Reducing Emissions of
PFC Heat Transfer Fluids
Phillip Tuma
3M Company, St. Paul, MN 55144
Lew Tousignant
3M Company, St. Paul, MN 55144
Abstract
Semiconductor manufacturing processes such as etch,
plasma vapor deposition (PVD), ion implant and test
require dielectric heat transfer liquids to maintain
process or component temperatures. Both deionized-
water-based liquids (DI water, DI water/glycol) and
Perfluorocarbon (PFC) liquids
[1] have traditionally
been used in these applications. In a growing percentage
of applications, PFCs are being used not only because
they possess the requisite safety, performance,
maintenance and dielectric properties but because they
can span the temperature range of the application.
In a Memorandum of Understanding (MOU) with the
EPA, various semiconductor manufacturers agreed to
reduce their emissions of specific PFC gases, most of
which are generated by plasma-aided processes. As
these emissions are reduced, the percentage of PFC
emissions attributable to PFC heat transfer
liquids is
growing. As soon as 2002, the global warming
contribution of liquid emissions could exceed those of
gaseous emissions in some facilities.
This paper discusses two different approaches for
reducing PFC heat transfer liquid emissions. The first
approach involves an on-site review of each system to
identify and eliminate likely leaks and evaporative loss
mechanisms. The second approach is the adoption of
alternative liquids. Many of the alternatives usable
beyond the temperature limitations of aqueous liquids
are also flammable, corrosive or regulated for their
toxicity. One class of alternatives, Segregated
Hydrofluoroethers (HFEs), has no such limitations.
These liquids have Global Warming Potentials (GWPs)
that are 0.5-5% those of common PFC liquids. Their use
requires little or no equipment modification the cost of
these materials is similar to and often lower than PFCs.
1. Introduction
1.1 Gaseous PFC Emissions
The global warming effect of gaseous PFC emissions
attributable to the semiconductor industry is generally
agreed to be <0.4% of that attributable to other
greenhouse gases.
[2] The industry has nevertheless
begun to voluntarily reduce its gaseous emissions of
perfluorocompounds which come predominantly from
the plasma processes etch and CVD. Its efforts were
first evidenced in the 1996 Memorandum of
Understanding (MOU) with the EPA.
[3] As part of this
agreement, several members of the Semiconductor
Industry Association (SIA) agreed to reduce their
emissions of greenhouse gases. In 1999 the WSC
(World Semiconductor Council) established an
international semiconductor industry goal to reduce
absolute emissions of global warming gases. In 2001,
the MOU was renewed with wider participation and
more specific emission reduction goals.
[4] Industry
efforts resulting from these agreements have included:
process optimization; abatement, capture and recycle
programs; and the adoption of alternative plasma
chemistries.
The industry’s gaseous emission reduction strategies
have been successful. Beu, et al [5] presented results of
three Tier 2 methods developed by the WSC to estimate
emissions of the MOU gases CF
4
, C
2
F
6
, CHF
3
, C
3
F
8
,
c-C
4
F
8
, NF
3
and SF
6
from etch and PVD/CVD
processes. These methods were applied to a typical,
high volume 200mm wafer manufacturing facility.
These data predict a strong downward trend between
1999 and 2002, a trend consistent with the goals of the
MOU and the WSC.
1
The term PFC, as it is used here, refers to a number of perfluorinated liquids including perfluoroalkanes, perfluoropolyethers and
perfluoroamines. These are sold under the tradenames Galden
™
and Fluorinert
™
.
2
Determined using radiative forcing data from D. Wuebbles, “The effects of Perfluorocompounds on the Global Environment,”
Presentation at the Global Semiconductor Industry Conference on Perfluorocompound Emissions Control, Monterey Ca, April 7-8, 1998.
3
E. Dutrow, “A successful year in the Partnership,” A Partnership for PFC Reduction, Semicon Southwest 97, Austin Convention Center,
Austin Texas, October 13, 1997.
4
Semiconductor Firms Sign New MOU to Slash PFC Emissions by 2010, Chemical Week, Volume 16(5), March 15, 2001.
