratory dysfunction are generally considered to be immediate effects that are reversible after
the exposure is terminated, if the exposure was not massive enough to cause death. On the other hand, organ
damage, reproductive effects, cancer, and mutagenicity are latent, irreversible effects, and delayed consequences
are usual.
Hydrobromofluorocarbons—
The toxicological properties of HBFCs are similar to those mentioned above for fluorocarbons in general.
The substitution of either fluorine or chlorine with bromine normally increases the toxicity of the resulting
chemical. In addition, having more than one bromine atom on a molecule apparently dramatically increases the
toxic properties, in particular the anesthetic potency. For example, the LCjo and ADjo for CFjCHjBr are 11.7 and
2.8 percent, respectively (22). The LCjo and AD50 for CFjCHBrj are 2 and 0.4 percent, respectively. The
addition of a second bromine atom significantly increased both the lethal and anesthetic potentials of the
compound.
The most widely investigated brominated compound is halothane (CF3CHBrCl). The interest in the
chemical is generated by its wide use as a clinical and veterinary anesthetic. A comprehensive review of its
toxicology is beyond the scope of this report, since it can not be considered further as a halon replacement
candidate owing to its extremely potent anesthetic qualities.
A number of other brominated hydrocarbons have been evaluated as inhalation anesthetics over the years.
Most of these have been proven to have high anesthetic potency, which will preclude their consideration as halon
replacements. Also, given the regulatory prevention for production of HBFCs (see discussion of the Montreal
Protocol, Appendix B), the toxicological summary of these chemicals will be limited to a compilation of data from
the literature on the lethal, anesthetic, and cardiac sensitization potential of all HBFC compounds (Table 10).
38
-------
TABLE 10. TOXICITY SUMMARY OF HYDROBROMOCARBONS
Chemical
Lethal index
Anesthetic index
Cardiac sensitization
References
CF3CH2Br
Mice 10-min LC50 = 11.7%
N/A
Mice 10-min AD50 = 2.8%
Not anesthetic In 1 dog at concentration tested
(unspecified); respiratory depression, convulsions,
complete recovery
V. extrasystoie and tachycardia at anesthetic
concentrations
Arrhythmias at concentration tested
(unspecified)
1
CHf2CH2Br
Mice 10-min LC50 = 4.6%
Mice 10-min AD50 = 1.3%
Convulsions and rigidity in dogs
V. extrasystote and nodal arrhythmias at
anesthetic concentrations
22
CF3CHBrCH3
Mice 10-min LC50 = 7.6%
Mice 30-min LCsn = 7.2%
Mice 10-min AD50 = 1.7%
Mice 30-min ADso = 2.2%
Fal in blood pressure noted at anesthetic
concentrations
N/A
22
14
CF3CH2CH2Br
Mice 10-iTwri LC50 = 4.5%
Delayed death
Mice 10-min AD50 = 1.5%
N/A
22
CC1F2CH2Bt
Mice 10-min IC50 = 3.7%
Mice 10-min AD50»0.8%
A/v dissociation, v. tachycardia and fibrillation at
anesthetic concentrations
22
CF3CHBr2*
Mice 10-min IC50 ¦ 2%
Mice 30-min LCsn = 1.2%
Mice 10-mln AD50 = 0.4%
Mice 30-min ADsn * 0.5%
Fal in blood pressure rioted at anesthetic
concentrations
22
14
CI-foCF^CH^Br
Mice 10-min LCsn = 5.8%
Mice 10-min ADsn =1 25%
V. extrasystote at anesthetic concentrations
22
CF2CICHBrCH3
Mice 10-min LC50 = 2.2%
Mice 10-min AD50 = 0.56%
Tremors on recovery in dogs
A/v nodal irregularities at anesthetic
concentrations
22
CF^CHBrCH^Br
Mice 10-min LCsn = 0.67%
Mice 10-min ADqn = 0.1 %
N/A
22
CF3CBr(CHa)CH9Br
Anesthetic in rats at 2 ml
N/A
75
CF3CBrCICBrF2
Violent respiratory depression,
convulsions and death In rats
given 1 ml
Not anesthetic in rats given 1 ml
N/A
75
CF3CBrFCBrF2
Convulsions leading to death in
rats given 2 ml
N/A
N/A
75
CF3CHBrF
"teflurane"
No deaths in dogs given
10-50%
Anesthetic in 1 dog given
10-50%
Anesthetic in 30 humans at 25-50% with
supplemental O7
No EKG irregularities in dogs given 10%
No fibritations produced in dogs given 25% with
supplemental O? and 5-40 »o/kg epinephrine
76
77
(continued)
-------
TABLE 10. (concluded)
Chemical
Lethal index
Anesthetic index
Cardiac sensitization
References
CHBrF2
(Listed on Table 8)
No death in 1 dog given 50%
Anesthetic in 1 dog given 50% with supplemental
02
Unknown
76
CF3CF?CH?Br
Anesthetic within minutes in mice given 1-3%
Unknown
78
CFaCI-bCBrF?
Mice 30-min LCsn = 7.4%
Mice 30-min ADsn = 1 -9%
Unknown
14
CBrF2CHCIF
Death in 1 mouse at 5.8% For 4
minutes
Mice 30-roin LCso = 3.4%
Anesthetic in mice given 1.6-3.5% over 7-30
minutes
Mice 30-mln ADsn = 1.1%
Unknown
Unknown
78
14
CHF2CF2CH2Br
"halopropane"
Mice 30-min LC50 = 2.1 %
Mice 30-min AD50 = 0.53%
Anesthetic in humans given
1-2.5%
Unknown
Arrhythmias in humans given
1-2.5%
V. fibrillation in a( dogs under "light" (17/17)
and "deep" (5/5) anesthesia given 5-10 ng/kg
"Serious" Arrhythmias in 39% of humans given
0.4-3.9%
14
79
80
N/A
CBrF2CH2Br
Death in rats given 2-5% over
0.75-2 hrs
Loss of postural reflex at 0.25% over 18-hr
exposure in rats
N/A
81
CHBrCIF
Mice 30-min LCsn = 2.5%
Mice 30-min ADsn = 1.2%
N/A
14
CHF?CF?CHBrCI
Mice 30-min LCsn = 1 0%
Mice 30-min ADrd = 0.2%
N/A
14
CCIF?CH?Br
Mice 30-min LCsn = 3.7%
Mice 30-min ADvi = 0.8%
N/A
14
CBrF?CH?CI
Mice 30-min LCsn = 2.6%
Mice 30-min ADsn » 0.8%
N/A
14
CF?CICHBrF
Mice 30-min LCsn = 4.1 %
Mice 30-min ADso = 1.2%
N/A
14
CBrFpCHBrF
Mice 30-min LCsn = 1 6%
Mice 30-min ADsn = 0.7%
N/A
14
CCIF?CHBrCI
Mice 30-min ICsn * 1.4%
Mice 30-mln ADsn ¦ 0.5%
N/A
14
CBrFoCHF?
Mice 30-min LCsn = 16-7%
Mice 30-min ADso = 7.0%
N/A
14
N/A = not available
-------
From ihc data, it is apparent that all the HBFCs exhibit anesthetic and cardiac effects at some
concentration, most at concentrations below 3 percent. Dibrominatcd hydrocarbons arc generally the most toxic of
the HBFCs; therefore, it is unlikely that any of the CAAs identified as possible second-generation halon
replacement candidates will exhibit sufficiently low toxic properties to be considered further.
Several generalizations about the toxicity of HBFCs can be made:
(1) Fully halogenated compounds tend to be the least toxic, and halogenation increases the toxicity in the
order of F < CI < Br < I.
(2) A hydrogen atom bound to a carbon atom that is adjacent to a -CF3 group increases the toxicity;
therefore, geminal dibromocarbons (e.g., CF3CHBr2) are more toxic than vicinal dibromocarbons
(e.g., CF2BrCHFBr).
(3) Chemicals containing the group -CH2X, where X represents a halogen, are often mutagenic.
Fluoroiodocarbons-
Iodide is the heaviest halogen with an atomic weight of 126.9, In certain forms, it naturally occurs in
biological tissues. The thyroid is the organ engaged in the accumulation of iodine and the synthesis and storage of
iodotyrosines and iodothyroinines (82). In nonbiologica! molecules, iodine is usually considered an active leaving
group that is thought to confer toxicity. This is demonstrated by the high toxicity of iodomethane (CH3I) and
2-iodobutane (C4H9I), which are both extremely hazardous materials and human mutagens (11). In 1961,
Mathewson (83) stated that alkyl iodides were not useful as anesthetic agents because they did not possess narcotic
activity and were relatively nonvolatile. Krantz and colleagues (84) refuted this statement by demonstrating that a
number of iodinated compounds had anesthetic activity. Krantz showed that the addition of iodine to
"trifluoroethane" increased the parent molecule's anesthetic activity. However, the stepwise fluorination of the
terminal carbon atom, yielding mono-, di- and tri-fluoroethyl iodides, respectively, strengthens the caibon-iodinc
bond in proportion to the degree of fluorination. In other words, the adjacent carbon-fluorine bonds fix the iodine
more firmly to the molecule making the iodine a worse leaving group. Hine and Ghirardelli (85) demonstrated this
phenomenon by measuring the rate constant for the second order reactions between sodium phenoxidc and
iodoethane, l-fluoro-2-iodoethane, l,l-difluoro-2-iodoethane, and l,I,l-trifluoro-2-iodoethane. The rate constant
for the first reaction proved to be 17,450 times greater than that for the second reaction, i.e., the carbon-iodinc
bond was much stronger in l,l,l-trifluoro-2-iodoethane titan in iodoethane. This limited evidence suggests that
highly fluorinatcd iodocarbons may have the lowest toxicities of lite iodinated chemicals. At least for anesthesia,
perfluoroiodocarbons appear to be the least toxic iodine-containing halocarbons. This conclusion is based, in part,
on the fact that perfluorinatcd halocarbons do not have acidic hydrogen. However, for cardiac sensitization this
supposition may not be true. A summary of available toxicity information on fluoroiodocarbons is provided below.
41
-------
Early in this century, intravenous radiolabeled trifluoroiodomethane (CF3I131) was used to measure
cerebral blood flow in cats. The chemical appeared to have no observable toxic complications in the time period
studied (12-36 hours) (86). Lu et al. (75) investigated a number of mixed halocarbons as inhalation anesthetics
and showed that inhalation of 50 percent CF3I in a dog was not lethal or anesthetic, although the exposure
produced coughing, choking, retching and convulsions after 30 seconds. (NOTE: The effective fire
extinguishment concentration for CF3I is at approximately 3 percent)
Although not an original candidate listed on Table 8, a number of studies have been performed on
CF3CH2I (2,2,2-trifluoro-l-iodoelhane). CF3CH2I is a liquid at room temperature (BP = 55 °C). Robbins (22)
exposed mice for 10 minutes to CF3CH2I and derived the LC$o at 5 percent and the AD50 at 1.25 percent. For
comparison to a more well-known halon replacement candidate, Robbins derived values for HCFC-123
(CF3CHCI2) as 7.7 and 2.7 percent for the LC50 and AD50, respectively. Questions about the purity of chemicals
available for this study suggest these results should be viewed with some discretion.
Robbins also observed the anesthetic activity of CF3CH2I in three dogs. The chemical was anesthetic and
produced hypotension, variations in cardiac nodal rhythm, and ventricular extra systoles. Burns and colleagues
(87) tested the anesthetic activity of CF3CH2I in mice, exposing them by inhalation for 30 minutes to varying
concentrations. They found that anesthetic induction occurred within 1-2 minutes at concentration ranging from
5 to 7.3 percent and recovery was slow—between 5-12 minutes; however, all mice survived the exposure. Krantz
et al. (84) also studied CF3CH2I in detail as a potent anesthetic agent and found that it had an anesthetic potency
approximately the same as halothane (CF3CHBrCl). Krantz found that it produced no functional hepatic
impairment in dogs as shown by the sulfobromophthalein test. The blood pressure in dogs was not significantly
lowered with this agent. The electro-encephalograms for dogs and monkeys exhibited no unusual disturbances.
The dog's heart did not show any significant alterations during anesthesia; however, variations in cardiac nodal
rhythm and ventricular extrasystoles were observed in the monkey's heart. CF3CH2I did not appear to be
decomposed by body tissues. No increase in protein-bound iodine or iodide in scrum was seen after exposure. In
1961, Krantz administered CF3CH2I by inhalation to a healthy male volunteer. The subject experienced anesthesia
within 20 minutes using a dose of 11 ml. The induction was without incidence, and no changes were seen in the
electrocardiogram or blood pressure recordings. The recovery was rapid and uneventful, and the subject did not
experience any post-anesthetic sequelae. The chemical was used in a series of patients after this trial, but was later
abandoned owing to the frequent occurrence of cardiac arrhythmias. Consequently, CF3CH2I is not recommended
for consideration as a halon replacement.
Krantz and Rudo (88) investigated the anesthetic potency of CF3CF2I and found that 10 percent was
anesthetic in mice and rats but not dogs or monkeys, and the recovery from anesthesia in mice was uneventful.
Even 50 percent was not anesthetic in monkeys; however, it did provoke severe cardiac arrhythmias in monkeys
upon inhalation of the agent for 1 minute. They also studied CF3CHFI (BP = 39 °C) at 24 ntl/min and found that
42
-------
anesthesia, with good relaxation and no irritation, was produced in mice, but not monkeys. Prominent cardiac
arrhythmias were observed in monkeys. This research group also tested an iodinated ether, CH3OCF2CHFI
(BP = 118 °C). It caused anesthesia with good relaxation; however, it sensitized the heart to epinephrine causing
cardiac arrhythmias.
Di Paolo and Sandorfy (89) investigated the hydrogen bond-breaking ability of several chlorine-, bromine-
and iodine-containing fluorocarbons in an attempt to link this mechanism with anesthetic potency. Using infrared
spectroscopy, they measured the opening ofN-H N, OHO, and N-H 0=C types of hydrogen bonds in solution.
They found that perfluorinated molecules have no hydrogen bond-breaking potency. Fluorocarbons containing
only chlorine in addition to fluorine and carbon had only a weak hydrogen bond-breaking ability. Bromine- and
iodine-containing fluorocarbons were strong hydrogen bond breakers, and for nonhydrogen-containing halocarbons
the order of increasing hydrogen bond-breaking ability was Cl
secondary > primary. Thus. (CF3)jCI (tertiary) was more toxic than (CF3)2CFI (secondary), which in turn was
more toxic than CF3CF2CF2I (primary). This can be seen in results obtained from this laboratory on several
iodocarbons (Table 11). The authors staled that tertiary iodides react with nucleophiles under physiological
conditions, forming other, sometimes more toxic, products such as perfluoro-2-hydro-2-methyl-pcntane.
Several generalizations about the toxicity of fluoroiodocarbons can be made:
• For acute lethality of fluoroiodocarbons, the toxicity is lowest (highest LC50) for
1-iodoperfluorocarbons (primary).
• Fully halogcnatcd compounds have (he lowest toxicity. Hydrogen-containing iodocarbons tend to be
highly anesthetic.
HaIoethers~
Halogenated ethers have been investigated as anesthetic agents for as long as halocarbons have. Several
commonly used clinical anesthetics are halogenated ethers, e.g.. methoxyflurane (CHCI2CF2-O-CH3) and
fluroxene (CF3CH2-O-CH = CH2). Generally, halocthers arc potent at causing CNS effects, some even more
potent than halocarbons (89). Unsaturation increases the anesthetic potency as it does with hydrocarbons,
especially if halogenated. Clinical studies indicate that halocthers yield prolonged analgesia subsequent to
anesthesia, more so than halocarbons, and ethers evoke better muscular relaxation. Certain fluorinated ethers are
43
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TABLE 11. ACUTE LETHALITY OF FLUOROIODOCARBONS
Compound formula
1-hr mouse LC50 (ppm)
4-hr mouse LC50 (ppm)
C2F51
>10,000
82,000
(Listed on Table 8)
icf2cf2i
50-100
75
CF2CICCIFI
50-100
Unknown
CF3CFICF3
1,000-2,000
1,532 (900; LC^ in Wistar rat)
(Listed on Table 8)
CF3CFICF2CI
50-100
N/A
C4F9lt
>10,000
>20,000
C2F5CH2CH2!
100-500
219
C3FtCH2CH2I
250-500
N/A
C4F9CH2CH2I
1,000-5,000
2,003
n-CgF^I
>13,500
N/A
(Listed on Table 8)
(CF3)2CFCFICF3
250-500
N/A
(CF3)3CI
30-100
N/A
C2F5(CF3)2C-I
<50
N/A
C3F7(CF3bC-l
<50 (<25; LCW in Wistar rat)
N/A
•References 88 and 89; and Ulm, K., Hoechst AG Wiss. Labor, personal communication, 1992.
