Disclaimer: These guidelines were developed under contract using generally accepted secondary sources. The protocol used by the contractor for surveying these data sources was developed by the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA), and the Department of Energy (DOE). The information contained in these guidelines is intended for reference purposes only. None of the agencies have conducted a comprehensive check of the information and data contained in these sources. It provides a summary of information about chemicals that workers may be exposed to in their workplaces. The secondary sources used for supplements 111 and 1V were published before 1992 and 1993, respectively, and for the remainder of the guidelines the secondary sources used were published before September 1996. This information may be superseded by new developments in the field of industrial hygiene. Therefore readers are advised to determine whether new information is available.
OCCUPATIONAL SAFETY AND HEALTH GUIDELINE FOR DICHLOROTETRAFLUOROETHANE
(REFRIGERANT 114)
INTRODUCTION
This guideline summarizes pertinent information about
dichlorotetrafluoroethane for workers and employers as well as for
physicians, industrial hygienists, and other occupational safety and health
professionals who may need such information to conduct effective occupational
safety and health programs. Recommendations may be superseded by new
developments in these fields; readers are therefore advised to regard these
recommendations as general guidelines and to determine whether new
information is available.
SUBSTANCE IDENTIFICATION
* Formula
C(2)Cl(2)F(4)
* Structure
ClF(2)C-CClF(2)
* Synonyms
Fluorocarbon 114, 1,2-dichlorotetrafluoroethane, freon 114,
refrigerant 114, halon 242, cryofluorane, FC-114
* Identifiers
1. CAS No.: 76-14-2
2. RTECS No.: KI1101000
3. DOT UN: 1958 12
4. DOT label: Nonflammable Gas
* Appearance and odor
Dichlorotetrafluoroethane is a gas with a sweetish, chloroform-like
odor; when pressurized or kept cold, it is a colorless liquid.
CHEMICAL AND PHYSICAL PROPERTIES
* Physical data
1. Molecular weight: 170.9
2. Boiling point (at 760 mm Hg): 3.5 degrees C (38.4 degrees F)
3. Specific gravity (water = 1): 1.5 at 0 degrees C (32 degrees F)
4. Vapor density: 5.9
5. Melting point: -94 degrees C (-137 degrees F)
6. Vapor pressure at 20 degrees C (68 degrees F): 1444 mm Hg
7. Solubility: Dichlorotetrafluoroethane is practically insoluble in
water at 20 degrees C (68 degrees F) but is soluble in alcohol and ether.
8. Evaporation rate: Data not available.
* Reactivity
1. Conditions contributing to instability: Heat.
2. Incompatibilities: Contact between dichlorotetrafluoroethane and
alkalies or alkaline earth metals such as sodium or potassium with calcium,
zinc, magnesium, or powdered aluminum should be avoided.
3. Hazardous decomposition products: Toxic gases and vapors such as
hydrogen chloride, phosgene, hydrogen fluoride, and carbonyl fluoride may be
released in a fire involving dichlorotetrafluoroethane.
4. Special precautions: None reported.
* Flammability
Dichlorotetrafluoroethane is a nonflammable gas at room temperature.
The National Fire Protection Association has not assigned a
flammability rating to dichlorotetrafluoroethane. Other sources rate
dichlorotetrafluoroethane as a minimal fire hazard when this substance is
exposed to heat or open flame.
1. Flash point: Not applicable.
2. Autoignition temperature: Not applicable.
3. Flammable limits in air: Not applicable.
4. Extinguishant: Use extinguishant suitable for materials in surrounding
fire. For small fires use dry chemical or carbon dioxide. Use water spray,
fog, or regular foam to fight large fires.
Fires involving dichlorotetrafluoroethane should be fought upwind
from the maximum distance possible. Keep unnecessary people away; isolate
the hazard area and deny entry. Isolate the area for 1/2 mile in all
directions if a tank, rail car, or tank truck is involved in the fire.
Emergency personnel should stay out of low areas. Cylinders of
dichlorotetrafluoroethane may explode in the heat of the fire and should be
moved from the fire area if it is possible to do so safely. If this is not
possible, cool fire exposed containers from the sides with water until well
after the fire is out. Stay away from the ends of containers. Personnel
should withdraw immediately if a rising sound from a venting safety device is
heard or if there is discoloration of a container due to fire. Firefighters
should wear a full set of protective clothing and self-contained breathing
apparatus when fighting fires involving dichlorotetrafluoroethane.