5
L. Beu, J. Peterson and P. Brown, “Analysis of IPCC Emissions Estimating Methodology,” Partnership for PFC Emissions Reduction,
Semicon Southwest, Austin, Texas, 16 October, 2000.
As presented in the EHS Challenges and Analytical Methodologies session at the SEMI Technical Symposium:
Innovations in Semiconductor Manufacturing during SEMICON
®
West, July 16, 2001.
2
1.2 PFC Heat Transfer Fluid
Emissions
Perfluorocarbon (PFC) liquids were first used as heat
transfer media in the early 50s, primarily to cool
sensitive military electronics. PFC liquids were used
because they are chemically inert and non-flammable;
they have high dielectric strength and electrical
resistivity; and they evaporate cleanly. In the ’70s and
’80s these liquids debuted in the commercial sector
where they were used to perform thermal test and
reflow soldering operations and to cool
supercomputers, lasers, x-ray targets, etc. In the early
1990s, the semiconductor manufacturing industry
began using PFC liquids as heat transfer media to
control component temperatures in ion implanters, dry
etchers, deposition tools, steppers, automatic test
equipment (ATE) and other tools. Deionized aqueous
liquids (DI water and glycol) were being used in the
industry at that time but applications were emerging
that required the wider liquid range of PFCs. Today, as
operating temperature ranges continue to widen, the
functional limits of deionized liquids are being
challenged and PFCs are being used in an increasing
percentage of applications.
PFC liquids will evaporate when not contained. Given
the long atmospheric lifetime of the PFC vapors, the
vapors ultimately reach the upper atmosphere. Though
published atmospheric data for PFC liquids are
somewhat sparse, they indicate that PFC liquids have
atmospheric lifetimes and IR cross sections similar to
the PFC gases listed in the MOU. If the global warming
properties of a PFC material (or the vapor of that
liquid) have not been measured, it is standard practice
to substitute C
6
F
14
[6] data as a means of estimating the
environmental properties of that material. This practice
is generally sound, however, there are
perfluoropolyether liquids with GWPs as high as
11,500
[7] (the GWP of C
6
F
14
is 9,000 [8]).
On average, a typical high volume fab consumes 500
gallons of virgin PFC liquid during a year
[9] when no
manufacturing capacity is being added. Assuming
C
6
F
14
properties, this equates to 0.0079 million metric
tons of carbon equivalent (MMTCE) per fab per year.
As these fluids are rarely incinerated or recycled, a fab’s
fluid consumption equates roughly with what is emitted
to the atmosphere via equipment leaks, evaporation and
spills. Table 1 compares this PFC liquid emission to
total (gas + liquid) MMTCE emissions using MOU gas
emissions published by Beu.
These data show that even today emissions of PFC heat
transfer liquids are a significant percentage of a
facility’s MMTCE emissions.
2. Reducing PFC Liquid
Emissions
2.1 PFC Liquid Loss Prevention
A critical on-site review of a heat transfer system
installation can often reveal causes of fluid loss. Causes
of liquid leaks include inappropriate or damaged
connections, inappropriate valves or pumps and others.
An often overlooked mechanism is evaporative loss
resulting from temperature cycles.
[10] An
understanding of this mechanism can, in some
instances, reduce losses dramatically.
When effective, the loss reduction strategy will
immediately reduce liquid costs with a nominal
investment of time and little or no cost. It can also
reduce service time and prevent false Fluorine alarm
triggers, etc. However, the effectiveness varies widely.
On average, losses are reduced no more than 20%.
2.2 Alternative Liquids
The most effective strategy for reducing global
warming emissions resulting from PFC liquids is
replacement of these liquids with low-GWP
alternatives. While a variety of alternatives can satisfy
the temperature requirements of semiconductor
applications, many suffer limitations that make their
use impractical.
[11] For example, petroleum-based
products, silicone oils and citrus-based oils tend to be
flammable or unstable. Chlorofluorocarbons are ozone
depleting and other chlorinated materials like
dichloroethylene, trichloroethylene and methylene
chloride are either flammable, unstable or highly
regulated.