N/A = not available
marked CNS stimulants, such as Indoklon (CF3CH2-O-CH2CF3). which is used as a substitute for electroshock
therapy in treating mental illness. Halocthers reduce the metabolic rales in animals and humans less than
halocarbons. Haloethers generally produce less cardiac sensitization than halocarbons. Jn addition, evidence
indicates thai halocthers arc not as hepatotoxic as halocarbons. Table 12 summarizes the available toxicity
information on the lethal, anesthetic, and cardiac effects of halogenated ethers.
Few brominalcd fluorocthcrs have been studied. Van Poznak and Atrusio (92) investigated a nonflammable,
volatile liquid (BP = 88.8 °C) known as "roflurane" (CHj-O-CFjCHBrF), which produced excellent anesthesia in
animals and humans. The agent elicits more rapid anesthesia and recovery than nonbrominated mcthoxyflurane.
No significant alterations were noted in respiration in dogs undergoing anesthesia. Liver function tests and
biopsies did not reveal any evidence of abnormalities. Blood pressure did decline with increasing anesthesia
induction, but the decrease was less pronounced than with methoxyflurane. The electrocardiogram recordings
during roflurane anesthesia were normal and 10 n-g/kg of epinephrine did not produce cardiac arrhythmias. Liver,
lung, and kidneys biopsies were normal. No significant alterations were observed in plasma lipid concentrations in
dogs after 1 hour of roflurane anesthesia. Although this chemical looked promising as an inhalation anesthetic,
these authors did not publish more information and it was not used clinically thereafter.
44
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TABLE 12. TOXICITY SUMMARY OF HALOGENATED ETHERS
Chemical
Lethal index
Anesthetic index
Cardiac
sensitization
References
CF3CH2OCH2CH3
Mice 10-min
LC50 = 8%
Mice 10-min
AD50 = 4%
No cardiac
arrhythmias at
anesthetic
dose
22
CF3CH2OCH3
Mice 10-min
LC50 = 16%
N/A
Mice 10-min
AD50 = 8%
Anesthetic at 12 ml,
but not 10 ml, in
3 dogs; extremity
tremors, marked
salivation, mucous
membrane irritant
N/A
22
75
CHF2CH2OCH2CH3
Mice 10-min
LC50 = 9%
Mice 10-min
ADso = 4%
N/A
22
C2F5OC2F5
Not lethal in
1dog or 2 rats
given 75% in a
static chamber
No anesthesia in 1 dog
or 2 rats given 75% in
a static chamber
N/A
75
C2F5CH2OCH3
N/A
Anesthetic at 10 ml,
but not 6 ml, in 2 dogs;
muscular rigidity,
tremors, respiratory
depression, slow
recovery
Cardiac
irregularities in
dogs at 6 ml
75
C3F7CH2OCH3
Lethal in 1 rat
given 2 ml from
respiratory
arrest,
convulsions,
pulmonary
edema
Anesthetic in 1 rat at
2 ml; threatened
repiratory arrest, quick
recovery
N/A
75
CHF20CHF2
Not lethal to rats
Anesthetic in mice
N/A
93
(Listed in Table 8)
given 5% for
3 hr/day for
5 days
given above 20% for
2 hr
CF3OCF3
Not lethal in
N/A
N/A
93
(Listed in Table 8)
6 mice exposed
for 1 hrto 75%
CF3OCHF2
(Listed in Table 8)
Lethal due to
pulmonary
edema within
75 min to 24 hr
in mice exposed
to 50, 25, or
12.5% fori hr
N/A
N/A
93
(continued)
45
-------
TABLE 12. (continued)
Chemical
Lethal index
Anesthetic index
Cardiac
sensitization
References
CF3CH2OCHCH2
N/A
Anesthetic in 2 rats and
No cardiac
75
"Fluroxene"
6 dogs given 1 mi and
5.5 ml, respectively
sensitization at
anesthetic
concentration
N/A
Mice 10-min
AD50 = 4.7%
N/A
94
N/A
Paralyzant in dogs at
anesthetic dose
N/A
95
ch2=
Mice 1-hr
N/A
N/A
Ulm, K.,
CHCH2OCF2CF2H
LCso = > 1%
Rat 4-hr LC50 =
>0.13 < 0.67%
Personal
communi-
cation, 1992
C2F5CH2OCH=CH2
N/A
Not anesthetic in 2 rats
given 3 ml; pulmonary
edema, threatened
respiratory collapse,
peripheral vasodilation,
quick recovery
N/A
75
CH3OCF2CHBrCI
N/A
Anesthetic in 2 dogs
(concentration not
specified)
Atrioventricular
block and
arrhythmias in
conjunction
with
epinephrine
challenge
76
CH3OCF2CHCIF
N/A
Anesthetic in 2 dogs
(concentration not
specified)
Cardiac
arrhythmias in
conjunction
with
76
Lethal in mice at
Anesthetic in mice
epinephrine
challenge
N/A
96
3.1%
given 1.9 to 3.1%;
jerking and twitching
CH3OCF2CHCI2
"Methoxyflurane"
N/A
N/A
Anesthetic in 10 dogs
(concentration not
specified)
Anesthetic in
60 humans
Tachycardia
and cardiac
arrhytmias with
epinephrine
challenge
N/A
76
97
CHCIFOCH2F
Lethal in 1 dog
(concentration
not specified);
apnea, no pulse
or EKG
N/A
N/A
76
(continued)
46
-------
TABLE 12. (concluded)
Chemical
Lethal index
Anesthetic index
Cardiac
sensitization
References
ch2ciocf2chcif
N/A
Anesthetic in 1 dog
(concentration not
specified); twitching,
jerfcing, and shivering
Bradycardia
76
CF2CIOCF2CHCIF
(80%)
CCI2FOCF2CHF2
(20%)
N/A
Not anesthetic in 1 dog
(concentration not
specified); rigidity,
twitching, and shivering
N/A
70
CH2CIOCF2CF2H
Delayed death
24 to 48 hr after
anesthesia
Anesthetic in 2 dogs
(concentration not
specified)
Mild cardiac
sensitization
76
CH3OCF2CHFI
N/A
Anesthetic, good
relaxation
Cardiac
senstization at
anesthetic
doses
88
CF3CH2OCH2CF3
"Indoklon"
N/A
Convulsant in rats
given 30 ppm
N/A
88
CHCIFCF2OC3H7
N/A
Anesthetic in mice
given 1-1.3%
N/A
96
ch3
1
CHCIFCF2OCH
Lethal in mice at
2.4%
Anesthetic in mice
given 1.7-2.4%
N/A
96
CH;,
CHCIFCF2OC2H5
Delayed death
after anesthesia
Anesthetic in mice
given 1.9-3.1%
N/A
96
F5OCH2CH3Br
No effects in
4 mice for 30
min; saturated
vapor
N/A
N/A
87
CHF2CF2OCHFCHF2
All mice survived
exposures
between
2.3-10.2%
Anesthetic in mice
given 2.3-10.2%
N/A
87
CH3OCF2CHBrF
"Roflurane"
Good anesthetic
(concentration
not specified)
N/A
N/A
Excellent anesthetic in
animals and humans
N/A
No cardiac
sensitization in
conjunction
with 10 ii.g/kg
epinephrine in
dogs
98
92
N/A=not available.
47
-------
As with halocaibons, several generalizations can be made involving structure-activity observations:
(1) Halogcnalion increases anesthetic potency' in the order of F < CI < Br < I.
(2) Unsaturation increases potency.
(3) Methyl ethyl ethers are generally more potent than diethyl ethers.
(4) One or more hydrogen atoms on a molecule are generally required for CNS depression.
(5) Asymmetric (mixed), fully halogenated ethers (and halocarbons) generally tend to be convulsant.
(6) Compounds containing terminal asymmetric carbons (e.g., -CHFC1, -CHFBr, -CHClBr) tend to have
higher anesthetic potency.
(7) Higher boiling compounds lend to have longer recovery times from anesthesia.
(8) Ethers tend to have a smaller increment between the concentration producing CNS effects and the
concentration producing lethality.
Haloalkenes—
Haloalkenes is a term referring to the general class of chemicals composed of unsaturated, double bond
halogenated hydrocarbons. The incorporation of a double bond into fluorocarbons creates a unique chemical
environment. The strong electronegative force of halogen substituents generates a region of low electron density
between the adjacent carbon atoms, yielding a site susceptible to nucleophilic attack by bases or nucleophiles such
as fluoride, OH or NH2 (99). Saturated hydrocarbon bonds are not as susceptible to this nucleophilic attack.
Generally, a fluorine subslituent activates a double bond toward nucleophilic attack, and the order of reactivity is
related to the intermediate carbanior stability, i.e., tertiary is more reactive titan secondary which is more reactive
than primary (100). The order of nucleophilic susceptibility follows the observed trend in toxicity for this series of
perfluorinated alkenes:
(CF3)2C=CF2 > CF3CF=CF2 > CF2=CF2.
Krespan (101) demonstrated that the relationship of fluoride (F) to fluoroalkenc chemistry is similar to
that of protons (H') to hydroalkenes.
W + C'H2=CHCH2CH3-> CH3CHCH2CH3 -> CH3CH=CHCH3 + H* [7]
F + CF2=CFCF2CF3 ->• CF3CFCF2CF3 -> CF3CF=CFCF3 + F [8]
As seen in Reaction [8], the migration of the double bond is accomplished by the invasion of the
nucleophile F into the electron-deficient double bond with consequential leaving of F down the carbon chain.
This sequence is similar for hydroalkenes shown in Reaction [7] except the attack site is electron rich, and an
48
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clcctrophilic proton is the attacking en tit)'. Consequently, the toxicity of fluoroalkenes is thought to parallel the
susceptibility to nucleophilic attack.
The acute and chronic effects of haloalkenes must be taken into consideration when determining the
potential of the candidates as halon replacements. Haloalkenes can act as other halocarbons during short-term
exposures, but due to the highly metabolically active carbon-carbon double bond, long-term effects of exposure
become highly important. For example, in acute exposures, one must still be concerned with lethality and CNS
effects as well as cardiac sensitization. Pertaining to long-term effects, the bioactivalion mechanisms and the
reactivities of the metabolites formed from haloalkenes when activated by oxygen enzymes (oxidases, peroxidases,
and mixed-funclion oxygenases) must be considered. In haloalkenes, the formation of oxiranes (epoxides) will be
favored if (he halogen is located on an unsaturated carbon (as shown below). In haloalkanes, the electronegativity
of activated oxygen will induce the formation of alkanols and free radicals.
n v yO CI
\ /Cl \ / \ /
c = c —>- c c
/ \ / \ [9
Abreu (102) investigated the acute toxicity of a series of mono-brominated and -chlorinated clhenes,
propenes, and n-butenes and found that when the halogen was located on the unsaturated carbons, the anesthetic
potency was increased, but there was a decrease in the irritation, tissue damage, and overall toxicity. In addition,
haloalkenes with halogens located on the unsaturated carbons have less of a tendency to be metabolized in the
body. The anesthetic potency is evidently due to the molecules themselves as opposed to metabolic products.
Although none of the chemicals studied were fluorinated derivatives, halogen-substituted, unsaturated
hydrocarbons were more stable and less toxic than saturated analogues. One beneficial effect of halogen
substitution with chlorine, bromine, and iodine on the double bond may occur from stcric protection from
clcctrophilic attacks due to the bulk)' halogen atoms (103).
Halogenated ethenes were not considered as halon replacements in this survey of haloalkenes. Previous
work indicates that most, if not all, mono-chlorinated and -brominated ethenes are mutagenic and carcinogenic due
to metabolic activation. A summary of the work is provided supporting these conclusions. Vinyl chloride
(CH2=CHC1) lias been studied extensively and was found to be mutagenic and carcinogenic both in vitro and in
vivo (103). Vinyl bromide and vinyl fluoride have not been studied in detail; however, their metabolism is thought
to parallel that of vinyl chloride Accordingly, these compounds are suspected to metabolize into halooxiranes,
which would rearrange rapidly to form haloacetaldehyde. The oxiranes moieties alkylate DNA and proteins.
49
-------
Alkylation of DNA is one, and probably the most important, primary biochemical insult leading to mutations and
cancer (104).
Vinylidene halides (1,1-dihaloethylenes, CH2=CX2, where X is a halogen) are also fairly toxic
compounds. They are generally extremely hepatotoxic and mutagenic after metabolic activation (103). Variable
carcinogenic response have been reported with vinylidene halides, which is probably a result of interference of the
acute toxicity with the tumor promotion. On the other hand, 1,2-dihaloethylenes are not metabolized to mutagenic
products (103). The cis isomer is metabolized faster than the trans isomer, which is thought to be due to the steric
opening of the cis molecule.
Of the trihalo- and tetrahaloethylenes. the chlorinated compounds have been studied most extensively.
Again, information on mixed halogen compounds is limited, but generally trihaloethylenes are mutagenic. In
addition, these chemicals are often explosive in the vapor fortn such as trichloroethylene (11). Although also
mutagenic and carcinogenic, tctrachlorocthvlcnc is considered only moderately to slightly toxic (105).
Chlorotrifluoroethylene produces kidney dysfunction in rats after even a single 4-hour exposure to concentrations
up to 460 ppm. Bromotrifluoroethylene (CFBr=CF2) is a flammable gas and is considered poisonous (11). As a
result of these toxicity and flammability findings on halogenated ethenes, no chemical in this two-carbon
unsaturated class is recommended for further evaluation.
As seen from the information above, most of the data available on unsaturated chemicals are on
hydroalkenes. Little is known about mixed halogen fluoroalkenes. Some evidence from chlorinated and
fluorinated ethylenes indicates that fluorochloroethylenes are less toxic than only chlorine-substituted analogues.
This trend is seen in Table 13. Nonetheless, increasing the degree of fluorination at the site of unsaturation
increases the acute toxicity compared to alkenes containing hydrogen at the site of unsaturation. In other words,
more hydrogen atoms attached to the double-bond carbons confer a lower acute toxicity. This point becomes
important when determining which unsaturated chemicals listed on Table 8 will potentially have low toxicities.
Less information is available on haloalkenes with three or more carbons than for two-carbon haloalkenes.
Most of the information is on halocarbon moieties that are not also fluorinated. For example, Henschler (103) in
his review of metabolism of alkenes and alkynes suggests that allyl halides are subject to nucleophilic attack by
both the S\I and Sjs-2 mechanisms as shown below:
CH2=CH-CH2-X -> [CH2hiCHi=iCH2] + X" [101
Nu + CH2=CH-CH2-X -> [Nu-CH2-CH=CH21 + X- 111]
50
-------
TABLE 13. ACUTE INHALATION TOXICITY OF SEVERAL HALOGENATED ETHENES*
Chemical
Approximate lethal
LC50 (ppm)
Cardiac
concentration, ppm
sensitization
CH2=CH2
N/A
950,000 (mouse, exp. time
N/A
and 02 levels unspecified)
cci2=ch2
32,000
N/A
N/A
chci=cci2
8000
N/A
N/A
CCl2=CCI2
4000
N/A
N/A
CCl2=CF2
1000
N/A
N/A
CCIF=CF2
N/A
1000
4/4
CH^CHF
>800,000 (80% agent supple-
N/A
N/A
mented with 20% 02, 12.5 hr
CF;2=CH2
128,000
N/A
0/8
CF2=CF2
N/A
40,000
0/4
'Rat 4-hr exposure unless noted otherwise.
dumber of dogs experiencing cardiac sensitization (from Ref. 106 as in Ref. 88).
N/A = not available
or by radical mechanisms:
CH2=CH-CH2-X -> [CH2=CH- CII2 • Cll2-CII=CH2] + X* [12J
where x is a halogen and the radical is stabilized by resonance.
Alkenes that possess an allylic halogen are mutagenic with or without metabolic activation (107),
Therefore, chemicals that possess the following features are expected to be mutagenic:
C = C-C-X f 13]
This mutagenic feature holds tme regardless of whether the other substituents are hydrogen or methyl
(-CH3) groups. The mutagenic and carcinogenic potentials of allyl chloride and l-chloro-2-cyclohexene are well
known, C/.v-l,3-dichloropropcne is the most potent alkylating agent tested in the propene scries. The trans isomer
has reduced activity apparently due to stcric hinderance and neighboring effects favoring cation stabilization.