EXPOSURE LIMITS
The current Occupational Safety and Health Administration (OSHA) permissible
exposure limit (PEL) for dichlorotetrafluoroethane is 1000 parts per million
(ppm) parts of air (7000 milligrams per cubic meter (mg/m(3))) as an 8-hour
time-weighted average (TWA) concentration [29 CFR 1910.1000, Table Z-1].
* NIOSH REL
The National Institute for Occupational Safety and Health (NIOSH)
has established a recommended exposure limit (REL) for
dichlorotetrafluoroethane of 1000 ppm (7000 mg/m(3)) as a TWA for up to a
10-hour workday and a 40-hour workweek [NIOSH 1992].
* ACGIH TLV
The American Conference of Governmental Industrial Hygienists
(ACGIH) has assigned dichlorotetrafluoroethane a threshold limit value (TLV)
of 1000 ppm (6990 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour
workweek [ACGIH 1994, p. 19].
* Rationale for Limits
The NIOSH limit is based on the risk of respiratory irritation,
asphyxia at high concentrations [NIOSH 1992].
The ACGIH limit is based on the risk of systemic toxicity and
cardiac sensitization [ACGIH 1991, p. 444].
HEALTH HAZARD INFORMATION
* Routes of Exposure Exposure to dichlorotetrafluoroethane can occur
through inhalation, ingestion, and eye or skin contact [Sittig 1991].
* Summary of toxicology
1. Effects on Animals: dichlorotetrafluoroethane is a cardiac sensitizer,
an asphyxiant, and a weak narcotic at extremely high concentrations [ACGIH
1991]. Dogs exposed to 200,000 ppm of dichlorotetrafluoroethane for 16 hours
died, but exposures at this level for 8 hours caused tremor and convulsions
[Hathaway et al. 1991]. Serious arrhythmia occurred in one of 12 dogs
exposed once to 25,000 ppm of dichlorotetrafluoroethane and given intravenous
epinephrine. Dichlorotetrafluoroethane is reported to reduce pulmonary
compliance and act as a bronchoconstrictor [ACGIH 1991]. Guinea pigs exposed
to a dichlorotetrafluoroethane concentration of 47,000 ppm developed
respiratory irritation [Hathaway et al. 1991]. Repeated exposure to sprayed
dichlorotetrafluoroethane caused localized skin inflammation in rats and
irritation of the eyes of rabbits [ACGIH 1991].
2. Effects on Humans: Dichlorotetrafluoroethane is an asphyxiant at
extremely high concentrations and also produces narcotic symptoms at these
levels. The cardiac sensitization potential of dichlorotetrafluoroethane is
considered moderate; sniffing aerosols of other fluorochlorinated
hydrocarbons has caused cardiac arrest, although dichlorotetrafluoroethane
has not specifically been implicated in such deaths [Hathaway et al. 1991].
Contact of the skin or eyes with the liquid can cause frostbite or burns
[Hathaway et al. 1991].
* Signs and symptoms of exposure
1. Acute exposure: Lightheadedness, giddiness, disorientation, shortness
of breath, and cardiac irregularities may occur as a result of exposure to
high concentrations. Contact of the skin or eyes with the liquid can cause
frostbite or burns [Genium 1993].
2. Chronic exposure: No signs or symptoms of chronic exposure to
dichlorotetrafluoroethane have been reported in humans.
EMERGENCY MEDICAL PROCEDURES
* Emergency medical procedures: [NIOSH to supply]
5. Rescue: Remove an incapacitated worker from further exposure and
implement appropriate emergency procedures (e.g., those listed on the
Material Safety Data Sheet required by OSHA's Hazard Communication Standard
[29 CFR 1910.1200]). All workers should be familiar with emergency
procedures, the location and proper use of emergency equipment, and methods
of protecting themselves during rescue operations.