6
In lieu of accurate environmental data for PFCs of higher boiling point, the US EPA recommends use of perfluorohexane data (Inventory
of US Greenhouse Gas Emissions and Sinks: 1990-1996, US EPA Doc EPA236-R-98-006, 1998).
7
3M Technical Report, J. G. Owens and L. Tousignant, “Measured IR Cross-Sections and GWPs for FC-3283 and HT-135,” June 2001.
8
Based on an integration of the radiative forcing effect over a 100 year period or integrated time horizon (ITH). Scientific Assessment of
Ozone Depletion: 1998, WMO Global Ozone Monitoring Project, Report No. 44.
9
Based on 3M market studies.
10
Tuma, P.E. and Tousignant, L., Modeling Vapor Leak Rate and System Pressures for Single Phase Heat Transfer Systems that Utilize
Fluorinated Heat Transfer Liquids, To be published.
11
Tuma, P.E., “Segregated Hydrofluoroethers: Long Term Alternative Heat Transfer Liquids,” Proceedings of the 2000 Earth Technologies
Forum, Oct.30-Nov.1, Washington D.C., pp. 266-275.
3
2.3 Utility of Segregated
Hydrofluoroether (HFE) Heat
Transfer Liquids
Though a variety of HFEs have been synthesized, their
performance and environmental properties and hence
their utility can vary widely.
[12] Research has shown
that segregated HFE liquids, as a class, have a desirable
balance of properties. The term “segregated” refers to
HFEs that possess a perfluorocarbon segment separated
or “segregated” from a fully hydrocarbon segment by
an ether oxygen. Examples include the structures
shown in Table I and discussed in this work
[13]:
C
3
F
7
OCH
3
, C
4
F
9
OCH
3
, C
4
F
9
OC
2
H
5
and
C
3
F
7
CF(OC
2
H
5
)CF(CF
3
)
2
. These liquids possess a
balance of properties that makes them well suited for
semiconductor heat transfer applications.
2.3.1 Environmental Properties
Like PFCs, the aforementioned HFEs are non-ozone
depleting. Because they are not photolyzed in the lower
atmosphere where breakdown products would
contribute to atmospheric smog formation, the US EPA
and most state agencies have exempted C
4
F
9
OCH
3
and
C
4
F
9
OC
2
H
5
from the definition of a volatile organic
compound (VOC). As the relevant properties of
C
3
F
7
OCH
3
and C
3
F
7
CF(OC
2
H
5
)CF(CF
3
)
2
are similar,
they too are expected to receive this exemption.
In the troposphere, reactive hydroxyl radicals quickly
break down these HFE molecules, resulting in short
atmospheric lifetimes and GWPs that are 0.6-5% that
of C6F14. The GWPs and atmospheric lifetimes of the
segregated hydrofluoroethers, as a class, are
significantly lower than the hydrofluoropolyethers
(HFPEs) described by Marchionni.
[14] This is shown
in Figure 1. The segregated HFE chemistry has been
commended for this quality
[15] through numerous
environmental awards.
[16,17,18,19]
2.3.2 Useful Temperature Range
The temperature range of the segregated HFEs is
shown in Figure 2 along with DI water and a 50%
ethylene glycol solution. The lower limit for HFEs and
for DI glycol is defined here as the temperature at
which the viscosity reaches 30 centiStokes (cSt). There
are two upper temperature limits shown for the HFEs.
The first of these, which is shown in white, is the
boiling point of the fluid. This is the practical limit for
semiconductor systems which tend to operate at low or
ambient pressure. The second limit, which is shown in
grey, is the thermal stability limit. It is more relevant for
high pressure systems. The upper limit for DI fluids is
dependent upon the desired resistivity which, in turn,
dictates the corrosiveness of the fluid. For example, DI
water with resistivity of 10 Mohm-cm will function
well in stainless steel at 25°C but may cause corrosion
at 60°C. DI liquids cannot generally be used above
80°C.