Good quantitative correlation exists between alkylating ability in vitro and direct mutagenic potencies in bacteria.
Alkylating ability is measured in the NBP-Test (4-(p-nitrobenzyl)-pyridine test) where the test agent and NBP are
reacted and the spectrophotometry extinctions are measured for the reaction mixture (108), Conversely, if the
halogen is located in positions other than the allylic position for propenes, the molecule is mutagenic only with
metabolic activation. Nonallylic halogens such as 1-chloro-l-propene (CICIHCHCH3) and 2-chloro-2-butene
(CH3CH=CC1CH3) lack direct genotoxic activity ; however, these become mutagenic with metabolic activation
(107). Finally, compounds with the halogen not located on position 1, 2, or 3, relative to the site of unsaturation
(e.g., CH2=CHCH2CH2C1) are not mutagenic with or without metabolic activation.
51
-------
From this information it becomes apparent that in order for an alkene not to possess mutagenic-hence
carcinogenic-potential, the leaving group, i.e., the halogen, must be located at least two carbons away from the site
of unsaturation. Unfortunately this trend has not been tested in fluorinated analogues. Nonetheless, Table 14
indicates which candidates from Table 8 will most likely be mutagenic or carcinogenic.
TABLE 14. PROPOSED MUTAGENICITY OF HALOALKENE CANDIDATES
Chemical
Mutagenic potential*
CH2=CHCF2Br
Mutagenic with or without activation
CH2=CHCFCBrF2
Not mutagenic
cf3
CH2=CHBrCF3
Mutagenic with activation only
CH2=CHCF2CBrF2
Not mutagenic
CH2=CBrCBrF2
Mutagenic with or without activation
CH2=CHCCiFCBrF2
Mutagenic with or without activation
BrCH=CBrCF3
Mutagenic with activation only
CF2=CHCBrf2
Mutagenic w/ith or without activation
BfCH=CHCFa
Mutagenic with activation only
"Predicted from trends based on work presented in References 1,103,107, and 108.
Consequently, only two of the haloalkene candidates hold the potential of not being mutagenic,
CH2=CHCF2CBrF2 and CH2=CHCFCBrF2
cf3
The other candidates will probably be mutagenic with or without metabolic activation.
Information of the toxicity of a handful of mixed haloalkenes has been reported. A fair amount of
research has been done to investigate the toxicity of one mixed halogen bulene, specifically 2,3-dichloro-
1,1,1,4,4,4- hexafluorobutene-2 (CF3CC1=CC1CF3, DCHFB). This chemical is an impurity of halothane in
concentrations ranging from 2 to 100 ppm (105). Concern about its toxic effects were expressed because halothane
has been used as a surgical anesthetic in humans. Several investigations of DCHFB have been performed
describing its toxicity. Cohen and associates (109) observed the acute toxicity of DCHFB in dogs and found
delayed anesthesia followed by convulsions and death in 1 hour. They also determined the LC50 for rhesus
monkeys to be 54 ppm for a 3-hour exposure where delayed death occurred 4 to 9 days after the exposure.
Chenoweth (110) showed that DCHFB was lethal in rats at 100 ppm for 4 hours. Some rats survived the exposure
for 1 or 2 hours. Lethal exposure was connected with signs of pulmonary irritation—pulmonary congestion and
52
-------
edema. Degenerative changes in the liver and kidney were also noted. Raventos and Lemon (111) studied the
toxicity of DCHFB in mice, rats, rabbits, monkeys, and dogs. A summaiy of their findings is presented in
Table 15 illustrating that the rat is the most sensitive species tested. They also found that the trans isomer was
about three times as toxic for mice as the cis isomer (1-hr LC50: trans, 61 ppm; 1-hr LCjq: cis, 179 ppm). These
researchers also studied other fluoroalkene impurities of halothane and determined the mouse 1-hour LC50 of trans
CF3CH=CBrCF3 to be 5000 ppm. Lung congestion and edema as well as other changes were the predominant
pathological findings; however, fatty liver changes were also present The chlorinated analog of this chemical,
trans CF3CH=CCICFi, was not found to be lethal for mice at 16,(KM) ppm. However, convulsions were observed at
concentrations higher than 5000 ppm. The approximate lethal concentration of a fluorinated analog,
CF3CH=CFCF3. was determined to be 200 ppm for a 4-hour exposure in rats (105). This chemical acts
predominately on the CNS and respiratory systems, and delayed death is the usual consequence. Long-term effects
of these chemicals were not reported.
TABLE 15. ACUTE INHALATION TOXICITY OF DCHFB IN VARIOUS SPECIES AT VARYING TIMES*
Species
LC50 ppm
1-hr exposure
2-hr exposure
3-hr exposure
4-hr exposure
6-hr exposure
Mice
55
39
N/A
26
20
Rats
47
28
N/A
16
N/A
Dogs
725
415
N/A
182
115
Monkeys
186
139
90
N/A
N/A
•Reference 105.
N/A = not available
Hocchst Chemical Company reported the acute toxicity of CH2=CHCF:CF2Br (99). They performed an
acute inhalation screening test wherein one mouse was exposed to 10,000 ppm for 1 hour. The mouse survived the
exposure and an observation period of several days. Clinical signs were reported as normal. As a result of these
findings, the researchers categorized the chemical as "weakly/practically not toxic."
Perfluoroisobutylene (PFIB) is by far the most acutely toxic fluoroalkene known. This is an important
fluoroalkene in combustion science because it is a possible thermal breakdown product of certain saturated and
unsaturated fluorocaibons. Table 16 reports the toxicity information of single exposures of rats to the chemical.
Animals generally succumb due to pulmonary edema with no discernible effects to other oTgan systems. This is a
similar case with a more well-known irritant and poison, phosgene (105). However, PFIB is approximately
10 times more toxic than phosgene. Some researchers find sublethal doses of PFIB cause pulmonary hemorrhages
and edema, degenerative changes in the kidney and. sometimes, in the liver. However, more often other organ
systems are not involved, and the acute toxic action is directly solely at the lung.
53
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TABLE 16. SUMMARY OF SINGLE EXPOSURE OF RATS TO PERFLUOROISOBUTYLENE *
Nominal
conc.
Exposure
time
Mortality
ratio
Clinical signs
Pathological changes
(ppm)
(hr)
1.0
4.25
2/2
Dyspnea, cyanosis, gasping,
convulsion
Acute pulmonary edema
0.5
6.0
2/2
Slight dyspnea after exposure,
delayed death within 24 hours
Acute pulmonary edema
0.3
6.0
2/0
None during exposure, slight
increase in respiratory rate,
weight loss next day, complete
recovery
None observed 9 days
after exposure
'Reference 105.
The anomalously high toxicity of PFJB has been suggested to be due to several causes. One theory
suggested is that PFIB toxicity stems from carbonyi fluoride (COF2) (99). However, the relative toxic
concentrations for the respective chemicals do not support this theory well. More likely, COF2 toxicity is related to
HF since the approximate lethal concentration of COF2 (4-hour exposure in rats) is 100 ppm, which would
correspond to 200 ppm of HF, a concentration well within the lethal range. PFIB is much more toxic than COF2,
and the clinical sequelae are different from either COF2 or HF. Another research group indicates that toxicity
increases with an increasing number of fluorine atoms (105), which was demonstrated by the series of fluorocthyie-
ncs reported in Table 13. However, this can not be the full explanation because hexafluoropropene (CF2=CFCF3)
is much less toxic with a 4-hour rat LC50 of 3000 ppm compared to a 4-hour rat approximate lethal concentration
of 0.76 ppm.
Several generalizations about the toxicity of fluoroalkenes become apparent:
(1) Halogenation around the site of unsaturation (C=C) increases the anesthetic potency, but decreases
the irritant potential, tissue damage, and overall toxicity.
(2) Mono-halogcnated ethenes are generally mutagenic and carcinogenic.
(3) 1,1-DihaIoethylenes (CH2=CX2, where X is a halogen) are generally mutagenic after metabolic
activation and hepatotoxic.
(4) 1,2-Dihaloethylenes (CHX=CHX, where X is a halogen) arc generally not mutagenic, and the cis
isomer is metabolized faster than the trans isomer.
(5) Trihaloelhylcnes and tetrahaloethylcnes arc generally mutagenic.
(6) The more hydrogens attached to the C=C bond, the lower the toxicity.
(7) Alkenes with allylic halogens (OC-C-X) arc generally mutagenic with or without metabolic
activation.
54
-------
(8) Halogenated alkenes are least toxic if the halogens are not bound to the double bond; consequently,
brominated alkenes require at least four carbons in order for the bromine to be located far enough
away from the unsaturated site.
Availability and Cost
To test chemicals in laboratory apparatuses for fire suppression and inertion capabilities, they must be
available in quantities of at least several hundred grams. Information on the cost and availability of the candidate
agents was gathered by performing Chcm Sources on-line computer searches and catalog and manufacturer
surveys. Once sources were identified, a personal contact was made within each company to verify the a%railability
of the chemicals indicated. Several key suppliers were identified, and these companies were provided a list of all
the proposed candidates to determine whether they would be able to custom-synthesize any of the other chemicals.
In addition, known fluorine chemists were surveyed to determine their abilities to custom-synthesize chemicals.
All the information gathered has been compiled and documented in Table 17.
A number of the proposed replacement candidates were found to be unavailable. For those chemicals that
were available, the major producers were Aldrich Chemical Company, PCR Incorporated, ICN Biomedicals, and
Crescent Chemical Company (Table 17). Where prices were quoted, they generally ranged between $100-$300 per
100 grains. A list of the suppliers' names, addresses, and telephone numbers is provided in Appendix C.
Present-day availability does not necessarily determine the availability of a chemical in the future
(6-10 years). Therefore, the availability criteria established herein were used primarily to determine whether a
proposed candidate could be tested in the near term. A firm commitment from a manufacturer would be required
in order for a chemical to be available in the quantities needed to satisfy market demands. Without this
commitment, the most attractive candidate agent would be useless unless it could be made available to the market
at a reasonable price.
Environmental Considerations
A review of the environmental regulations, both international and national, is presented in Appendix B.
A summary of recent amendments to the Montreal Protocol from the Meeting of the Parties in Copenhagen is also
provided in Appendix B as well as a discussion of the EPA's Significant New Alternatives Policy (SNAP) program.
All of the hydrobromofluorocaibons (HBFCs) (saturated) are to be regulated under the amendments to the
Montreal Protocol, None of the other chemicals in Table 8 is listed in US environmental regulations, with the
exception of several chemicals included in the Toxic Substances Control Act (TSCA) Inventory. Inclusion on the
TSCA Inventory, however, does not indicate whether a chemical is toxic, rather it indicates that a Premanufacture
Notice (PMN) has been submitted to the EPA. A summary of the chemicals' status on pertinent federal and
international regulations is provided in Table B-8.
55
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TABLE 17. PROPOSED CANDIDATE AVAILABILITY AND COST*
Name
CAS No.
Supplier
Cost
Deliver
HYDROBROMOFLUOROCARBONS
Dbromofluoromethane
1868-53-7
PCR
$25l25g
$95/100g
In stock
Crescent Chemical Company
$120/25g
$456/1OOg
3-4 wks
1,2-Dibromo-1,1,2-trfluoroethane
354-04-1
Crescent Chemcial Company
$106/1 Og
$326/100g
$710/250g
3-4 wks
PCR
$22/25g
S68/100g
$148/250g
In stock
2,2-Dibromo-1,1,1 -trifluoroethane
354-30-3
None
2,3-Dbromo-1,1,1-tnfluoropropane
431-21-0
Crescent Chemical Company
S216/25g
S648/100g
3-4 wks
PCR
S45/25g
S135/100g
In stock
Bromodiftuoromelhane
1511-62-2
Great lakes
$16/b
In stock
2-Bromo-1,1,1,2-tetrafluoroethane
124-72-1
None
F I.UOROIOOOCARBONS
Trifluoroiodomelhane (olher suppliers exist,
quantities and prices similar to those
indicated)
2314-97-8
Crescent Chemical Company
$274/25g
$802/100g
$2323/500g
3-4 wks
Aidrich Chemical Company
S94/25g
S276/100g
In stock
PCR
S65Q/kg in 5 kg
cpjanlites
In stock
Difluoroiodomethane
1493-03-4
None
Fluor oi odomethare
373-53-5
None
PentafluofCNodoethane
354-64-3
Crescent Chemical Company
S269/25g
S749/100g
$1123/250g
3-4 wks
PCR
S20/5g
S225/250g
4 wks
Aidrich Chemical Company
$70/25g
$459/300g
8 wks
Perfluofo-n-pfopyl iodde
754-34-7
PCR
$6Q/25g
$180/100g
In stock
Aldnch Chemical Company
$77/25q
N/A
Perfluofotsopccpyl iodide
677-690
Aidrich Chemical Company
$18/5g
$59/25g
In stock
PCR
542/25g
$166/100g
$615/500g
In stock
Crescent Chemical Company
$190/25 ml
3-4 wks
Perfluoro-ri-buty) iodide
423-39-2
PCR
$45/25g
$135/1 OOg
In stock
Crescent Chemical Company
$297/25 ml
3-4 wks
Akfrich Chemical Company
$25/25g
S72/100g
In stock
Perfluoro-n-hexyl iodide
355-43-1
Akiich Chemical Company
PCR
Crescent Chemical Company
S16/5g
S52/25g
S37/25g
$112/100g
$261/25 ml
In stock
In slock
N/A
* As of September 1993.
(continued)
56
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TABLE 17. (concluded)
Name
CAS No.
Supplier
Cost
Deliver
Perfluofo-n-octyl iodide
507-63-1
Aldrich Chemical Company
$25/5g
$83/25g
In slock
Crescent Chemical Company
$400/25 ml
3-4 wks
HAtOETHERS
PCR
$39/25g
S11S/100g
In stock
Perfluorodimethyl ether
1479-49-8
None
Methyl liiduoromethyl ether
421-14-7
James Adcock, Research
Chemist, University of Tennessee,
Knoxvie
N/A
N/A
FluraCorp
$18,860/ kg
N/A
Difluoromelhyl fluoromethyl ether
461-63-2
None
1.1,2.2-Tetrafluorodimethyl ether
1691-17-1
ICN Biomedicals
$488/1Og
3-4 wks
Tfifluoromelhyl dfluoromethyl ether
3822-68-2
Janes Adcock, Research
Chemist, University of Tennessee,
Knoxvie
m
N/A
Trifluoromethyl pentafluoroelhyl ether
2356-61-8
James Adcock, Research
Chemist, University of Tennessee,
Knoxville
N/A
N/A
Peril uorooxetane
425-82-1
James Adcock, Research
Chemist, University of Tennessee,
Knoxville
N/A
N/A
1,1,2,2-Telrafluoroethyl difluoromethyl ether
32778-11-3
PCR
$2667/kg
N/A
Flura Corp
$5875/kg
N/A
1,1,1-T tifluoroisopropyl triftuoromethyl ether
32793-58-1
None
1,1,1-T rifluoroethyl difluoromelhyl ether
1885-48-9
None
1,1-Muoroethyl fluoromethyl ether
None
None
Perfluorodimethoxymelhane
53772-78-4
James Adcock, Research
Chemist, University of Tennessee,
Knoxville
N/A
N/A
Diflooromethyl bromodifluoromethyl ether
None
None
T rifluoromethyl bromodifluoromelliyl ether
None
None
Dtlluoromethyl brormotetrafluoroethyt ether
32778-13-5
None
Methyl bromodilluoromethyl ether
None
None
BROMOFLUORQALKENES
1 -Bromo-1,1 -difluoropropene
420-906
PCR
$185Q/50g
$6000/250g
4 mo
3-(Bromodifluoromethyl)-3,4,4,4-tetrafluoro-1-bulene
254664-5
None
2-Bromo-3,3,3-trifluoro-1 -propene
1514-82-5
Japon Halon
$1900/kg
In-stock
4-Bro!iio-3,3,4,4-tetrafluoro-1-butene
18599-22-9
Fluorochern Limited
$1175/100g
10-14 days
2,3-Dtorom o-3,3-defluoro-1 -propene
677-35-0
PCR
$1300/50g
$4500/250g
2 mo
4-Brorno-3-chloro-3,4,4-trifluoro-1-bulene
37425-4
PCR
$25/25g
S85/100g
4 wks
Crescent Chemical Company
S12025g
S408/100g
3-4 wks
N/A
1,2-Dbromo-3,3,3-trifluofo-1 -propene
431-22-1
PCR
$700/50g
$200W250g
3mo
3-Bromo-1,1,3,3-tetrafluoro-1 propene
460-61-7
None
1 -Bromo-3,3,3-trifluoro-1 -propene
460-33-3
Bdl Bannister, Research Chemist,
University of Massachusetts,
Lowell
N/A
N/A
N/A~Not available.