EXPOSURE SOURCES AND CONTROL METHODS
The following operations may involve dichlorotetrafluoroethane and lead to
worker exposures to this substance:
* The manufacture and transportation of dichlorotetrafluoroethane *
Used in nonflammable aerosol propellants; as a refrigerant in industrial
cooling and air conditioning systems * Used as a solvent, diluent, and
degreaser in the electronics and chemical industries; as a blowing agent in
manufacture of cellular polymers; and as an extractant for volatile
substances * Used in the manufacture of explosives, as a component of
dielectric fluid, and as a foaming agent in fire extinguishers
Methods that are effective in controlling worker exposures to
dichlorotetrafluoroethane, depending on the feasibility of implementation,
are as follows:
* Process enclosure * Local exhaust ventilation * General dilution
ventilation * Personal protective equipment
Workers responding to a release or potential release of a hazardous
substance must be protected as required by paragraph (q) of OSHA's Hazardous
Waste Operations and Emergency Response Standard [29 CFR 1910.120].
Good sources of information about control methods are as follows:
1. ACGIH [1992]. Industrial ventilation--a manual of recommended
practice. 21st ed. Cincinnati, OH: American Conference of Governmental
Industrial Hygienists.
2. Burton DJ [1986]. Industrial ventilation--a self study companion.
Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
3. Alden JL, Kane JM [1982]. Design of industrial ventilation systems.
New York, NY: Industrial Press, Inc.
4. Wadden RA, Scheff PA [1987]. Engineering design for control of
workplace hazards. New York, NY: McGraw-Hill.
5. Plog BA [1988]. Fundamentals of industrial hygiene. Chicago, IL:
National Safety Council.
MEDICAL SURVEILLANCE
OSHA is currently developing requirements for medical surveillance. When
these requirements are promulgated, readers should refer to them for
additional information and to determine whether employers whose employees are
exposed to dichlorotetrafluoroethane are required to implement medical
surveillance procedures.
* Medical Screening
Workers who may be exposed to chemical hazards should be monitored
in a systematic program of medical surveillance that is intended to prevent
occupational injury and disease. The program should include education of
employers and workers about work-related hazards, early detection of adverse
health effects, and referral of workers for diagnosis and treatment. The
occurrence of disease or other work-related adverse health effects should
prompt immediate evaluation of primary preventive measures (e.g., industrial
hygiene monitoring, engineering controls, and personal protective equipment).
A medical surveillance program is intended to supplement, not replace, such
measures. To detect and control work-related health effects, medical
evaluations should be performed (1) before job placement, (2) periodically
during the term of employment, and (3) at the time of job transfer or
termination.
* Preplacement medical evaluation
Before a worker is placed in a job with a potential for exposure to
dichlorotetrafluoroethane, a licensed health care professional should
evaluate and document the worker's baseline health status with thorough
medical, environmental, and occupational histories, a physical examination,
and physiologic and laboratory tests appropriate for the anticipated
occupational risks. These should concentrate on the function and integrity
of the respiratory system and cardiovascular system. Medical surveillance
for respiratory disease should be conducted using the principles and methods
recommended by the American Thoracic Society.
A preplacement medical evaluation is recommended to assess medical
conditions that may be aggravated or may result in increased risk when a
worker is exposed to dichlorotetrafluoroethane at or below the prescribed
exposure limit. The health care professional should consider the probable
frequency, intensity, and duration of exposure as well as the nature and
degree of any applicable medical condition. Such conditions (which should not
be regarded as absolute contraindications to job placement) include a history
and other findings consistent with diseases of the respiratory system or
cardiovascular system.
* Periodic medical evaluations
Occupational health interviews and physical examinations should be
performed at regular intervals during the employment period, as mandated by
any applicable Federal, State, or local standard. Where no standard exists
and the hazard is minimal, evaluations should be conducted every 3 to 5 years
or as frequently as recommended by an experienced occupational health
physician. Additional examinations may be necessary if a worker develops
symptoms attributable to dichlorotetrafluoroethane exposure. The interviews,
examinations, and medical screening tests should focus on identifying the
adverse effects of dichlorotetrafluoroethane on the respiratory system or
cardiovascular system. Current health status should be compared with the
baseline health status of the individual worker or with expected values for a
suitable reference population.
* Termination medical evaluations
The medical, environmental, and occupational history interviews, the
physical examination, and selected physiologic or laboratory tests that were
conducted at the time of placement should be repeated at the time of job
transfer or termination to determine the worker's medical status at the end
of his or her employment. Any changes in the worker's health status should
be compared with those expected for a suitable reference
population.
* Biological monitoring
Biological monitoring involves sampling and analyzing body tissues
or fluids to provide an index of exposure to a toxic substance or metabolite.