The Semiconductor Industry’s transition from PFC
liquids to HFEs has been limited primarily by the
boiling points of commercially available segregated
HFEs. C
4
F
9
OCH
3
(boiling point 61°C) has been
available commercially since 1996 and has been used in
Automatic Test Equipment (ATE) since 1997. Before
2000, the highest boiling point HFE, C
4
F
9
OC
2
H
5
, had
a boiling point of 76°C and could not be used above
about 70°C. This limitation prevented use of HFE
liquids in what have typically been higher temperature
applications like etch and PVD.
C
3
F
7
CF(OC
2
H
5
)CF(CF
3
)
2
became commercially
available in 2000. Its 130°C boiling point and low
temperature properties allow it to span the bulk of
applications in the industry. This fluid has already been
qualified by major etch and CVD manufacturers and is
now an option on some equipment platforms. HFEs
that meet the requirements of higher temperature
applications like thermal shock (i.e. Military Standard
883) are under development.
12
Bivens, D.B., and Minor, B.H., “Fluoroethers and other Next-Generation Fluids,” ASHRAE/NIST Refrigerants Conference, October
1997, pp. 122-134.
13
C
4
F
9
OCH
3
, C
4
F
9
OC
2
H
5
and C
7
F
15
O
2
H
5
sold commercially as 3M
™
Novec
™
Engineered Fluid HFE-7100, HFE-7200 and HFE-7500,
respectively. C
3
F
7
OCH
3
is currently under development by 3M.
14
G. Marchionni, et al, “Hydrofluoropolyethers,” Journal of Fluorine Chemistry, 95, 1999, pp. 41-50.
15
Correspondence with Anhar Karimjee, SNAP Team Leader, Global Programs Division, US EPA, January 2001.
16
1997 American Chemical Society “Heroes of Chemistry Award” in the category of Chemistry and the Environment for development of
segregated hydrofluoroethers as alternatives to ozone-depleting materials.
17
In April 1999 C
4
F
9
OC
2
H
5
was designated a “Clean air Solvent” by the South Coast Air Quality Management District.
18
C
4
F
9
OCH
3
and C
4
F
9
OC
2
H
5
are approved for “use without restriction” under the US EPA’s Significant New Alternatives Program
(SNAP) which regulates the use of new materials in such chlorofluorocarbon (CFC) replacement applications as solvent, refrigeration,
heat transfer, and others.
19
The United Nations Environment Programme (UNEP) Technology and Economic Assessment Panel has recognized HFEs as meaningful
low-GWP replacements for ozone depleting substances, HFCs and PFCs.
4
For the extreme low temperature requirements that are
emerging in some copper PVD and test applications,
C
3
F
7
OCH
3
is available and has been used to -116°C.
Many PFC liquids are distillation fractions which are
composed of a variety of molecules of differing
molecular weight. When such a fluid is lost from a
system by evaporation the average molecular weight of
the remaining fluid rises resulting in higher viscosity
and reduced low temperature performance. This is not
true of the segregated HFEs discussed in this work.
2.3.3 System Compatibility
While many of the industry’s strategies for reducing
gaseous PFC emissions are relatively straightforward,
others have required significant development effort and
capital investment. In contrast, the conversion of a well-
designed PFC heat transfer system to operate with
HFEs often requires no retrofit at all. To determine
whether an HFE can be “dropped into” an existing PFC
system, the following must be reviewed:
1) Like PFC liquids, segregated HFEs are inert to
common metals and hard polymers
[20] and are even
being used in direct contact cooling of electronics.
HFEs do, however, have some solvency for many of
the additives and plasticizers commonly added to
elastomers. Heavily plasticized elastomers may
shrink or become brittle while relatively pure
elastomeric polymers perform well. For this reason,
no sweeping statements can be made about the
compatibility of the various types. Attention must be
paid to the particular formulation.
a) O-rings and seals should be made of
Fluoroelastomers previously used successfully in a
PFC system or hydrocarbon-based elastomers (i.e.
butyl, nitrile, EPDM, silicone, etc.) specifically
tested or otherwise known to be low in extractable
material. 3M maintains databases of compatible
materials and also provide free testing services.
b) TFE, PFA or thermoplastic hoses that have been
used in PFC systems generally perform well with
HFEs. Elastomeric or “rubbery” tubing/hoses
should be low in extractable material.