57
-------
SECTION 4
RECOMMENDED AGENTS
PHYSICAL ACTION AGENTS
Taking into consideration information about physical properties, toxicity, availability and cost, fire
suppression capabilities, environmental considerations, and regulatory concerns, the chemicals listed in Table 2
were prioritized and recommendations made for future testing of certain chemicals. The chemicals were grouped
according to specifications outlined in Section 1 of this report. Table 18 shows the group designation of the
physical action agents considered during the course of the candidate survey
The following Group 1 chemicals warrant testing in the laboratory: FC-14. HCFC-22, HFC-23, FC-116,
HCFC-124, HFC-125, HFC-134a, FC-218, FC-C318, and FC-3-1-10. All of these chemicals have attractive
physical properties, potentially low toxicities (although in some cases toxicity data are limited), acceptable
environmental characteristics, and are available for testing. Of these chemicals, all have been tested in the cup
burner, and extinguishment concentrations ranged between 6 and 12 percent. All will need to be tested for
explosion inertion in the hemispherical bomb. Also. HFCs 32, 143a, and 152a, and HCFCH2b arc available and
have low toxicities, but they are flammable and could only be used as minor components in blends, not as neat
agents. A summary of known toxicity information of the physical action agents is presented in Section 2.
Group 2 chemicals also recommended for laboratory-scale testing include HFCs 134, 227ea, 236fa, and
245cb and HCFC-124a. Toxicity information is very limited for these chemicals, however, and extensive
toxicological testing would be needed. These chemicals have attractive physical properties and predicted flame
extinguishment concentrations ranging between 8 and 11 percent. HFC 134 has been tested in the cup burner and
has a measured extinguishment concentration of 11 percent. HFCs 227ea, 236fa, and 245cb are particularly
attractive candidates because of the CF3 groups enhancing extinguishment capabilities. These chemicals are
commercially available and therefore can be tested.
Group 3 chemicals are generally not available; however, several from this group look attractive. For
example, HFC 227ca appears to have a relatively low toxicity based on limited acute data, its boiling and freezing
points are known, and it has a CF3 group that would presumably enhance its extinguishment capabilities. HFC
236cb, HCFCs 244db, 244bb, and 245eb also have attractive structural features as fire cxtinguishants because of
their CF3 groups. Only HFC 236cb and HCFC 244bb have limited acute toxicity information in mice. No toxicity
information is available for the others.
58
-------
TABLE 18. CANDIDATE GROUP LIST OF PHYSICAL ACTION AGENTS
Group
Halocarbon no.
Formula
Comment
1
14
cf4
Toxicity expected to be low
Recommended
22
chcif2
Low toxicity
for
23
chf3
Long atmospheric lifetime
Lab-testing
32
CH2F2
Flammable
116
CF3CF3
Low toxicity
124
chcifcf3
Low toxicity
125
chf2cf3
Limited availability
134a
ch2fcf3
Low toxicity
142b
ccif2ch3
Flammable
143a
CH3CF3
Flammable
152a
chf2ch3
Very low toxicity
218
Op 3OP jCF ^
Low toxicity
3-1-10
C4P10
Toxicity expected to be low
C318
C4f=8
Decomposition products may be toxic
2
124a
chf2ccif2
Unknown tox but expected to be low
Recommended
134
chf2chf2
Unknown tox but expected to be low
for
227ea
CF3CHFCF3
Unknown tox but expected to be low
Lab-testing
236fa
cf3ch2cf3
Acute toxicity known
245cb
cf3cf2ch3
Unknown tox but expected to be low
3
142a
chcifch2f
No data
Unavailable
C216
cf2cf2cf2
No data
Commercially
226ba
cf3ccifchf2
No data
227ca
cf3cf2cf2h
Acute toxicity known
C234
cf2cf2ch2
No data
235cc
ch2fcf2ccif2
Acute toxicity known
235da
cf3chcichf2
Anesthetic at low concentrations
235ca
chf2cf2chcif
Anesthetic at low concentrations
236cb
ch2fcf2cf3
No data
244db
cf3chcich2f
No data
244bb
cf3ccifch3
Anesthetic at low concentrations
244ca
chf2cf2ch2ci
No data
244fb
ccif2ch2chf2
Acute toxicity known
244cb
ch2fcf2chcif
No data
244da
chf2chcichf2
Anesthetic at low concentrations
245eb
cf3chfch2f
No data
245ea
chf2chfchf2
No data
245ca
chf2chf2ch2f
No data
254eb
CF3CHFCH3
Probably flammable, no data
254ea
chf2chfch2f
Probably flammable, no data
254fa
chf2ch2chf2
Probably flammable, no data
254ca
ch2cf2ch2f
Probably flammable, no data
254cb
chf2cf2ch3
Probably flammable, no data
4
31
ch2cif
Cancer-causing in lab animals
Unacceptable
59
-------
One chemical rejected from the Table 2 list was HCFC 31 since it has been shown to produce cancer in
animals. This chemical is considered a Group 4 chemical and will not be considered further.
CHEMICAL ACTION AGENTS
Several classes of chemicals exhibit superior fire suppression and inertion effectiveness. The
dibromofluorocarbons are extremely effective. However, owing to the imposed regulations of the Copenhagen
amendments to the Montreal Protocol, production of the HBFCs listed as candidates will be prohibited. Therefore,
it is not recommended that any HBFCs be investigated further.
Although several fluoroiodocarbons were identified that exhibit superior (lame suppression capabilities,
the higher molecular weight compounds did not show as much promise when tested for their inertion capabilities.
This may have been due to the small quantity of test material limiting the number of experimental tests that could
be performed. Accordingly, the inerting concentration (IC) was determined to be within a specified range. More
thorough testing would define the IC more precisely. Nonetheless, it appears that the toxicity of the
pcrfluoroiodocarbons may be sufficiently low to allow ihe use of these chemicals as total-flood agents. For those
chemicals with boiling points above 20-30 "C nominally, an alternate means of dispersal would most likely be
required. Misting technology could be investigated for this purpose.
A number of halogenated ethers have been investigated as possible halon replacement agents. These
include both brominatcd and nonbrominated compounds. The nonbrominated fluoroethers perform as physical
action agents similar to HFCs. Bromofluoroethcrs are expected to perform similarly to HBFCs. Although none of
the candidates was tested in the NMERI laboratory, results from other researchers indicate that the flame
suppression capabilities are similar to halocarbon analogues. In addition, uncertainly still remains as to whether
the addition of the oxygen atom will reduce the atmospheric lifetime enough to limit the ODP to acceptable levels.
Finally, little toxicological information exists on the haloether candidates presented in Table 8. Consequently, a
high priority is not recommended for the haloethers.
A survey of the toxicological aspects of bromofluoroalkenes reveals that few of these chemicals have
sufficiently low toxicities to allow their use as halon replacement agents. Many of the two- and three-carbon
candidates are most likely carcinogenic. Only haloalkenes with four or more carbons will possibly be
nonmutagenic and noncarcinogenic. Therefore, only two chemicals from Table 8 would be considered viable
candidates. Unfortunately, the molecular weights of the four- or more carbon haloalkenes are relatively high
compared to Halon 1301, which will reduce the apparent effectiveness if expressed on a weight equivalency basis.
In addition, these two candidates have high boiling points, which means they will require misting for dispersion.
60
-------
In light of these conclusions, it is recommended that the perfluoroiodocarbons and the two
bromofluoroalkenes listed in Group 1 (Table 19) be investigated further. Acute toxicity measures will be required
on these candidates in relation to the flame suppression and inertion concentrations. In addition, aspects of the
candidates' shelf-life, manuiacturability, and materials compatibility should be investigated. Finally, candidate
surveys should be performed on other classes of chemicals to investigate possible second-generation replacements
for halons.
61
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TABLE 19. CANDIDATE CROUP LIST OF CHEMICAL ACTION AGENTS
Group
Name
Formula
Comment
1
T rifluoroiodomethane
cf3i
Toxic?
Recommended
Pentafl uoroiodoethane
CF3CF2I
Toxic?
for
Perfluoro-n-propyl iodide
CF3CF2CF2I
Toxic?
Lab-Testing
Perfluoro-n-butyl iodide
CF3CF2CF2CF2I
Toxic?
Perfluoron-hexyl iodide
CF3(CF2)4CF2l
Toxic?
4-Bromo-3,3,4,4-tetrafluono-1-butene
CH2=CHCF2CBrfr2
Toxic?
2
Perfluoro-n-octyl iodide
CF3(CF2)6CF2l
BP high
Recommended
1,1,2,2-Tetrafluonxf methyl ether
CHF2OCHF2
Need data
for
1,1,2,2-T etrafluoroethyl difluoromethyl ether
CHF2OCF2CHF2
Need data
Lab-Testing
1,1,1-Trifluoroethyl difluoromethyl ether
CF3CH2OCHF2
Need data
3
Difluoroiodomethane
CHF2I
No data
Unavailable
Fluoroiodomethane
CH2FI
Carcinogenic?
Commercially
Perfluofodimethyl ether
CF3OCF3
Long life?
Methyl trifluoromethyl ether
CH3OCF3
Expensive; flammable
Difluoromethyl fluoromethyl ether
CHF2OCH2F
No data
Trifluoromethyl difluoromethyl ether
CF3OCHF2
No data
Trifluoromethyl pentafluoroethyl ether
CF3OCF2CHF2
Not available
Peril uorooxatane
-CF2CF2CF2O-
Long life
1,1,1 triftuoroisopropyl trifluoromethyl ether
CF3(CH3)CHOCF3
Not available
Perfluorocimethoxymethane
CF3OCF2OCF3
No data
Difluoromethyl bromodifluoromethyl ether
CHF20CBrF2
No data
Trifluoromethyl bromodfluoromethyl ether
CF3OCBrF2
No data
Difluoromethyl bromotetrafluoroethyl ether
CHF20CF2CBrF2
Need data
Methyl bromodifluoromethyl ether
CH3OCBrF2
No data
3- Bromo-3,3-difl itoroprope ne
CH2=CHCBrF2
Mutagenic
S-fBromodifluoromethylJ-S^.A^tetrafluoro-l-butene
CH2=CHC(CBrF2)FCF3
Not available
1 -Bromo-3,3,3-trifluoro-1 -propene
Br€H=CHCF3
Mutagenic?
2,3-Dibromo-3,3-difUjoro-1-propene
CH2=CBrCBrF2
Mutagenic
4-Bromo-3-chloro-3,4,4-trifluoro-1-butsne
CH2=CHCCIFCBrF2
Mutagenic
3-Bromo-1,1,3,3-tetrafluoro-1 -propene
CF2=CHCBrF2
Highly toxic?
1,2-Dibromo-3,3,3-trifluoro-l-propene
BfCH=CBrCF3
Mutagenic?
4
Perfluoroisopropyl iodide
CF3CFICF3
Too toxic
Unacceptable
1,1 -Difluoroethyl fluoromethyl ether
CHF2CH20CH2F
Flammable? Available?
Dibromofluoro me thane
CHBr2F
High ODP
1,2-Dibromo-1,1,2-trfluoroethane
CBrF2CHBiF
Highly toxic, High OOP
2,2-Dibromo-1,1,1-trifluoroethane
CHBr2CF3
Highly toxic. High OOP
2,3-Dibromo-1,1,1-trifluoropropane
CF3CHBrCH2Br
Highly toxic, High OOP
Bromodifluoromethane
CHBrF2
High ODP
2- Bromo-1,1,1,2-tetrafl uoroethane
CF3CHBrF
High ODP
62
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REFERENCES
1. Skaggs, S. R., Hcinoncn, E. W., Moore, T.A., and Kirst, J. A., Low Ozone-Depleting Halocarbons as Total-
Flood Agents: Volume 2--Laboratory-Scale Fire Suppression and Explosion Prevention Testing, EPA-
600/R-95-150b, National Risk Management Research Laboratory, Research Triangle Park, NC.
September 1995.
2. Barat, R. B., Sarofim, A. F., Longwell, J. P., and Bozzelli, J. W., "Inhibition of a Fuel Lean Ethylene/Air
Flame in a Jet Stirred Combustor by Methyl Chloride: Experimental and Mechanistic Analysis,"
Combustion Science and Technology, 74:361-.178, 1990.
3. Tapscott, R. E., Moore, T. A., and Moore, J. P., A Database ofllalocarbon Candidates for Ilalon and
CFC Alternatives, International Conference on CFC and Halon Alternatives, Washington, DC, 10-11
October 1989.
4. Nimif., J S.. Skaggs, S. R, and Floden, J. R.. Estimation Techniques for Properties of CFC and Halon
Alternatives, International Conference on CFC and Halon Alterantives. Baltimore, MD, 27-29 November
1990.
5. "Seven CFC Producers Announce Third Program to Test Alternatives," Journal of the Air Pollution
Control Association, Vol. 39, pp. 1125-1128, 1989.
6. Clark, D. G., and Reinhardt, C. F., The Toxicology of the Halogenated Fire Extinguishing Agents,
General Chemicals Group, Runcorn, England, undated.
7. Aviado, D. M., and Drimal, J., "Five Fluorocaibons for Administration of Aerosol Bronchodilators,"
Journal of Clinical Pharmacology, Vol. 15, pp. 116-128, 1975.
8. Fishbein, L., "Industrial Mutagens and Potential Mutagens, I. Halogenated Aliphatic Derivatives,"
Mutation Research, Vol. 32, pp. 267-308, 1976.
9. Schieble, T. M., Coasta, A. K., Heffel, D. F., and Trudell, J. R., "Comparative Toxicity of Halothane.
Isoflurane, Hypoxia, and Phcnobarbital Induction in Monolayer Cultures of Rat Hepatocytes,"
Anesthesiology, Vol. 68. pp. 485-494, 1988.
10. Kipko. W. L„ "Beyond CFCs: Extending the Search for New Refrigerants," Revue Internationale du
Froid, Vol. 13, pp. 79-85, 1990.
11. Sax, N. I., and Lewis, R. J., Dangerous Properties of Industrial Materials, Volumes I-III (seventh
edition), von Noslrand Reinhold, New York, 1989.
12. Regan, B. M., "Method of Inducing Anesthesia with 2-Halo-l,l,2,2-tetrafluoropropanes," U.S. Patent No.
3,362,874, 1966.
13. Graham, R. C., Toxicity Review, Fluorocarbon 152a, E. I. Du Pont de Nemours and Company, Haskell
Laboratory for Toxicity and Industrial Medicine, Wilmington, DE, 1 June 1987.
63
-------
14. Davics, R. H., Bagnell, R. D., Bell, W., and Jones, W, G. M., "The Hydrogen Bond Proton Donor
Properties of Volatile Halogenated Hydrocarbons and Ethers and Their Mode of Action in Anesthesia,"
International Journal of Quantum Chemistry: Quantum Biology Symposium, No. 3, pp. 171-185, 1976.
15. U. S. Environmental Protection Agency, Hydrojluorocarbons and Hydrochlorofluorocarbons: Interim
Report, Office of Toxic Substances, Washington, DC, 1990,
16. LongstafT, E., Robinson, M., Bradbrook, C., Styles, J. A., and Purchase, I. F. H., "Genotoxicity and
Carcinogenicity of Fluorocarbons; Assessment by Short-term In Vitro Tests and Chronic Exposure in
Rats," Toxicology and Applied Pharmacology, Vol, 72, p. 15, 1984.
17. Graham, R. C., Toxicity Reviews -HFC-23, HFC-32, FC-116, FC-218, and IICFC 31, E. I. Du Pont de
Nemours and Company. Haskell Laboratory for Toxicity and Industrial Medicine. Wilmington, DE,
1982-1986.
18. Litchfield, M. H,, and LongstafT, E., "The Toxicological Evaluation of Chlorofluorocarbon 22 (CFC 22),"
Chemical Toxicology, Vol. 22, pp. 465-475, 1984,
19. Clayton, J. W., Jr., "Fluorocarbon Toxicity and Biological Action," Fluorine Chemistry Reviews, Vol. 1,
p. 197, 1967.
20. Clayton, J. W,, Jr.. "The Toxicity of Fluorocarbons with Special Reference to Chemical Constitution,"
Journal of Occupational Medicine, Vol. 4, p. 263, 1962.
21. Rusch, G. M., Symposium Program for Alternative Fluorocarbon Toxicology Testing Activities: Current
Results, Meeting of the American College of Toxicology, October 1989.
