United States
Environmental Protection
Agency
Environmental Criteria and
Assessment Office
Research Triangle Park NC 27711
Research and Development
EPA-600/S8-82-002F Dec. 1983
Project Summary
Health Assessment
Document for 1,1,2-Trichloro-
1,2,2-Trif luoroethane
(Chlorofluorocarbon CFC-113)-
Final Report
Richard Carchman and Mark M. Greenberg
The Office of Health and Environmen-
tal Assessment has prepared this health
assessment to serve as a source docu-
ment for EPA use. Originally the health
assessment was developed for use by
the Office of Air Quality Planning and
Standards to support decision-making
regarding possible regulation to chloro-
fluorocarbon 113 (CFC-113} as a ha-
zardous air pollutant. However, at the
request of The Agency's Work Group on
Solvents the assessment scope was ex-
panded to address multimedia aspects.
In the development of the assessment
document, the scientific literature has
been inventoried, key studies have been
evaluated, and summary/conclusions
have been prepared so that the toxicology
of CFC-113 and the chemical's related
characteristics are qualitatively identi-
fied. Observed-effect levels and dose-
response relationships are discussed,
where appropriate, so that the nature of
the adverse health responses are placed
in perspective with observed environ-
mental levels.
This document evaluates health
effects associated with exposure to
CFC-113. CFC-113 is released into the
environmental air as a result of evapora-
tive loss during production storage,
consumer use, and manufacturing use.
In regard to potential health effects
associated with CFC-113, there is no
evidence indicating that human health
effects are likely to occur at ambient air
mixing ratios (e.g., 18 ppt; 0.14 x 10~3
mg/m3) found or expected in the general
environment or even at higher levels
«4. 160 ppt; <0.032 mg/m3) some-
times observed in urban areas. In fact,
available experimental data do not
indicate that any adverse health effects
are directly induced in humans at TLV®
of 1,000 ppm (7,700 mg/m3) due to
exposure to CFC-113. The health
information pertaining to CFC-113 is
discussed in detail. This document also
discusses production, use, sources,
emissions and ambient levels so that
CFC-113 is placed in a real-world
perspective.
This Project Summary was developed
by EPA's Environmental Criteria and
Assessment Office. Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title fsee Project Report ordering
information at back).
Introduction
The principal intent of this document is
to evaluate health effects associated with
exposure to CFC-113. The nature of the
known health effects primarily involves
impairment of neurological and cognitive
functions (humans) and cardiovascular
system (animals) following acute exposure
to levels greatly exceeding 1,000 ppm
(7,700 mg/m3). The health information
pertaining to CFC-113 is discussed in
detail. In addition to evaluating the
spectrum of health effects associated
with CFC-113 release to the environment,
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this document also discusses analytical
methods, production, sources, emissions,
and ambient levels to place CFC-113 in a
real-world perspective.
Chemical and Physical Properties
Chlorofluorocarbons, in general, are
characterized by high density, low boiling
point, low viscosity, low surface tension,
and high thermal andphotostability They
do not react with most metals below
200°C nor do they generally react with
acids or oxidizing agents. However,
specific and unusual applications should
be carefully reviewed and tested.
Trichlofotrifluoroethane (CFC-113) is a
nonflammable, colorless liquid, character-
ized by a moderately high vapor pressure
and a low boiling point (Table 1) and by
high thermal and photostability. It is
practically insoluble in water and is
extremely resistant to hydrolysis. At
equilibrium with a partial pressure of one
atmosphere and at 86°F, less than 0.005
grams of CFC-113 per liter of water per
year are hydrolyzed.
Table 1. Physical Properties of CFC-113
Molecular weight
Boiling point
Vapor pressure
Density
Solubility
187.4
47.6°C (760 mm)
6.5 Ib/in* (25°C)
1.5 gm/cm3
0.017gm/100gmH2O
(25°C. 760 mm)
Air Quality Considerations
Environmental Sources and
Emissions
Principal uses of CFC-113 fall into
several mam categories (1) degreasmg,
cleaning, and drying applications, (2)
removal of solder flux, (3) critical cleaning
of electronic, electrical and mechanical
assemblies, (4) application as a cutting
fluid, carrier and reaction medium, and
(5) as a dry cleaning solvent. It is not used
in aerosol formulations as a propellant or
as a propellant component, but is used as
a solvent or active ingredient in certain
aerosol formulations.
In cleaning and drying operations, two
types of solvent losses occur: (1) escape
in vapor form and (2) in liquid form when
tanks are emptied for cleaning. Although
there are not identified reports that CFC-
113 has been detected in drinking or
surface waters, this potential exists since
CFC 113 may be sealed in drums and
buried Because CFC-113 has very
limited solubility m water and is highly
volatile, all releases of CFC-113 can be
expected to eventually be conveyed to the
atmosphere. The World Meteorological-
Organization, citing figures supplied by
E.I. duPont de Nemours and Company,
reported a current global annual emissions
rate of about 91,000 metric tons.