No biological monitoring test acceptable for routine use has yet been
developed for dichlorotetrafluoroethane.
WORKPLACE MONITORING AND MEASUREMENT
Determination of a worker's exposure to airborne dichlorotetrafluoroethane
is made using a two charcoal tubes in series (first tube 400/200 mg sections,
second tube 100/50 mg sections, both tubes 20/40 mesh). Samples are
collected at a maximum flow rate of 0.05 liter/minute until a maximum
collection volume of 4 liters is reached. The sample is then treated with
methylene chloride. Analysis is conducted by gas chromatography using a
flame ionization detector (GC/FID). This method is fully validated and is
described in the OSHA Computerized Information System [OSHA 1994] and in
NIOSH Method No. 1018 [NIOSH 1994b].
PERSONAL HYGIENE PROCEDURES
If dichlorotetrafluoroethane contacts the skin, workers should flush the
affected areas immediately with plenty of tepid water.
Clothing contaminated with dichlorotetrafluoroethane should be removed
immediately, and provisions should be made for the safe removal of the
chemical from the clothing. Persons laundering the clothes should be
informed of the hazardous properties of dichlorotetrafluoroethane.
A worker who handles dichlorotetrafluoroethane should thoroughly wash hands,
forearms, and face with soap and water before eating, using tobacco products,
using toilet facilities, applying cosmetics, or taking medication.
Workers should not eat, drink, use tobacco products, apply cosmetics, or
take medication in areas where dichlorotetrafluoroethane or a solution
containing dichlorotetrafluoroethane is handled, processed, or stored.
STORAGE
Dichlorotetrafluoroethane should be stored in a cool, dry, well-ventilated
area in tightly sealed containers that are labeled in accordance with OSHA's
Hazard Communication Standard [29 CFR 1910.1200]. Containers of
dichlorotetrafluoroethane should be protected from physical damage and heat
or ignition sources, and should be stored separately from alkalies or
alkaline earth metals such as sodium or potassium with calcium, zinc,
magnesium, or powdered aluminum.
SPILLS AND LEAKS
In the event of a spill or leak involving dichlorotetrafluoroethane, persons
not wearing protective equipment and clothing should be restricted from
contaminated areas until cleanup has been completed. The following steps
should be undertaken following a spill or leak:
1. Notify safety personnel.
2. Remove all sources of heat and ignition.
3. Ventilate the area of the spill or leak.
4. Stop leak if this can be done without risk.
5. If the source of the leak is a cylinder and the leak cannot be stopped
in place, remove the leaking cylinder to a safe place and repair the cylinder
or allow the cylinder to empty.
6. If the liquid is spilled or leaked, allow it to vaporize.
SPECIAL REQUIREMENTS
U.S. Environmental Protection Agency (EPA) requirements for emergency
planning, reportable quantities of hazardous releases, community
right-to-know, and hazardous waste management may change over time. Users
are therefore advised to determine periodically whether new information is
available.
* Emergency planning requirements
Dichlorotetrafluoroethane is not subject to EPA emergency planning
requirements under the Superfund Amendments and Reauthorization Act (SARA)
(Title III) in 42 USC 11022.
* Reportable quantity requirements for hazardous releases
A hazardous substance release is defined by EPA as any spilling,
leaking, pumping, pouring, emitting, emptying, discharging, injecting,
escaping, leaching, dumping, or disposing into the environment (including the
abandonment or discarding of contaminated containers) of hazardous
substances. In the event of a release that is above the reportable quantity
for that chemical, employers are required to notify the proper Federal,
State, and local authorities [40 CFR 355.40].
Employers are not required by the emergency release notification
provisions in 40 CFR Part 355.40 to notify the National Response Center of an
accidental release of dichlorotetrafluoroethane; there is no reportable
quantity for this substance.
* Community right-to-know requirements
Employers are not required by EPA in 40 CFR Part 372.30 to submit a
Toxic Chemical Release Inventory form (Form R) to EPA reporting the amount of
dichlorotetrafluoroethane emitted or released from their facility
annually.
* Hazardous waste management requirements
EPA considers a waste to be hazardous if it exhibits any of the
following characteristics: ignitability, corrosivity, reactivity, or
toxicity as defined in 40 CFR 261.21-261.24. Under the Resource Conservation
and Recovery Act (RCRA) [40 USC 6901 et seq.], EPA has specifically listed
many chemical wastes as hazardous. Although dichlorotetrafluoroethane is not
specifically listed as a hazardous waste under RCRA, EPA requires employers
to treat waste as hazardous if it exhibits any of the characteristics
discussed above.