22. Robbins, B. H., "Preliminary Studies of the Anesthetic Activity of Fluorinated Hydrocarbons," Journal of
Pharmacology and Experimental Therapeutics, Vol. 86, p. 197-204, 1946.
23 Burns, T. H. S., Hall, J. M., Brachen, A., and Gouldstone, G., "Fluorine Compounds in Anaesthesia,"
Anaesthesia, Vol. 37, p. 278, 1982,
24. Regan, B. M., "Method of Inducing Anesthesia with 2-Halo-l,l,l,3,3-pentafluoropropanes," U.S. Patent
No. 3,499,089; 1967.
25. E. I. Du Pont de Nemours and Company, Haskell Laboratory for Toxicity and Industrial Medicine,
Wilmington, DE, Toxicity Summary, FC-32, Report, 1988.
26. Programme for Alternative Fluorocarbon Toxicity Testing, HFC-32, Washington, DC, September 1992.
27. Graham, R. C., Toxicity Review, FC-116, E. I. DuPont de Nemours and Company, Haskell Laboratory for
Toxicity and Industrial Medicine, Wilmington, DE, 1986.
28. E. I. Du Pont de Nemours and Company, Haskell Laboratory for Toxicology and Industrial Medicine,
Wilmington. DE, Toxicity Summary, FC-142b, Report, 1987.
29. Seckar, J. A,, Trochimowicz, H, J., and Hogan, G. K., "Toxicological Evaluation of Hydrochlorofluoro-
carbon 142b "Journal of Chemical Toxicology, Vol, 24, pp. 237-240, 1986.
64
-------
30. E. I, Du Pont de Nemours and Company, Haskell Laboratory for Toxicology and Industrial Medicine,
Wilmington, DE, Toxicity Summary, FC-I43a, Report, 1988.
31. Aviado, D. M., "Toxicity of Propellants," Fortschritte Der Arzheimittelforschung, Vol. 18, pp. 365-397,
1974.
32. Aviado, D. M., and Smith, D.G., "Toxicity of Aerosol Propellants in the Respiratory and Circulatory
Systems, Part I. Cardiac Arrhythmias in the Mouse," Toxicology, Vol. 2, pp. 31-42, 1974.
33. Belej, M. A., and Aviado, D. M., "Cardiopulmonary Toxicity of Propellants for Aerosols," Journal of
Clinical Pharmacology, Vol. 50, pp. 105-115, 1975.
34. Aviado, D, M., and Belej, M. A., "Toxicity of Aerosol Propellants in the Respiratory and Circulatory
Systems, Part V. Ventricular Function in the Dog," Toxicology, Vol. 3, pp. 79-86, 1975.
35. Fishbein, L., "Industrial Mutagens and Potential Mutagens, I. Halogenated Aliphatic Derivatives,"
Mutation Research, Vol. 32, pp. 267-308, 1976.
36. E. 1. Du Pont de Nemours and Company, Haskell Laboratory of Toxicology and Industrial Medicine,
Wilmington, DE, Toxicity Summary, Freon 218, January 1986.
37. Aviado, D. M., and Smith, D. G., Toxicity of Aerosol Propellants in the Respiratory and Circulation
Systems. Part VIII. Respiration and Circulation ofPrimates," Toxicology, Vol. 3, pp. 241-252, 1975.
38. Clayton, J. W., Jr.. "Fluorocarbon Toxicity and Biological Action." In Toxicity of Anesthetics, Fink, B.
R.. cd.. Williams and Wilkins, Baltimore, MD, 1968.
39. Danishevskiy, S. L., and Kochanov, M. M., "Toxicity of Some Fluoro-Organic Compounds," translated by
the Foreign Technology Division, Wright-Patterson Air Force Base, Dayton, OH, Document No. FTD-
ID(RS)T-0112-89, pp. 3-8, 1961.
40. Bjornson, G., and Fox, II. M., "Pyrolysis of Octafluorocyclobutane," U.S. Patent No. 3652691, March
1972.
41. Chemical Marketing Reporter, p. 50, March 13, 1989.
42. Has/.cldinc, R. N,, and Sharpe, A. G., Fluorine and its Compounds, John Wiley and Sons, Inc., New
York, 1951.
43. Simons, J. H., ed., Fluorine Chemistry, Vol. I, Academic Press, New York, 1950.
44 Sheppard, W. A., and Sharts, C. M., Organic Fluorine Chemistry, W. A. Benjamin, Inc., New York,
1969.
45. Simons, J. H., ed., Fluorine Chemistry, Vol. V, Academic Press, New York, 1964.
46. Banks, R. E., and Barlow, M. G., cds., Fluorocarbon and Related Chemistry, Vol. 3, Burlington House,
London, 1976.
65
-------
47.
Banks, R. E, Fluorocarbons and Their Derivatives, MacDonald Technical and Scientific, London, 1970.
48. Chambers, R. D., fluorine in Organic Chemistry, John Wiley and Sons, Inc., New York, 1973.
49. Lovelace, A. M., Rausch, D. A., and Postelnek. W., Aliphatic Fluorine Compounds, Reinhold Publishing
Corporation, New York, 1958.
50. Banks, R. E., and Barlow, M. G., cds., Fluorocarbon and Related Chemistry, Vol. 1, Burlington House,
London, 1971.
51. Banks, R. E., and Barlow, M. G., cds., Fluorocarbon and Related Chemistry, Vol. 2, Burlington House,
London, 1974.
52. Banks, R. E., ed., Organofluorine Chemicals and Their Industrial Applications, Ellis Horwood, Ltd.,
Chichester, England, 1979.
53. Banks, R. E., Preparation, Properties, and Industrial Applications of Organofluorine Compounds, Jolin
Wiley and Sons, Inc., New York, 1982.
54. Simons, J. H., Fluorine Chemistry, Vol. II, Academic Press, New York, 1954.
55. Mettille. F, J., and Burton, D. J.. "Methods for the Introduction of Hydrogen into Fiuorinated
Compounds," Fluorine Chemistry Reviews, Vol. 1, pp. 315-358, 1967.
56. Wcast, R. C., ed., The CRC Handbook of Chemistry and Physics, 69th Edition, Clicmical Rubber
Company, Boca Raton, FL, 1989.
57. Gann, R, G., Barnes, 1. D., Davis, S., Harris, J. S., Harris, R. H., Jr., Herron, J, T., Levin, B. C., Mopsik,
F. I., Notarianni, K. A., Nyden, M. R„ Paabo, M„ and Richer, R. E„ Preliminary Screening Procedures
and Criteria for Replacements for Halons 12! / and 1301, Final Report, Center for Fire Research,
National institute of Standards and Technology, Gaithersburg, MD, June 1990.
58. Hirst, R_, and Booth, K., "Measurement of Flame-Extinguishing Concentrations," Fire Technology.
Vol. 13, pp. 296-315, 1977.
59. Sheinson, R. S., Penner-IIahn, J. E., and Indritz, D., "The Physical and Chemical Action of Fire
Suppressants," Fire Safety Journal. Vol. 15, pp. 437-450, 1990.
60. Finnerty, A. E., The Physical and Chemical Mechanisms Behind Fire-Safe Fuels, BRL Report No. 1947,
U.S. Army Ballistic Research Laboratories, Aberdeen Proving Ground, MD, November 1976.
61. Tapscott, R. E., Moore, T. A,, Moore, J. P., Rodriguez, M. L., Morehouse, E. T., Jr., and Walker, J. L.,
Next Generation Fire Extinguishing Agent, Phase V — Initiation of Halon Replacement Development,
ESL-TR-87-03, Vol. 5 of 5, Engineering and Serv ices Laboratory , Tyndall Air Force Base, FL, August
1989.
62. Brown, A. C., Canosa-Mas, C. E.( Parr, A. D., Rothwell, K., and Wayne, R. P., "Tropospheric Lifetimes
of Three Compounds for Possible Replacement of CFCs and Halons," Nature, Vol. 347, pp. 541-543,
October 11, 1990.
66
-------
63. Nimitz, J. S., Tapscott, R. E., Skaggs, S R, and Beeson, H. D., Alternative Training Agents. Phase I —
Survey of Near Term Candidate Fire Extinguishing Agents and Predicting Properties of Halocarhon
Mixtures, ESL-TR-90-39, Vol. 1 of 4, Tyndall Air Force Base, FL, April 1990.
64. Singh, O. N., Borchers, R., Fabian, P., Lai, S., and Subbaraya, B. H., "Measurements of Atmospheric
BrOx Radicals in the Tropical and Mid-Latitude Atmosphere," Nature, Vol. 334, pp. 593-595, 1988.
65. Naj, A. K., "Bromines May be Harming Ozone Layer as Much as Fluorocarbons, Report Says," Wall
Street Journal, 30 August 1988.
66. Rice, C., "Thomas Calls for CFC and Halon Phaseout," Environmental News, EPA Press Release,
September 26, 1988,
67. Atmospheric Ozone. Vols. I, II, and III. U.S. National Aeronautics and Space Administration,
Washington, DC, 1985.
68. Hileman, B. H., "Global Warming," Chemical and Engineering News, pp. 25-44, March 3, 1989.
69. Emblcr, L. R., Layman, P. L., Lcpkowski, W., and Zurer, P. S., "The Changing Atmosphere," Chemical
and Engineering News, Vol. 64, pp. 14-64, 1986.
70. Hoffman, J. S., Assessing the Risks of Trace Gases That Can Modify the Stratosphere, Vol. 3, Chapters 6-
18, EPA-400/1 -87-001 c (NTIS PB88-191861), U.S. Environmental Protection Agency, Washington, DC,
December 1987.
71. Ramanathan, V., Cicerone, R. J., Singh, H. B., and Kiehl, J. T., "Trace Gas Trends and Their Potential
Role in Climate Change," Journal of Geophysical Research, Vol. 90, pp. 5547-5566, 1985.
72. Ramanathan, V., "Greenhouse Effect Due to Ch 1 orofluorocarbons: Climatic Implications," Science,
Vol. 190, p. 50, 1975.
73. Daly, J. J,, Jr., The Properties and Toxicology of Alternatives to CFCs, E. I. Du Pont dc Nemours and
Company, Wilmington, DE, October 1989.
74. Rubenstein, R, "Human Health and Environmental Toxicity Issues for Evaluation of Halon
Replacements." In: Proceedings of the Halon Alternatives Technical Working Conference 1992,
Albuquerque, NM, 1992. p. 70 (Abstract).
75. Lu, G. G., Ling, J. S. L., and Krantz, J. C . Jr., "Anesthesia XLI: The Anesthetic Properties of Certain
Fluonnated Hydrocarbons and Ethers," Anesthesiology, 14:466-472, 1953.
76. van Poznak, A., and J. F. Artusio, Jr., "Anesthetic Properties of a Series of Fluorinated Compounds. I.
Fluorinaled Hydrocarbons," Toxicology and Applied Pharmacology, 2:363-373, 1960.
77. Artusio, J. F., Jr., and van Poznak, A., "Laboratory and Clinical Investigation of Teflurane, 1,1,1,2-
Tetrafluoro-2-bromoethane," Federation Proceedings, 20(1):312, 1961.
78 Burns, T, H. S., Hall, J. M., Bracken, A., and Gouldstone, G., "Fluorine Compounds in Anesthesia (5).
Examination of Six Heavily Halogcnatcd Aliphatic Compounds," Anesthesia, 17:337-343, 1962,
67
-------
79 Fabian, L. W., dc Witt. H., and Carnes, M. A., "Laboratory and Clinical Investigation of Some Newly
Synthesized Fluorocarbon Anesthetics," Anesthesia and Analgesia Current Research, 39; 456-462, 1960.
80 Stephen, C. R., and North, W. C., "Halopropane—A Clinical Evaluation," Anesthesiology, 25 (5): 601-
606, 1964.
81 Lester, D., and Greenberg, L. A., "Acute and Chronic Toxicity of Some Halogenated Derivatives of
Methane and Ethane," Archives of Industrial Hygiene and Occupational Medicine, 2:335-344. 1950.
82. Matovinovic, J., "Iodine," In: Nutrition Reviews' Present Knowledge in Nutrition (fifth edition). The
Nutrition Foundation, Inc., Washington, DC, pp. 587-606, 1984.
83. Mathewson, H. S, Structural Forms of Anesthetic Compound's, Charles C. Thomas, Springfield, IL, 1961.
84. Krantz, J. C., Jr., Lu, G. G., Speers, L., Rudo, F. G., and Cascorbi, H.F., "Anesthesia LXV. The
Anesthetic Properties of 2,2,2-Trifluorocthyl Iodide," Anesthesia and Analgesia Current Research, 42:12-
18, 1963.
85. Hine, J., and Ghirardelli, R. G., "The Sn2 Reactivity of B-fluroethyl Iodides," Journal of Organic
Chemistry, 23:1550-1552, 1958.
86. Sokoloff, L, "Local Blood Flow in Neural Tissue." In: New Research Techniques of Neuroanatomy, W.
F. Windlc, ed., Symposium Sponsored by the National Multiple Sclerosis Society, Springfield, IL,
pp. 51-61, 1957."
87. Burns, T. H. S., Hall, J. M., Bracken, A., and Gouldstone, G, "Fluorine Compounds in Anesthesia,"
Anaesthesia, 37:278-284, 1982.
88. Krantz, J. C., Jr., and Rudo, F. G., "The Fluorinated Anesthetics." In: Handbook of Experimental
Pharmacology, F. A. Smith, ed., Springer-Verlag, West Berlin, Federal Republic of Germany, XX/I:
501-564, 1966.
89. Di Paolo, T., and Sandorfy, C„ "Hydrogen Bond Breaking Potency of Fluorocarbon Anesthetics," Journal
of Medicinal Chemistry, 17(8):809-814, 1974.
90. Ulm, K, "Screening Results on the Toxicity of Numerous Fluoro Organic Compounds," Abstracts of the
International Symposium on Fluorine Chemistry in Paris, p. 252, 1986.
91. Probst, A., Raab, K., Ulm, K., and von Werner, K„ "Synthesis and Chemistry of Perfluoro-2-iodo-2-
methyl Alkanes ."Journal of Fluorine Chemistry, 37:223-245, 1987.
92. van Poznak, A., and Atrusio, J. F., Jr., "Laboratory and Clinical Studies with l,l,2-Trifiuro-2-bromoethyl
Methyl Ether." In: Federation Proceedings, 20(1 ):312, 1961.
93. Simons, C. W., O'Neill, G. J,, and Gribens, J, AAerosol Propellant for Personal Projects, U.S. Patent
4,139,607, 1979.
94. Park, C. S., Tniitt, E. B., and Krantz, J. C., "Anesthesia, LI.. A Comparative Study of Ethylvinvl and
Trifluoroethy]vinyl EtheTS "Anesthesiology, 18:250-256, 1957.
68
-------
95. Musscr, R. D,, Park, C, S., and Krantz, J. C., "Anesthesia. LVI. Stability of Trifluoroethyl Vinyl and
Ethylvinyl Ethers in the Animal Body," Anesthesiology, 18:480-482, 1957.
96. Burns T. H. S., Hall, J.M., Bracken, A., and Gouldstone, G., "An Investigation of New Fluorine
Compounds in Anesthesia (4)," Anesthesiology, 16:440-444, 1961.
97. Krantz, J. C., Jr., Cascorbi, H. F., Helvich, M., Burgison, R. M., Gold, MI., and Rndo, F. G., "A Note on
the Intravenous Use of Aesthetic Emulsions in Animals and Man with Special Reference to
Mclhoxyfluranc," Anesthesiology, 22: 491-492, 1961.
98. Rudo, F. G, and Krantz, J. C., "Induction Anesthesia with Intravenous Emulsions." In: Federation
Proceedings, 22:187, 1963.
99. Clayton, W. J., Jr., "Fluorocarbon Toxicity and Biological Action," Fluorine Chemistry Reviews,
1(2): 197-252, 1967.
100. Cook, E. W., and Pierce, J. S., "Toxicology of Fluoro-olefins," Nature, 242:337-338, 1973.
101. Krespan, C. G., "Organic Fluorine Chemistry," Science, 150.13, 1965.
102. Abreu. B. E., "Unsaturated Mono Halogenated Hydrocarbons as General Anesthetics," Anesthesiology,
2:393-397, 1941.
103. Henschler, D. "Halogenated Alkenes and Alkynes," In: Bioactivation of Foreign Compounds, Academic
Press, Inc., New York, pp. 317-347, 1985.