HFE fluids can generally be dropped into existing
systems that conform to the criteria mentioned above
provided the HFE’s electrical properties are adequate.
2.3.4 Electrical Properties
At ~40 kV for a 0.1 inch gap, the dielectric strength of
the segregated HFEs is similar to that of a PFC. The
electrical resistivity of these HFEs is typically 108
ohm-cm while PFC liquids are typically 1015ohm-cm.
This reduction is the result of hydrogen present on the
HFE molecules and, as such, is a natural consequence
of their reduced GWP. The reduced resistivity of HFEs
is very rarely an issue as DI water, whose resistivity
rarely exceeds 107ohm-cm, is commonly used when its
other properties permit. The dielectric constant of a
PFC liquid is usually less than 2 while HFE liquids
have dielectric constants as high as 8. Lastly, because
HFEs absorb in the microwave potion of the
electromagnetic spectrum, they are not suited for
cooling in some plasma generation applications.
2.3.5 Performance
The physical properties of HFE fluids are generally
superior to PFC fluids of similar boiling point. This is
shown in Table 2. HFEs generally have slightly higher
specific heat and lower viscosity and density than PFCs
of similar boiling point. These characteristics are
advantageous in most heat transfer applications as they
bring about reduced pumping power, better heat
transfer performance and a wider useful temperature
range. The utility of HFEs has been demonstrated in a
variety of applications.
[21,22]
2.3.6 Stability
When used below their boiling point, the HFE fluids
shown in Figure 1, like PFCs, should not require
replacement. Their operational lifetimes above the
boiling point and below the thermal stability limit (grey
region in Figure 2) depend largely upon the amount of
time spent at that temperature and the amount of water
present. A lifetime of many years is expected if the
system is kept dry.
In some applications, it is possible to exceed the
limitations indicated in Figure 1. Often the pump is
turned off while a relatively brief high temperature
operation is performed on some sub-portion of the
system. An example is a PVD system in which the
chuck is periodically “baked out” to remove residue
that accumulates during processing. If the system is
plumbed properly, it is possible to maintain only a small
amount of superheated HFE vapor within the chuck
during this operation.
20
Tuma, P.E., “Using Segregated HFEs as Heat Transfer Fluids - Avoiding problems in system design,” Chemical Processing,
February 2001, pp. 47-50.
21
Tuma, P.E., “Hydrofluoroethers as Low-Temperature Heat-Transfer Liquids in the Pharmaceutical Industry,” Pharmaceutical
Technology
, March 2000, pp.104-116.
22
Tuma, P.E. and Tousignant, L., “New “Green” Heat Transfer Liquids,” Solid State Technology, June 2000, pp.175-182.
5
Not only is the amount of fluid represented by this
vapor a small percentage of the overall system charge,
but the kinetics of thermal decomposition are different
in this vapor than in liquid heated under pressure to the
same temperature. It has been shown experimentally,
for example, that C
4
F
9
OCH
3
can be used in some PVD
applications safely and without corrosion even at a
bakeout temperature of 275°C.
[23]
2.3.7 Safety and Health
Because heat transfer systems are contained, worker
exposure to HFE fluids once they’re installed in a
system are exceedingly low. Significant exposures are
limited to filling and draining operations. Industrial
hygiene experiments have been conducted with
C
4
F
9
OCH
3
and C
3
F
7
CF(OC
2
H
5
)CF(CF
3
)
2
for typical
filling scenarios including 10 ft
2
spills. Worker
exposures, as measured by FTIR, show acute exposures
well below the guideline for an 8-hour work day.
[24]
These materials are both very low in acute toxicity.
Table 2 summarizes toxicological data for C
4
F
9
OCH
3
and C
4
F
9
OC
2
H
5
. The American Industrial Hygiene
Association (AIHA) has set an 8-hour worker exposure
guideline of 750 parts per million (ppm) for C
4
F
9
OCH
3
based on the results of a 90-day inhalation study. This
material is not a cardiac sensitizer at >100,000 ppm and
is non irritating to the skin and eyes.