Providing detailed information about the removal and disposal of
specific chemicals is beyond the scope of this guideline. The U.S.
Department of Transportation, EPA, and State and local regulations should be
followed to ensure that removal, transport, and disposal of this substance
are conducted in accordance with existing regulations. To be certain that
chemical waste disposal meets EPA regulatory requirements, employers should
address any questions to the RCRA hotline at (703) 412-9810 (in the
Washington, D.C. area) or toll-free at (800) 424-9346 (outside Washington,
D.C.). In addition, relevant State and local authorities should be contacted
for information on any requirements they may have for the waste removal and
disposal of this substance.
RESPIRATORY PROTECTION
* Conditions for respirator use
Good industrial hygiene practice requires that engineering controls
be used where feasible to reduce workplace concentrations of hazardous
materials to the prescribed exposure limit. However, some situations may
require the use of respirators to control exposure. Respirators must be worn
if the ambient concentration of dichlorotetrafluoroethane exceeds prescribed
exposure limits. Respirators may be used (1) before engineering controls
have been installed, (2) during work operations such as maintenance or repair
activities that involve unknown exposures, (3) during operations that require
entry into tanks or closed vessels, and (4) during emergencies. Workers
should only use respirators that have been approved by NIOSH and the Mine
Safety and Health Administration (MSHA).
* Respiratory protection program
Employers should institute a complete respiratory protection program
that, at a minimum, complies with the requirements of OSHA's Respiratory
Protection Standard [29 CFR 1910.134]. Such a program must include
respirator selection, an evaluation of the worker's ability to perform the
work while wearing a respirator, the regular training of personnel,
respirator fit testing, periodic workplace monitoring, and regular respirator
maintenance, inspection, and cleaning. The implementation of an adequate
respiratory protection program (including selection of the correct
respirator) requires that a knowledgeable person be in charge of the program
and that the program be evaluated regularly. For additional information on
the selection and use of respirators and on the medical screening of
respirator users, consult the latest edition of the NIOSH Respirator Decision
Logic [NIOSH 1987b] and the NIOSH Guide to Industrial Respiratory Protection
[NIOSH 1987a].
PERSONAL PROTECTIVE EQUIPMENT
Workers should use appropriate personal protective clothing and equipment
that must be carefully selected, used, and maintained to be effective in
preventing skin contact with dichlorotetrafluoroethane. The selection of the
appropriate personal protective equipment (PPE) (e.g., gloves, sleeves,
encapsulating suits) should be based on the extent of the worker's potential
exposure to dichlorotetrafluoroethane. There are no published reports on the
resistance of various materials to permeation by dichlorotetrafluoroethane.
To evaluate the use of PPE materials with dichlorotetrafluoroethane, users
should consult the best available performance data and manufacturers'
recommendations. Significant differences have been demonstrated in the
chemical resistance of generically similar PPE materials (e.g., butyl)
produced by different manufacturers. In addition, the chemical resistance of
a mixture may be significantly different from that of any of its neat
components.
Any chemical-resistant clothing that is used should be periodically
evaluated to determine its effectiveness in preventing dermal contact. Safety
showers and eye wash stations should be located close to operations that
involve dichlorotetrafluoroethane.
Splash-proof chemical safety goggles or face shields (20 to 30 cm long,
minimum) should be worn during any operation in which a solvent, caustic, or
other toxic substance may be splashed into the eyes.
In addition to the possible need for wearing protective outer apparel (e.g.,
aprons, encapsulating suits), workers should wear work uniforms, coveralls,
or similar full-body coverings that are laundered each day. Employers should
provide lockers or other closed areas to store work and street clothing
separately. Employers should collect work clothing at the end of each work
shift and provide for its laundering. Laundry personnel should be informed
about the potential hazards of handling contaminated clothing and instructed
about measures to minimize their health risk.
Protective clothing should be kept free of oil and grease and should be
inspected and maintained regularly to preserve its effectiveness.
Protective clothing may interfere with the body's heat dissipation,
especially during hot weather or during work in hot or poorly ventilated work
environments.
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