Levels and Atmospheric Fate
The World Meteorological Organization
reported that ambient air levels are iathe
range of 12 to 25 ppt in the northern
hemisphere and 11 to 22 ppt in the
southern hemisphere. Based on measure-
ments made at sites in the United States,
CFC-113 background tevelsare generally
less than 20 ppt. Higher levels (—4,000
ppt) have occasionally been observed, ip,
urban areas. • '
Because it is essentially inert in the
troposphere, CFC-113 is transported
slowly to the stratosphere. While CFC-113
has some potential to perturb stratospheric
ozone, there is presently no evidence
demonstrating that any indirect effects of
CFC-113 on human health has or is likely
to occur as a result of ozone perturbation.
Because ozone effectively absorbs ultravio-
let-B radiation, an actual decrease in
stratospheric ozone concentration is
expected to result in an increased amount
of this biologically-damaging radiation
(incident at the earth's surface).
Human and Animal Studies
Effects on Humans
In regard to potential health effects
associated with CFC-113, there is no
evidence indicating that human health
effects are likely to occur to ambient air
mixing ratios (e.g., 18 ppt; 0.14 x 10~3
mg/m3) found or expected in the general
environment or even at higher levels
(<4,160 ppt; <0.032 mg/m3) sometimes
observed m urban areas. In fact, available
experimental data do not indicate that
any adverse health effects are directly
induced in humans at a TLAM' of 1,000
(7,700 mg/m3) due to exposure to CFC-
113.
Human exposure to CFC-113 is predom-
inantly by inhalation and most of it is
rapidly cleared from the body by exhalation.
Animal exposure studies indicate that
CFC-113 partitions preferentially into
lipid-rich tissues and is poorly metabolized.
Loss of CFC-113 from all tissues is rapid
during post-exposure periods, with
virtually 100 percent clearance within 24
hours after cessation of acute exposure.
At exposure levels greatly exceeding
1,000ppm (7,700 mg/m3), impairment of
neurological and cognitive functions has
been observed following acute exposure
to CFC-113. However, because of the lack
of detailed studies in this health area, a
conclusive assessment of the human
health risks posed by levels of CFC-113 in
the range 1,500 to 2,000 ppm (7,700 to
15,400 mg/m3) cannot be made. Also,
before definitive conclusions concerning
the effects of chronic long-term exposure
to CFC-113 can be drawn, the results of a
recently completed two-year chronic
inhalation study in rats must be evaluated.
Animal Studies
Various animal studies (non-human
primates and dogs) have indicated that
acute exposure to high concentrations of
CFC-113 (as low as 2,000 ppm or 15,400
mg/m3 in a 6-hour exposure period)
followed by a large injected dose of
epinephrine resulted in cardiac arrhyth-
mias. Concentrations as high as 20,000
ppm (154,000 mg/m3), however, did not
sensitize a dog's heart to the dog's own
circulating level of epinephrine even
when it was elevated by exercise.
Preliminary data from an industry-
sponsored, two-year chronic inhalation
study in rats indicate no hepatotoxic
effects attributable to CFC-113 at doses
as high as 20,000 ppm (154,000 mg/m3).
Histopathology is in progress.
There is presently inadequate published
information to assess carcinogenic
potential of CFC-113. Preliminary results
of a recently-completed one-generation
teratogenicity/reproductive toxicity study
in pregnant rats suggest that at the
exposure levels tested (5,000, 12,500,
and 25,000 ppm), there was no evidence
of teratogenic or embryotoxic effects
attributable to CFC-113.
Health Effects Conclusions
There is no evidence indicating adverse
health effects are likely to occur upor
exposure to CFC-113 levels found 01
expected in the general information
While there is inadequate published date
to assess the teratogenic and carcinogenic
potentials of CFC-113, preliminary result!
of recently-completed, long-term inhala
tion studies in rodents are consisten
with no adverse effects attributable t<
CFC-113 at levels up to 25,000 ppm
Further testing would be needed befor
definitive conclusions about the mutageni
potential of CFC-113 could be drawn.
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Richard C arch man is with the Virginia Commonwealth University, and the EPA
author, Mark M. Greenberg (also the EPA Project Officer, see below), is with
the Environmental Criteria and Assessment Office, Research Triangle Park, NC
27711.
The complete report, entitled "Health Assessment Document for 1,1,2- Trichloro-
1.2,2-Trifluoroethane (Chlorofluorocarbon CFC-113)—Final Report," (Order
No. PB 84-118 843; Cost: $11.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Criteria and Assessment Office
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
i>US GOVERNMENT PRINTING OFFICE 1984-759-015/7257
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