104. Eder, E., Neudccker, T., Lutz, D., and Henschler, D., "Correlation of Alkylating and Mutagenic Activities
of Allyl and Allylic Compounds: Standard Alkylation Test vs. Kinetic Investigation," Chemical-
Biological Interactions, 38:303-315, 1982.
105. Clayton, J. W., "Toxicology of the Fluoroalkenes: Review and Research Needs," Environmental Health
Perspectives, 21:255-267. 1977.
106 Burgison, R. M., O'Malley, W. E.. Heisse, C. K., Forrest, J. W., and Krantz, J. C . Jr., "Anesthesia XLVI.
Flourinated Ethylenes and Cardiac Arrhythmias Induced by Epinephrine," Journal of Pharmacology and
Experimental Therapeutics, 114:479-490, 1955.
107. Neudecker, T., Lutz, D., Eder, E., and Henschler, D., "Structure-Activity Relationship in Halogen and
Alkyl Substituted Allyl and Allylic Compounds: Correlation of Alkylating and Mutagenic Properties,"
Biochemical Pharmacology, 29:2611 -2617,1980.
108. Eder, E., Neudecker, T., Lutz, D., and Henschler, D., "Mutagenic Potential of Allyl and Allylic
Compounds," Biochemical Pharmacology, 29:993-998, 1980.
109. Cohen, E. N., Brewer, H. W., Bellville, J. W., and Slier. R., "The Chemistry and Toxicology of
Dichlorohexafluorobutcne," Anesthesiology, 26:140, 1965.
69
-------
110. Chcnowclh, M. B., "Communication of the Toxicity of 2.3-Dichloro-l, 1, 1,4,4,4-hexafluorobutene-2 to the
National Research Council," Subcommittee on the National Halothane Study of the Committee on
Anesthesia. Washington, DC, 1963.
111. Raventos, J,, and Lemon, P. G., "The Impurities in Fluothane: Their Biological Properties," British
Journal of Anesthesia, 37:716, 1965.
112. Pope, P. R , "North Slope Oilfield Fire Protection; The Halon Issue." Proceedings of the International
Conference on CFC and Halon Alternatives, Washington, DC. October 1989.
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APPENDIX A
DEFINITIVE RULES FOR NAMING AND NUMBERING HALOALKANES
NAMING HALOALKANES
In the International Union of Pure and Applied Chemistry (IUPAC) naming system, each substitucnt must
have a number indicating its position, unless no ambiguity is caused by omitting the number. If more than one of a
particular type of substitucnt is present, the prefixes di-, tri-, tetra-, penta-, etc., are used. For example,
fluoroethane (CH3CH2F) does not require numbering, whereas 1,2-dibromoethane (CH2BrCH2Br) does—to
distinguish it from 1,1-dibromoclhanc (CHBr2CH3).
The carbon chain is numbered in such a way as to give the lowest sum of numbers to the substitucnts. For
example, the molecule
CI II CI
II - C - C - C - H
H CI CI
is named 1,1,2,3-tetrachloropropane (numbered from the right), not 1,2,3,3-tetrachloropropane. If the numbering
(and therefore the sum of substitucnt numbers) is the same from either end, the first group alphabetically takes
priority. For example,
F - CH2 - CH2 - I
is named l-fIuoro-2-iodoethane (not 2-fluoro-l -iodocthane) Similarly, because chlorine comes before fluorine in
the alphabet,
F
i
CI
i
CI
i
1
C -
i
1
C -
i
1
C - F
i
1
H
1
H
1
H
is designated 1,2-dichloro- 1,3,3-trifluoroethane (not 2.3-dichloro-l, 1,3-trifhioroethane) even though the set of
numbers is the same (1,1,2,3,3) from either end of the molecule.
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Prefixes such as di-, tri-, and tetra- are ignored in the alphabetization of subslituents. These prefixes are
inserted after the substituent names such as bromo, chloro, fluoro, and iodo have been alphabetized. Therefore,
bromo always conies before chloro, no matter how many of each are present. For example, the compound
Br CI
Br - C - C - CI
H Br
is named 1,2,2-tribromo-U-dichloroethane (not l,l-dichloro-l,2.2-tribromocthane).
If a conflict in priority between numbering and alphabetization occurs, numbering takes precedence. The
carbon atoms are numbered to give the lowest set of substituent numbers, instead of the lowest carbon number
going to the carbon with the first alphabetical substituent. For example, the compound
H F
I I
CI - C - C - F
I I
CI F
is called 2,2-dichIoro-l,l,l-trilluoroethane; the lowest set of numbers takes priority in numbering the carbon
atoms. It would be incoirect to name this compound 1, l-dichIoro-2,2,2-trifluorocthane and thus give priority in
numbering carbon atoms to the substituent names.
The prefix ger indicates that every possible site on the carbon skeleton is occupied by the same type of
substituent. For example, perfluorocyclopentane is
F F
\ /
F C F
\ / \ /
F - C - C - F
I I
F - C - C - F
I I
F F
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NUMBERING HALOALKANES
In the halocarbon (also known as CFC or Frcon) numbering system, the first number gives the number of
carbon atoms minus one, followed by (in order) the number of hydrogen atoms plus one and the number of fluorine
atoms.
All remaining atoms are assumed to be chlorine atoms. An initial zero (indicating a one-carbon
compound) is omitted. For example, CFC-12 has one carbon (initial zero dropped), no hydrogen atoms (0 + 1 =
1), two fluorine atoms and, by default, two chlorine atoms, for a formula CF2C12- Halocarbon 113 is CF3CC13 or
one of its isomers. Note that several isomers may have identical halocarbon numbers. To distinguish these
isomers for ethane derivatives, a letter is added based on the symmetry of the molecule. For two-carbon
compounds, the absence of a letter indicates the most symmetrical isomer, while an "a" indicates the next most
sy mmetrical isomer, "b" the next, etc. The symmetry is determined by adding the atomic masses of the substituents
on each carbon atom. The isomer with the smallest difference in the sum of the masses on the two carbon atoms
receives no letter, the next smallest difference receives an "a", the next a "b". and so on. For example
first digit
number of carbon atoms -1
second digit
number of hydrogen atoms + 1
third digit
number of fluorine atoms
F F
CI - C - C - CI is Halocarbon 132
H H
CI F
while
CI - C - C - F is Halocarbon 132a
H H
F H
CI - C - C - CI is Halocarbon 132b
F H
73
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CI H
and CI - C - C - F is Halocarbon 132c
F H
For cyclic compounds, the prefix C precedes the halocarbon number. For example, perfluorocvclobutane
(cyclo-C4Fg) is Halocarbon C318.
If bromine is present in the molecule, it is numbered as if the bromine atoms were chlorine atoms; the
designation "Bn" is added to the end of the halocarbon number, where "n" is the number of bromine atoms. For
example, the anesthetic Halothane (CF3CHBrCl) is Halocarbon 123aBl. Two carbon atoms minus one gives the
initial 1, followed by a 2 for one hydrogen atom plus one, followed by a 3 for three fluorine atoms. The "a"
indicates the second most symmetrical isomer (if the chlorine atom were switched for one of the fluorine atoms, the
molecule would be the most symmetric); the final MB1" means that one of the clilorine atoms was replaced with a
bromine.
Although the halocarbon numbering system is the same, two letters are required to specify the isomer for
three-carbon compounds (propancs). The first letter refers to the central carbon atom of the propane. To assign
this letter, one calculates the combined atomic mass of the substituents on this carbon atom. The first letter is then
assigned to the higher atomic mass,
a = -CC12- d = -CHCI-
b = -CC1F- e = -CHF-
c = -CF2- f = -CIV
The second letter refers to the terminal carbon atoms. This letter is determined by finding the difference
in the combined atomic masses of the substituents on these two carbon atoms. The smallest difference is assigned
the letter "a". This differs from the two-carbon compounds, in which the smallest difference has no letter. For
Ihree-carbon compounds, the second biggest difference is assigned the letter "b", followed by "c", "d", and so on.
For example, CIIC12CF2CF3 (3,3-dichloro-I,l,l,2,2-penlafluoTopropane) is designated Halocarbon 225ca. Its
isomer CHC1FCF2CC1F2 (1,3-dichloro-1,1,2.2,3-pentafluoropropane) is 225cb.
Note that the term "halocarbon number" is used in preference to the terms CFC or Freon number in this
description because the name Freon is a registered trademark and CFC refers strictly to fully halogenated
chlorofluorocarbons. The more general term "halocarbon" includes (in addition to CFCs) the HCFCs,
bromofluorocarbons (BFCs), hydrobromofluorocarbons (HBFCs), bromochlorofluorocarbons (BCFCs), and
hydrobromochlorofluorocarbons (HBCFCs), as well as iodinated compounds.
74
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Alternatively, the halon numbering system lists in order the number of cart>on, fluorine, chlorine, bromine
and iodine atoms. Trailing zeros are dropped. Thus Halon 12 is CH2F2, and Halon 23011 is CBrF2CHFI or one of
its isomers. The halon numbering system does not include a method for specifying isomers.
CGET/NMERI has developed a computer code written in BASIC language that determines the 1UPAC
name, halocarbon number, halon number, and molecular weight from the structural formula. In addition, the
program corrects the sequence of atoms in the structural formula, if input is in error.
75
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APPENDIX B
REGULATORY CONCERNS
INTRODUCTION
Several national environmental regulations are being taken into consideration throughout this project. In
general, these regulations are designed to protect human health and the environment, specifically the air, surface and
ground waters, the firefighter, and the surrounding communities with which candidate agents and their combustion
emissions are likely to come into contact. This appendix summarizes the most pertinent environmental regulations
with respect to the initial lists of physical action agents (PAAs) and chemical action agents (CAAs) (Tables 2 and 8).
Regulatory concerns will be investigated throughout the project so that the final candidate replacement agents will
meet or exceed regulatory requirements.
MONTREAL PROTOCOL
Approximately 140 countries are currently Parties to the Montreal Protocol on Substances that Deplete the
Ozone Layer. The Montreal Protocol is a landmark international treaty designed to protect the stratospheric ozone
layer by controlling the consumption of ozone depleting chemicals. Consumption is defined as production minus
exports plus imports. The original provisions under the Protocol control fully halogenated CFCs (11, 12, 113, 114,
and 115) and halons (1211, 1301, and 2402). Due to increased scientific concerns about the ozone depletion that has
already occurred and the associated health and environment effects, the Protocol was strengthened in London during
June 1990. At the London meeting, the Parties to the Protocol agreed to an accelerated phaseout of currently
controlled CFCs and halons by the year 2000. The Parties also established phaseout schedules for other fully
halogenated chlorofluorocaibons, methyl chloroform, and carbon tetrachloride. Table B-l summarizes the new
phaseout schedule and additional compounds included as a result of the London Meeting. Several PAAs that will
e%'entually be controlled under the Protocol are shown in this table; however, controls are not expected to go into
effect until 2020.
Copenhagen Amendments
The Fourth Meeting of the Parties to the Protocol was held in Copenhagen, Denmark, 23-25 November
1992. At that meeting, the Parties agreed to accelerate the phaseout schedule for certain controlled substances,
including halons. Moreover, three groups of chemicals were added: Annex C, Group I contains HCFCs; Annex C,
Group II contains HBFCs (Table B-2); and Annex E, Group I contains only methyl bromide (ODP = 0.7). The
76
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TABLE B-1. SUMMARY OF AMENDMENTS TO THE MONTREAL PROTOCOL,
PASSED JUNE 1990*
ORIGINAL CONTROLLED SUBSTANCES
Group!: CFC-11, -12, -113, -114,-115 (1986 base year)
1987 Protocol 1990 London Meeting
July 1990 1986 levels 1993 80%
1998 50% of 1986 levels 1995 50%
1997 15%
2000 0%
Group II: Halons 1211,1301, 2402 (1986 base year)
1992 1986 levels 1995 50%
2000 0% (except for essential uses)
ADDITIONAL SUBSTANCES
Group I: Additional fully halogenated compounds scheduled for phaseout:
CFC-13, -111, -112, -211, -212, -213, -214, -215, -216, -217 (1989 base year)
1993 80%
1997 15%
2000 0%
Group II: Carbon tetrachloride (1989 base year)
1995 15%
2000 0%
Group III: Methyl chloroform (1989 base year)
1993 Freeze production
1995 70%
2000 30%
2005 0%
Group IV: HCFCs - Hydrochlorofluorocartoons: Phaseout 2020-2040
*This timetable is applicable for developed nations; it is extended for developing countries.
77
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TABLE B-2. ANNEX C, GROUP II, MONTREAL PROTOCOL AS AMENDED IN 1992
Formula
Number of isomers
Ozone-depletion potential*
CHBr2F
1
1.00
CHBrF2
1
0.74
CH2BrF
1
0.73
C2HBr4F
2
0.3-0.8
C2HBr3F2
3
0.5-1.8
C2HBr2F3
3
0.4-1.6
C2HBrF4
2
0.7-1.2
C2H2Br3F
3
0.1-1.1
C2H2Br2F2
4
0.2-1.15
C2H2BrF3
3
0.7-1.6
C2H3FBr2F
3
0.1-1.7
C2H3BrF2
3
0.2-1.1
C2H4Brf
2
0.07-0.1
C3HBr6F
5
0.3-1.5
C3HBrsF2
9
0.2-1.9
C3HBr4F3
12
0.3-1.8
C3HBr3F4
12
0.5-2.2
C3HBr2F5
19
0.9-2.0
C3HBrF6
15
0.7-3.3
C3H2BrsF
9
0.1-1.9
C3H2Br4F2
16
0.2-2.1
C3H2Br3F3
18
0.2-5.6
C3H2Br2F4
16
0.3-7.5
C3H2BrF5
18
0.9-14
C3H3Br4F
112
0.08-1.9
C3H3Br3F2
18
0.1-3.1
C3H3Br2F3
118
0.1-2.5
C3H3BrF4
112
0.3-4.4
C3H4Br3F
112
0.03-0.3
C3H4Br2F2
116
0.1-1.0
C3H4BrF3
112
0.7-0.8
CsHsBr^
9
0.04-0.4
C3H5BrF2
9
0.07-0.8
C3H6BrF
5
0.02-0.7
* ODPs listed as a range are estimated and give the highest and lowest values for a
series of isomers. Individual values are rigorously calculated. Regulations will be
based on the highest value in a range.
78
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addition of Group II to die Protocol restricts the use of any HBFC being considered in the effort. Therefore, the
production of HBFCs listed in Table 8 will be regulated under the Montreal Protocol.
Restrictions—
A breakdown of the restrictions on ozone-depleting chemicals under the amendment to the Montreal
Protocol agreed to at the Fourth Meeting of the Parties in Copenhagen in November 1992 is outlined in Table B-3.
Consumption restrictions prior to 1994 remain the same as those established by the Montreal Protocol as amended in
1990. For all chemicals except HCFCs, up to 10 or 15 percent (depending on the chemical and the stage of
restriction) above the restricted amounts may be produced by developed countries for countries operating under
Paragraph 1 of Article 5 (developing countries). The levels may also be adjusted to allow for essential uses. The
restrictions are postponed for Article 5 countries.
Because the IICFC base is ODP-weighted, each government must decide how to allocate its HCFC con-
sumption, For example, a country could choose to produce larger amounts of low-ODP HCFCs (such as HCFC-123),
smaller amounts of high ODP HCFCs (such as HCFC-22 or HCFC-141b), or some balance between the two.
TABLE B-3. CONSUMPTION CUTS UNDER COPENHAGEN AMENDMENT*
Year*
CFC
Halons
Methyl
Cartoon
Methyl
HCFC
HBFC
<%)
(%)
chloroform
(%)
tetrachloride
(%)
bromide
(%)
(%)
(%)
1994
75
100
50
1995
85
Cap
1996
100
100
100
Cap
100
2004
35
2010
65
2015
90
2020
99.5
2030
100
* Base years: (CFCs 1986 (in original Protocol), 1989 (in 1990 amendment); halons 1986; methyl
chloroform and carbon tetrachloride 1989; methyl bromide 1991. Base for HCFCs is 1989
ODP-weighted HCFC consumption plus 3.1% of 1989 ODP-weighted CFC consumption.
* Beginning 1 January of year cited, annual consumption amounts must meet the proscribed cuts.