Toxicity tests conducted by Sekiya and Misaki
[25]
with C
3
F
7
OCH
3
resulted in an acute oral LD
50
of
>2000 mg/kg. Inhalation tests conducted 6 hours per
day for 7 days showed a NOEL of >7.0 g/m
3
(850
ppmv). The compound tested negative in the Ames
mutagenicity test and was not a skin irritant. 3M has
corroborated that C
3
F
7
OCH
3
is low in both acute and
sub-acute toxicity. A 28-day inhalation study was
conducted at 1000, 10,000 and 30,000 ppm. The No
Adverse Effect Level (NOAEL) in this study was 1000
ppm. This data suggests there is a large margin of safety
for use of this HFE in relatively non-emissive heat
transfer systems.
Toxicity tests conducted to date with
C
3
F
7
CF(OC
2
H
5
)CF(CF
3
)
2
indicate this compound
exhibits a very low order of toxicity. For instance, the
acute oral LD
50
for this compound is greater than 2000
mg/kg. C
3
F
7
CF(OC
2
H
5
)CF(CF
3
)
2
is not classified as
either an eye or skin irritant. The molecule tested
negative in two mutagenicity screens, the Ames assay
and the chromosomal aberration assay. In a 28-day
feeding study, no adverse health effects were observed
at a dosing level of 1000 mg/kg body weight.
None of the HFEs described herein has an open-cup or
closed-cup flash point. They are therefore assigned
NFPA (National Fire Protection Association)
flammability indices of zero.
For all of these reasons, these four materials are not
regulated for transport nor are they considered
hazardous air pollutants.
3. Conclusions
• A fab’s PFC heat transfer liquid emissions are a
significant and growing portion of its total PFC
emissions.
• Use of commercially available segregated HFE liquids
can reduce global warming emissions attributable to
PFC liquids by 95% to over 99.5%.
• The performance properties of these segregated HFEs
are generally superior to existing PFC liquids. The
electrical properties are an exception and may
preclude HFE use in some applications.
• Conversion of a PFC system to operate with a
segregated HFE is often a “drop-in” procedure or may
simply require an O-ring or hose replacement.
• These segregated HFEs are nonflammable; they have
favorable toxicological properties; they are not
regulated for transport or use; and they cost about the
same as PFCs.
23
P. T uma and L. Tousignant, Experimental Study of the Decomposition of HFE-7100 Vapor in a Billet of TI-6AL-4V During Bakeout at
275°C, 3M internal report, August 2000.
24
T. Gutzkow, Comprehensive Industrial Hygiene Test Report, 3M Internal report, Lab request EL1184, February 14, 2000.
25
A. Sekiya and S. Misaki, “The potential of hydrofluoroethers to replace CFCs, HCFCs and PFCs,” Journal of Fluorine Chemistry,
101, 2000, pp. 215-221.
6
Figure 1
GWPs (100-year ITH) of segregated HFEs compared to other HFEs and to PFCs.
Table 1
Compares PFC liquid emissions to total (gas + liquid) MMTCE emissions using
MOU gas emissions published by Beu.