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Essential Uses—
At the Copenhagen meeting, the Parties agreed to allow for an exemption of essential uses of controlled
substances from the consumption phaseout schedule. Specific essential-use exemptions for halons were considered at
the Fifth Meeting of the Parties in Bangkok, Thailand, which was held on 15-24 November 1993. Essential-use
exemptions for halons (again) and the remaining substances were also considered at the Sixth Meeting of the Parties
in Nairobi. Kenya, on 6-7 October 1994. As a result of the two meetings, exemptions have been granted only for
CFCs in metered dose inhalers and for CFC-113 and methyl chloroform in the space shuttle. The decision at the
Copenhagen meeting was that a controlled substance should qualify as essential only if the following two criteria arc
met; (1) it is necessary for health and safely, or is critical for the functioning of society (encompassing cultural and
intellectual aspects), and (2) there are no available technically and economically feasible substitutes acceptable from
the standpoint of environment and health.
The Parties also agreed, at the Copenhagen meeting, that production and consumption, if any, of a
controlled substance for essential uses should be permitted only if all economically feasible steps have been taken to
minimize the essential use and any associated emission of the controlled substance. Furthermore, the controlled
substance is not available in sufficient quantity and quality from the existing slocks of banked or recycled controlled
substances.
Entry Into Force--
The 1992 amendment to the Montreal Protocol became effective on 1 January 1994.
FEDERAL CLEAN AIR ACT AND THE AMENDMENTS OF 1990
In the United States, Title VI of the newly amended Clean Air Act (CAA) includes stringent provisions for
stratospheric ozone protection. Like the Montreal Protocol, the CAA requires a complete production phaseout of
CFCs, carbon tetrachloride, and all but essential halons by the year 2000; however, interim reductions under the
CAA for these substances are more stringent. In addition, Congress has enacted an excise tax on ozone-depleting
chemicals based on their ozone-depletion potential. An overview of the CAA follows.
The CAA, as originally enacted in 1970 and amended in 1977 and 1990, includes a number of programs
intended to clean up unhealthful levels of pollution and preserve air quality in areas with pristine air. National
Ambient Air Quality Standards are set for several air contaminants from sources such as automobiles, power plants,
and industrial facilities. Congress became concerned about the ozonc-dcplction issue in 1976; therefore, the 1977
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Amendments to the Act added a regulatory scheme designed to regulate certain halocarbons considered as ODCs. It
also required numerous federal agencies to participate in studies of the ozone-depletion problem and generate
comprehensive reports detailing the issue. During this same time frame, EPA used its authority under the Toxic
Substances Control Act (TSCA) to regulate the use of halocarbons as aerosol propellants. Congress mandated in the
1977 Amendments that this activity should go on without interference from other intra-agency officials, but made it
clear that future regulation of ozone-depleting substances would be under the CAA.
Title VI of the 1990 Amendments repealed the "Ozone Protection" provisions of the 1977 Amendments and
added the new Title VI - Statospheric Ozone Protection provisions. Title VI listed ozone-depleting substances as
either Class 1 (with Groups 1 through V) or Class II (Table B-4). Class I compounds are essentially those with an
ODP of 0.2 or gTeater. Consumption phaseout schedules are pro%ided for the Class I substances. Their production
will be unlawful effective 1 January 2000 (1 January 2002 in the case of methyl chloroform) (Table B-5). Certain
exemptions are, however, noted. With respect to this project, and to the extent consistent with the Montreal Protocol,
the 1990 Amendments authorize the production of limited quantities of Halons 1211, 1301, and 2402 in the period
"after 31 December 1999, and before 31 December 2004, solely for purposes of fire suppression or explosion
prevention in association with domestic production of crude oil and natural gas energy supplies on the North Slope of
Alaska," provided no safe and effective substitutes are available. Title VI authorizes the amount shall be no greater
than 240,000 pounds total for Halon 1301 (3 percent of 1986 production levels). Preliminary figures indicate the
average North Slope Halon 1301 consumption is approximately 250,000 pounds per year (112). This reported
annual consumption exceeds the authorized maximum by 10,000 pounds, demonstrating the need for replacement
agents within the next 10 years.
Production/consumption reduction requirements for the Class 11 substances (Table B-4) will become
effective 1 January 2015 with a total phaseout scheduled for 1 January 2030 (Table B-5). Again, production
exemptions are discussed. Provision also exists in Title VI whereby the EPA Administrator can add compounds to
the existing list of controlled substances and accelerate the phaseout schedule. Accelerated schedules are provided
for in the event that the Montreal Protocol is modified, alternate substitutes for the listed substances become
available, or if a "more stringent schedule may be necessary to protect human health and the environment."
Table B-4 shows those candidates included in Title VI of the CAA Amendments of 1990. Several PAAs
(Table 2) fall into the Class II designation, which means production and consumption phaseouls under the CAA can
be expected in 2015, or possibly sooner. These chemicals include HCFC-22, -124, -124a, -142a, -142b, -226ba, all
235 isomers and all 244 isomers.
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TABLE B-4. CHEMICALS LISTED IN TITLE VI OF THE CLEAN AIR ACT AMENDMENTS OF 1990
CLASS I (includes the isomers of the substances listed, other than 1,1,2-trichloroethane [an isomer of methyl
chloroform])
GROUP I Chlorofluorocarbon (CFC>-11, -12, -113, -114,-115
GROUP II Halons 1211, 1301, 2402
GROUP III CFC-13. -111, -112, -211, -212, -213, -214, -215, -216, -217
GROUP IV Carbon tetrachloride
GROUP V Methyl chloroform
CLASS II (includes the Isomers of the substances listed)
Hydrochlorofluorocarbon (HCFC)-21, -22*, -31, -121, -122, -123, -124*, -
131, -132, -133, -141, -142*, -221, -222, -223, -224, -225, -226*, -231, -232,
-233, -234, -235*. -241, -242, -243, -244*. -251, -252, -253, -261, -262, -271
'Candidates included in Table 2.
TABLE B-5. SUMMARY OF PRODUCTION LIMITS UNDER TITLE VI OF THE CLEAN AIR ACT
AMENDMENTS OF 1990
CLASS I SUBSTANCES
Dale
Carbon tetrachloride
(% 1989 base year)
Methyl chloroform
(% 1989 base year)
Compounds with an ODP greater
than 0.2 (1986 base year)
1991
100
100
85
1992
90
100
80
1993
80
90
75
1994
70
85
65
1995
15
70
50
1996
15
50
40
1997
15
50
15
1998
15
50
15
1999
15
50
15
2000
0
2)
3 for halons
2001
0
20
3 for halons
2002
0
0
3 for halons
2004
0
0
Exemptions cease
CLASS I
1 SUBSTANCES: COMPOUNDS THAT DEPLETE STRATOSPHERIC OZONE
(base year to be selected by the EPA Administrator)
2000
EPA Administrator to promulgate regulations phasing out production and restrictions on use of ODCs.
2015
100 (% base year)
2030
0 (% base year)
2040
Exemptions cease.
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Title VI also provides for a National Recycling and Emission Reduction Program for ozone-depleting substances, as
well as servicing requirements for motor vehicle air conditioners, elimination of nonessential products containing
CFCs, and container labeling requirements. A Safe Alternatives Policy requires the Administrator to provide
consultation and coordination in developing alternatives, recommending measures to promote transition by the
Federal Government to the use of safe substitutes, and to maintain a public clearinghouse of alternative chemicals
and processes. Under Section 612, a list of prohibited substitutes and safe alternatives for specific uses were
developed in January 1993. Federal procurement requirements, international cooperation, technology transfer,
assistance to developing nations, and enactment of methane emission studies are also included in Title VI.
In summary, non-zero ODP chemicals will require substitution sometime in the future. To meet the long-
term provision of the CAA, halon alternatives must have a veiy near zero ODP. Thus, the attention in the physical
action segment of the project has focused on FCs and HFCs.
Significant New Alternatives Policy (SNAP)
Section 612 of Title VI of the Clean Air Act Amendments (CAAA) of 1990 requires that the EPA enact
regulations making it unlawful to replace any Class I or Class II regulated substance with any substitute that may
impact human health or the environment. This section of the CAAA also prohibits the use of a substitute where
another available substitute has been identified that provides a lower risk to human health and the environment. In
addition, Section 612 requires the EPA to publish lists of both acceptable and prohibited substitutes. Risk
assessments are required to be conducted under the SNAP program. Key risk criteria identified under the SNAP
program include the following:
• Atmospheric Chlorine Loading
• Ozone-Depleting Potential (ODP)
• Global-Wanning Potential (GWP)
• Toxicity to Human Health and Ecosystems
• Air, Water, and Solid/Hazardous Waste Impacts
• Exposure to Workers, Consumers, General Population, and Ecosystems
• Flammability
In accordance with these SNAP guidelines, the most important environmental concerns are ODP, GWP, and
other classic environmental waste issues. Table B-6 provides a compilation of the information being considered on
candidate replacement agents. Toxicity of the candidates is addressed later in this section. Exposure of workers,
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TABLE B-6. ENVIRONMENTAL CONCERNS UNDER SNAP
Name
Fofmula
Chlorine
loading
Ozone-depletion
potential
Atmospheric life
Waste issues*
Flat
HYDROBROMOFLUOROCARBONS
Dibromofliforomethane
CHBr2F
0
<0.2 estimated
Unknown
Unknown
No
1,2-Dibromo-1,1,2-trlfluoroethane
CBrF2CHBrF
0
>0.2 estimated
Unknown
Unknown
No
2,2-Dlbronoo-1,1,1 -trifluoroethane
CHBr2CF3
0
<0.2 estimated
Unknown
Unknown
No
2,3-Dibroiro-1,1,1 -trifluoropropane
CF3CHBrCH2Br
0
>0.2 estimated
Unknown
Unknown
No
Bromodl ftuoromethane
CHBrF2
0
1.37
Unknown
Unknown
No
2-Bromo-1,1,1,2-tetrafluoroethane
CF3OHBrF
0
0.44
Unknown
Unknown
No
Ftammability
FLUOROIODOCAR BONS
T rifluoroiodomethane
Difluoroiodomethane
F luoroiodomethane
Pentafluoroiodoethane
Perfluoro-n-propyl iodide
Perfluoro»sopropy1 iodide
Perfluoro-n-butyl iodide
Perfluoro-n-hexyl iodide
Perfluofo-n-octyl Iodide
CF3I
chf2i
ch2fi
CF3CF2i
CF3CF2CF2!
CF3CFICF3
CF3CF2CF2CF2!
CF3(CF2)4CF2I
CF3(CF2)6CF2l
low?
low?
low?
low?
low?
low?
low?
low?
low?
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
No
No
Likely
No
No
No
No
No
No
HALOETHERS
Perfluorodimethyl ether
Methyl Trifluoromethyl ether
Difluoromethyl fluoromethyl ether
1,1,2,2-Tetrafluoro-dimethyl ether
T rifluoromethyl difluoromethyl ether
Trifluoromethyl pentafluoroethyl ether
Perfluoroxetane
1,12,2-Tetrafluoroethyl difluoromethyl ether
1,1,1 -Trlfluocolsopropyl trifluoromethyl ether
CF3OCF3
ch3ocf3
CHF20CH2F
CHF20CHF2
CF30CHF2
CF3OCF2CHF2
-cf2cf2cf2o-
CHF20CF2CHF2
CF3(CH3)CHOCF3
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Long
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
No
Likely
Likely
No
No
No
No
Lkely
No
(continued)
-------
TABLE B-6. (conducted)
Name
Formula
Chlorine
loading
Ozone-depletion
potential
Atmospheric If*
Waste issues*
Flammability
1,1,1 -T rifluoroethyt difluromethyl ether
cf3ch2ochf2
0
0
Unknown
Unknown
No
1,1-Difluoroethyl fluoromethyl ether
CHF2CH2OCH2F
0
0
Unknown
Unknown
Likely
Perfluorodiroethoxymetbarie
CF3OCF2OCF3
0
0
Unknown
Unknown
No
Difluoromethyl bromod id uoromethyl ether
CHF20CBrF2
0
Estimated
Unknown
Unknown
No
Tiifluoromethyl bromod ifluorom ethyl ether
CF3OCBrF2
0
Estimated
Unknown
Unknown
No
Difluoromethyt bromotetrafluoroethyl ether
CHF2OCF2CBrF2
0
Estimated
Unknown
Unknown
No
Methyl bromod rfluoromettiyl ether
CH30CBrF2
0
Estimated
Unknown
Unknown
No
BROMOFLUOROALKENES
3-Bromo-3,3-difluoropropene
CH2=CHCBrF2
0
llow/estlmated
Unknown
Unknown
Unknown
3-(Bromodifluoromethyl)-3,4,4,4-
CH2=CHC
-------
consumers, general populations, and ecosystems depends on the agent application and is beyond the scope of this
document. Information on GWP is unavailable on all of the compounds. In an attempt to address the topic of global
warming, data on atmospheric lifetimes of the compounds were collected where available to provide an indication of
the impact a candidate might have on global warming.
To date, no verifiable ODP values have been calculated for brominated alkenes or iodinated fluorocarbons.
Preliminary indications suggest that bromoalkenes may have zero ODPs. The ODPs of fluoroiodocaibons are
completely unknown. Nonetheless, the photolytic sensitivity of iodine-containing compounds suggests that the ODP
of these materials may be very low.
RESOURCE CONSERVATION AND RECOVERY ACT
The "cradle to grave" management requirements for hazardous waste generators and transporters, and
operators of treatment, storage, and disposal facilities are covered under the Resource Conservation and Recovery Act
(RCRA) enacted on 21 October 1976. RCRA was the first comprehensive federal effort to deal with the problems
associated specifically with solid and hazardous wastes. Wastes are covered by RCRA if they possess one of four
characteristics: ignitability, corrosivity, reactivity, and/or extraction procedure toxicity. None of the physical action
agents listed in Table 2 has these characteristics, and is therefore not listed under RCRA. Thus, the regulation should
not apply.
COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION, AND LIABILITY ACT
The Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), also known as
Superfund, was passed by Congress and signed into law on 11 December 1980. This statute provides federal funding
to respond to various releases of hazardous substances to the environment. Funds are provided for the immediate
cleanup of hazardous waste contamination from an accidental spill or from chronic environmental damage such as
that associated with an abandoned hazardous waste site. The National Contingency Plan, the National Priorities
Lists, and other cleanup activities fall under CERCLA.
Section 101(4) of CERCLA defines hazardous substances as follows: (1) designated "hazardous" under
Section 311 of the Clean Water Act (CWA); (2) listed wastes under RCRA; (3) any toxic pollutant listed under
Section 307(a) of the CWA; (4) any hazardous air pollutant listed under Section 112 of the CAA; (5) any imminently
hazardous chemical substance for which the EPA Adminstralor has taken action under Section 7 of Toxic Substances
Control Act of 1976 (TSCA); and (6) any other substance EPA designates as hazardous under Superfund
Section 102.
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The reporting of hazardous substance releases falls under CERCLA. Several compounds in the halocarbon
class fall within these guidelines; however, none of the chemicals listed in Table 2 is regulated under CERCLA at
this time.
SUPERFUND AMENDMENTS AND REAUTHORIZATION ACT
The Superfund Amendments and Reauthorization Act (SARA), enacted on 17 October 1986, is a progeny of
CERCLA; it addresses closed hazardous waste sites and environmental releases of hazardous substances. The most
revolutionary part of SARA is the Emergency Planning and Community Right-to-Know Act (EPCRA) covered under
Title III. Under SARA Title III the following must be implemented: (1) appointment of an "emergency response
commission" by the state governors; (2) determination by facilities whether they are subject to Title III requirements;
(3) establishment of slate emergency planning districts; (4) establishment of local emergency planning committees to
prepare an emergency plan; (5) appointment of emergency coordinators; (6) provision by companies of material
safety data sheets (MSDSs) or a list of on-site chemicals in each facility to local and stale committees and fire
departments; (7) annual submittal by companies of invcntoiy and release forms to appropriate authorities; and
(8) preparation by local emergency planning committees (LEPC) of emergency plans containing minimum details.
EPCRA also includes three subtitles: Subtitle A is a framework for emergency planning and release notification;
Subtitle B deals with chemical reporting requiremcnls; and Subtitle C provides for the various penalties for violation
of statutory requirements.
Other provisions of SARA reinforce and/or broaden the basic regulatory program dealing with the releases
of hazardous substances under CERCLA. Section 313 of SARA requires owners and operators of certain
manufacture/process facilities who use one of the 329 listed chemicals and chemical categories to report all
environmental releases on a annual basis. Recently, the CFCs and halons listed under the original Montreal Protocol
and the CAA (CFC-11, -12, -113, -114, and -115 and Halons 1211, 1301, and 2402) were added to the list of
chemicals in Section 313. This makes information about total annual releases of chemicals to the environment
available to the public. None of the chemicals listed in Table 2 requires reporting under SARA al this lime.
TOXIC SUBSTANCES CONTROL ACT
The Toxic Substances Control Act (TSCA) of 1976 provides EPA wilh the authority to require testing of
new and old chemical substances entering the environment and to regulate them as necessary. Testing includes the
determination of the potential environmental and health effects of the chemical prior to large-scale production.
TSCA has two main features: (1) it mandates that EPA musl have enough information to identify and evaluate
potential hazards from chemical substances, and (2) it regulates the production, use, distribution, and disposal of
87
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such substances. EPA used its authority under TSCA as the first attempt at regulating the emissions of ozone-
depleting chemicals (ODCs). In 1977 EPA restricted the use of halocarbons as an aerosol propellant. The principal
provisions of the Act applicable to this project are the Premanufacture Notification (PMN) requirements, the
Inventory List, and Testing Requirements. Each provision will be discussed as it applies to the chemicals described
in this report.
After TSCA was enacted, a list of existing (inventory) chemicals was developed. Any chemical not on the
TSCA Inventory List must undergo PMN requirements. Production quantities of less than 1363 kg (3000 pounds)
per year are considered research and development and listing is not required. Several of the potential candidates are
included on the Inventory List as discussed in the summary portion of this section. Being listed in the TSCA
Inventory does not imply the chemical is toxic, rather that the chemical has been or is currently being produced.
Several of the candidates are currently not commercially available and are not included on the TSCA
inventoiy list; therefore, under TSCA Section 5 a manufacturer will have to notify EPA (i.e.. file a PMN) prior to the
commercial production of such chemicals. Notification also applies to listed chemicals if the EPA Administrator
concludes that a significant new use (based on the Significant New Use Regulations [SNUR]) exists that increases
human or environmental exposure. Upon notification, EPA publishes in the Federal Register a description of the
chemical substance, listing its intended uses, and a description of the toxicological tests required to demonstrate that
there will be "no reasonable risk of injury to health or the environment." The EPA Adminstrator may prohibit the
production of a chemical if insufficient data are available to permit a reasonable evaluation of the risk.
Section 4 of TSCA permits EPA to require testing of a chemical if an unreasonable risk to health or the
environment is suspected or if the chemical is to be produced in quantities such that significant human or
environmental exposure could result. These requirements also apply to mixtures if the effects cannot be predicted by
testing the individual components. EPA selects the toxicological testing necessary to permit production of a
chemical. In general, EPA can require several studies including carcinogenicity, mutagenicity, teratogenicity,
behavioral modification, and synergism. This includes chronic, subchronic, and acute toxicity testing. Because of
the known health effects associated with halocarbons, the chemicals evaluated in this project may likely require
cardiac sensitization, reproductive toxicity, and metabolic effects testing. Toxicity and environmental testing
requirements are generally formally requested by the manufacturer prior to actually evaluating products.
There arc additional provisions which are outlined in TSCA such as reporting requirements, disclosure of
health effects information, relationships to other Acts, prohibited acts, and penalties to name a few. In general,
however, the PMN requirements, the Inventory List, and Testing Requirements are most directly applicable to this
project.
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OCCUPATIONAL SAFETY AND HEALTH ACT
The Occupational Safety and Health Act, enacted in 1970, established the Occupational Safety and Health
Administration (OSHA). The Act was established to assure that "no employee will suffer material impairment of
health or functional capacity" from a lifetime of occupational exposure to chemicals, hazardous substances, or the
like. The Act extends to all employers and their employees in all the states and federal territories. The Act entrusts
OSHA with the major responsibility for workplace safety and health. OSHA has three main roles: (1) setting of
safety and health standards, (2) enforcement through federal and state inspectors, and (3) public education and
consultation.
Safety and health standards are provided by the National Institute for Occupational Safety and Health
(NIOSH). NIOSH publishes the Registry of Toxic Effects of Chemical Substances (RTECS) on an annual basis.
RTECS is a compendium of toxicity data extracted from the scientific literature. The candidate agents listed in
Table 2 were checked against RTECS and applicable information has been included elsewhere in this report.
OSHA requirements applicable to candidate agents will most likely be addressed during the chemical
manufacturing process and agent handling during fire protection system installation, testing, and maintenance.
In general, chemical manufacturers and fire protection service organizations will be responsible for meeting OSHA
requirements. However, introduction of a candidate that exceeds OSHA employee exposure regulations will be
avoided.
CLEAN WATER ACT
In 1972, Congress enacted the Federal Water Pollution Control Act as the basic framework for federal water
pollution control regulation. This Act, significantly modified in 1977 to deal with toxic water pollutants, was
renamed the Clean Water Act (CWA). The Act has five main elements: a permit program, a system of minimum
national effluent standards for each industry, water quality standards, provisions for special problems such as toxic
chemicals and oil spills, and a construction grant program for publicly-owned treatment works. The Act is, of
course, more complex than this five-part framework indicates. Of importance to this project is the fact that none of
the chemicals listed in Table 2 is regulated under in the CWA.
SAFE DRINKING WATER ACT
The Safe Drinking Water Act (SDWA) was enacted in 1974 and amended in 1986 to assure safe drinking
water supplies, protect valuable aquifers, and protect drinking water supplies from underground injection of wastes.
Maximum Contaminant Levels (MCLs) and monitoring requirements are set for several chemicals found in drinking
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water supplies. None of the chemicals listed in Table 2 is regulated under the SDWA of 1986. Also, monitoring
requirements for these chemicals do not apply at this time.
NATIONAL ENVIRONMENTAL POLICY ACT
The National Environmental Policy- Act of 1969 (NEPA) was enacted to declare a national environmental
policy and promote consideration of environmental concerns by all federal agencies. Environmental impact statement
(EIS) requirements are set forth in Title I of NEPA, while Title II establishes a Council on Environmental Quality
(CEQ) to monitor progress toward achieving national environmental quality goals. At present, it has not been
determined whether or not NEPA requirements of a programmatic EIS will apply to the final product of this project.
The EIS question will need to be answered prior to final candidate introduction. Section 102(2)(F) requires all
federal agencies to "recognize the worldwide and long-range character of environmental problems." In the future
this may provide a basis for EPA to consider more scientific data and information to assess the "long-range" effects
of federal actions on the global environment. The information collected during this project on candidates will be
available to assess their impact on the environment. This project will generate information that can be used to
partially fulfill input data for an EIS.
SUMMARY OF REGULATORY CONCERNS
In summary, in new agent development, it is extremely important that release of the chemical to the
environment be addressed, and the final candidate selected be environmentally compatible. Thus, several
environmentally-related regulations have been evaluated and their applicability to the chemicals listed in Table 2 has
been discussed. Throughout this project regulatory concerns will be investigated so that the final candidate(s) will
meet or exceed regulatory requirements. Tables B-7 and B-8 summarize the environmental regulatoiy concerns
related to the physical and chemical action agents being evaluated for this project
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TABLE B-7. REGULATORY SUMMARY OF PHYSICAL ACTION AGENTS
Halocarbon no.
Montreal
Clean Air
RCRA
CERCLA
SARA
TSCA
OSHA
CWA
SDWA
Protocol
Act
regulated
regulated
regulated
listed
regulated
regulated
regulated
Hsrton 1301
Group I
Class I
no
no
yes
yes
yes
no
no
(as reference)
14
no
no
no
no
no
yes
no
no
TO
22
Group IV
Class II
no
no
no
yes
yes
no
no
23
no
no
no
no
no
yes
no
TO
no
31
Group IV
Class II
no
no
no
no
no
no
TO
32
no
no
no
no
no
yes
no
no
no
116
no
no
no
no
no
yes
no
no
no
124
Group IV
Class II
no
no
no
yes
no
no
no
124a
Group IV
Class II
no
no
no
no
no
TO
no
125
no
no
no
no
no
no
no
no
no
134
no
no
no
no
no
no
no
TO
no
134a
no
no
no
no
no
yes
no
TO
no
142a
Group IV
Class II
no
no
no
no
no
TO
no
142b
Group IV
Class II
no
no
no
yes
no
TO
no
143a
no
no
no
no
no
no
no
no
no
152a
no
no
no
no
no
yes
no
TO
no
0216
no
no
no
no
no
no
no
TO
TO
218
no
no
no
no
no
yes
no
TO
TO
226ba
Group IV
Class it
no
no
no
no
TO
TO
no
227ca
no
no
no
no
no
no
no
TO
TO
227ea
no
no
no
no
no
no
no
TO
no
C234
no
no
no
no
no
no
no
TO
no
235da
Group IV
Class II
no
no
no
no
no
TO
no
235cc
Group IV
Class II
no
no
no
no
no
TO
TO
235ca
Group IV
Class II
no
no
no
no
no
TO
no
235ba
Group IV
Class II
no
no
no
no
no
TO
no
235eb
Group IV
Class II
no
no
no
no
no
TO
no
235ea
Group IV
Class II
no
no
no
no
no
no
TO
235bb
Group IV
Class II
no
no
no
no
TO
no
no
236cb
no
no
no
no
no
no
no
TO
no
(continued)
-------
TABLE B-7. (concluded)
Hatooarbon no.
Montreal
Clean Air
RCRA
CERCLA
SARA
TSCA
OSHA
CWA
SDWA
Protocol
Act
regulated
regulated
regulated
Irsied
regulated
regulated
regulated
236fa
no
no
no
no
no
no
no
no
no
244cfo
Group IV
Class II
no
no
no
no
no
no
no
244da
Group IV
Class II
no
no
no
no
no
no
no
244fb
Group IV
Class IJ
no
no
no
no
no
no
no
244bb
Group IV
Class 11
no
no
no
no
no
no
no
244ca
Group IV
Class II
no
no
no
no
no
no
no
244cb
Group IV
Class H
no
no
no
no
no
no
no
244ba
Group IV
Class II
no
no
no
no
no
no
no
244eb
Group IV
Class II
no
no
no
no
no
no
no
244fa
Group IV
Class II
no
no
no
no
no
no
no
244ec
Group IV
Class II
no
no
no
no
no
no
no
24Scb
no
no
no
no
no
no
no
no
no
245ea
no
no
no
no
no
no
no
no
no
245eb
no
no
no
no
no
no
no
no
no
245ca
tS 254ea
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
264cb
no
no
no
no
no
i;o
no
no
no
254eb
no
no
no
no
no
no
no
no
no
254fa
no
no
no
no
no
no
no
no
no
254ca
no
no
no
no
no
no
no
no
no
3-1-10
no
no
no
no
no
yes
no
no
no
C318
no
no
no
no
no
yes
no
no
no
-------
TABLE B-8. REGULATORY SUMMARY OF CHEMICAL ACTION AGENTS
Name
Formula
Montreal Protocol and TSCA
Amendments (listed)
CAAA, RCRA, CERCLA, SARA, OSHA,
CWA, SDWA (all regulated)
HYDROBROMOFLUOROCARBONS
Dibromofluoromethane
1.2-Dibromo-1,1,2-trifluoroethane
2,2,-Dibrorr*>-1,1,1 -trifluoroethane
2.3-Dibromo-1,1,1 -trifluoropropane
Bromodifuofomettiane
2-Bromo-1,1,1,2-tetrafluore thane
CHBr^
CBrF2CHBrF
CHBr2CF3
CF3CHBrCH2Br
CHBrF2
CFjCHBrF
yes
yes
yes
yes
yes
yes
no
no
no
no
yes
no
no
no
no
no
no
no
FLUOROIODOCARBONS
T rifkioroi odomethane
Difluoriodomethane
F luoroiodomethane
Pentafluoroiodoetha ne
Perfluoro-rv-propyl Iodide
Perfl uoroisopropyl iodide
Perfluoro-n-butyl iodide
Perfl uoro-n-hexyt iodide
Perfluoro-n-octyl Iodide
cf3i
chf2i
ch2fi
cf3cf2i
cf3cf2cf2i
cf3cficf3
CF3CF2CF2CF2I
CF3{CF2)4CF2l
CF3(CF2)6CF2l
no
no
no
no
no
no
no
no
no
no
no
no
no
yes
no
no
no
yes
no
no
no
no
no
no
no
no
no
HAIOETHERS
Perfluorodimethyl ether
Methyl trifluoromethyl ether
Difluoromethyl fluoromethyl ether
1,1,2,2-Tetrafluoro-dimethyl ether
Trifluoromethyl difluoromethyl ether
Trlfluoromethyl pentafluoroethyl ether
Perfluorooxetane
1,1,2,2,-Tetrafluoroethyl difluoromethyl ether
CF3OCF3
CH3OCF3
chf2och2 f
chf2ochf2
cf3ochf2
cf3ocf2chf2
-cf2cf2cf2o-
chf2 ocf2chf2
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
(continued)
-------
TABLE B-8. (concluded)
Name
Formula
Montreal Protocol and TSCA
Amendments (listed)
CAAA, RCRA, CERCLA, SARA,
OSHA, CWA, SDWA (all reflulated)
1,1,1-T rifliiofolsopropyl t rifluoromethyt ether
1,1,1 -T rifluoroethy) difluoromethyl ether
1,1 -Difluoroethyt fluoromethyt ether
Perfluorodi methoxymethane
Trifluoroethyl bromodifluoromethyl ether
Difluoromettiyl bromotetrafluoroethyl ether
Methyl bromodifluorornethyl ether
CH3(CH3)CHOCF3
cf3ch2ochf2
chf2ch2 och2f
CH3OCF2OCF3
CH3OCBrF2
CHF20CF2CBrF2
CH3OCF2Br
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
BROMOFLUOROALKENES
3-Bromo-3,3-difluoropropene
3-(BrorrKxjifluoromethyt)-3,4,4l4-tetrafluoro-1 -butene
2-Bromo-3,3,3-trifluoro-1 -propene
4-Bromo-3,3,4,4-tetrafluoro-1 -butene
2,3-Dibromo-3,3-difluoro-1-propene
4-Bromo-3-chloro-3,4,4-trifliioro-1 -propene
1,2-Dibfomo-3,3,3-trifIuoro-1 -propene
3-Bromo-1,1,3,3-tetrafluoro-1 -propene
1 -Bromo-3,3,3-trifluoro-t -propene
CH2=CHCBrF2
CH2=CHC(CBrF2)FCF3
CH2=CHBrCF3
CH2=CHCF2CBrF2
CH2=CBrCBrF2
CH2=CHCCIFCBrF2
BrCH=CBrCF3
CF2=CHCBrF2
BrCH»CHCF3
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
-------
APPENDIX C
LIST OF CHEMICAL SUPPLIERS
Dr. James Adcock
Department of Chemistry
575 Buchlcr Hall
University of Tennessee
Knoxville, Tennessee 37996-1600
Great Lakes Chemical Corporation
P.O. Box 2200
Highway 52 N.W.
W. Lafayette, IN 47906
(317) 497-6100
Aldrich Chemical Company, Inc.
P. O. 2060
Milwaukee, WI 53201
(800) 231-8327
(414) 273-3850
Allied-Signal, Inc
P.O. Box 2064R
Morristown, NJ 07960
(619) 235-9400
Lec Chambers
Elf Atochem North America, Inc.
Three Parkway
Philadelphia, PA 19102
(215) 587-7142
Crescent Chemical Co.
1324 Motor Parkway
Hauppauge, NY 11788
(516) 348-0333
FAX (516) 348-0913
E.I. DuPont de Nemours & Co.
Chemical & Pigments Dept., Freon Division
Nemours Bldg.
Wilmington, DE 19898
(800)441-7515
(800) 441-9442
Fluorochem Limited
Wesley Street, Old GIossop
Derbyshire, SKI3 9RY
England
FAX: (0457)869360
Flura Corporation
Rock Hill Laboratories
Route 4
Rock Hill Road
Newport. TN 37821
(615) 623-4111
K & K Laboratories
Division of ICN Biomedicals, Inc.
121 Express Street
Plainview, NY 11803
(800) 854-0530
(516) 433-6262
MG Industries
Gas Products Division
2460 Blvd. of the Generals
Valley Forge, PA 19482
(800) 345-6361
(215) 630-5492
PCR, Inc.
P. O. Box 1466
Gainesville, FL 32602
(904) 376-8246
FAX (904) 371-6246
Pfaltz & Bauer, Inc.
172 E. Aurora St.
Waterbury, CT 06708
(203) 574-0075
FAX (203)574-3181
Solkatronic Chemicals, Inc.
30 Two Bridges Road
Fairfield. NJ 07006
(201)882-7900
FAX: (201)882-7967
Union Carbide Industrial Gases. Inc.
Linde Division
200 Cottontail Ln
P.O. Box 6744
Somerset, NJ 08873
(201)271-2600
(201) 560-9799
95
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