Figure 2
Operating Temperature of Segregated HFE Liquids
0 5000 10000 15000 20000
PFCs
All HFEs
HFEs from [14]
HFEs of this Work
GWP (100 year ITH)
-150 -100 -50 0 50 100 150 200 250
C
3
F
7
OCH
3
C
4
F
9
OCH
3
C
4
F
9
OC
2
H
5
C
7
F
15
OC
2
H
5
Under Development
DI Glycol
DI Water
Temperature [°C]
Liquid Range
Stability Limit
Total MMTCE PFC liquid %
Gaseous of Total
1999 Tier 2a 0.03904 16.8
1999 Tier 2b 0.03401 18.8
1999 Tier 2c 0.03468 18.5
2002 Tier 2a 0.00642 55.2
2002 Tier 2b 0.01105 41.7
2002 Tier 2c 0.00756 51.1
7
Property HFE Fluorinert HFE Fluorinert HFE Galden HFE Fluorinert Galden
HFE-7000
1
FC-87
1
HFE-7100
1
FC-72
1
HFE-7200
1
HT-70
2
HFE-7500
1
FC-3283
1
HT-135
2
C
3
F
7
OCH
3
C
4
F
9
OCH
3
C
4
F
9
OC
2
H
5
C
7
F
15
OC
2
H
5
Atmospheric 4.7 4100 4.1 3200 0.8 3200 2.5 2000 N/A
Lifetime [yrs]
GWP (100 year ITH) 400 8900 320 9000 55 9000
3
210 8600 N/A
Boiling Point [°C] 34 30 61 56 76 70 128 128 135
Pour Point [°C] -122.5 -115 -138 -90 -135 <-110 -100 -50 <-100
Useful low -122.5 -115 -106 -90 -106 -93 -75 -50 -67
Temperature [°C]
4
Density [kg/m3] 1400 1650 1420 1680 1510 1680 1614 1820 1730
Coefficient of 0.00219 0.0015 0.0016 0.0016 0.0018 0.0011 0.00129 0.0014 0.0011
Expansion [1/°C]
Specific Heat [J/kg-K] 1300 1100 1220 1100 1180 960 1128 1050 960
Thermal Conductitivty 0.075 0.056 0.068 0.057 0.069 0.07 0.065 0.066 0.07
[W/m-K]
Viscosity [cSt] at 25°C 0.32 0.28 0.37 0.38 0.44 0.5 0.77 0.75 1.00
at -40°C 0.78 0.76 1.1 1.17 1.26 1.79 3.55 4.26 6.33
Dielectric Strength ~40 ~40 ~40 ~40 ~40 40 ~40 ~40 40
[kV, 0.1 inch gap]
Dielectric Constant 7.4 1.7 7.3 1.75 7.4 2.1 5.8 NA 2.1
Electrical Resistivity 1.E+08 1.E+15 1.E+08 1.E+15 1.E+08 1.E+15 1.E+08 1.E+15 1.E+15
[ohm-cm]
Medium TemperatureLow Temperature
N/A = Not available
1
Properties for Fluorinert
™
and Novec
™
materials were taken from 3M Product Literature.
2
Properties for Galden HT-70 and HT-135 were taken from Ausimont product literature “Galden
®
Heat Transfer Fluids.”
3
The US EPA recommends the use of C
6
F
14
data for perfluorocarbons where measured data are not available (Inventory of US
Greenhouse Gas Emissions and Sinks: 1990-1996, US EPA Doc EPA236-R-98-006, 1998).
4
The useful low temperature was defined as the higher of the freezing temperature and the temperature at which the fluid kinematic
viscosity reached 30 cSt.
Table 2
Physical Properties of segregated HFEs compared to common PFCs.
Table 3
Toxicological data for C
4
F
9
OCH
3
and C
4
F
9
OC
2
H
5
.
C
4
F
9
OCH
3
C
4
F
9
OC
2
H
5
Acute Lethal Conc., 4 hr > 100,000 >92,000
LC50, ppmv
Oral Toxicity Practically non-toxic (>5 g/kg) Practically non-toxic (>5 g/kg)
Mutagenicity Negative Negative
Cardiac Sensitization >100,000 >20,000
Threshold, ppmv
Ocular Irritant No Mimimally Irritating
Dermal Irritant No No
Exposure Guideline 750 200
8 hr TWA, ppmv
Exposure Ceiling, ppmv None None
4211 (HB)
© 2002 3M 98-0212-2591-1
Issued: 3/02
Specialty Materials
3M Center, Building 223-6S-04
St. Paul, MN 55144-1000
www.3m.com/fluids
3
Important Notice to Purchaser: The information in this publication is based on tests that we believe are reliable.Your results may vary due to
differences in test types and conditions.You must evaluate and determine whether the product is suitable for your intended application. Since
conditions of product use are outside of our control and vary widely, the following is made in lieu of all express or implied warranties (including
the warranties of merchantability or fitness for a particular purpose): 3M’s only obligation and your only remedy is replacement of product that
is shown to be defective when you receive it. In no case will 3M be liable for any special, incidental, or consequential damages based on
breach of warranty or contract, negligence, strict tort, or any other theory.
