Table of Contents
Advertisement
I I n n h h a a l l a a t t i i o o n n T T o o x x i i c c i i t t y y
HFC-134a poses no acute or chronic hazard when
it is handled in accordance with DuPont
recommendations and when exposures are
maintained at or below the DuPont Acceptable
Exposure Limit (AEL) of 1,000 ppm (8 and 12 hour
Time-Weighted Average or TWA).
An AEL is an airborne exposure limit established
by DuPont scientists that specifies time-weighted
average (TWA) airborne concentrations to which
nearly all workers may be repeatedly exposed
without adverse effects. The AEL for HFC-134a
has the same value as the Threshold Limit Values
(TLVs) established for CFC-12 and HCFC-22. TLVs
are established by the American Conference of
Governmental and Industrial Hygienists (ACGIH).
However, inhaling high concentrations of
HFC-134a vapor may cause temporary central
nervous system depression with narcosis, lethargy
and anesthetic effects. Other effects that may
occur include dizziness, a feeling of intoxication
and a loss of coordination. Continued breathing of
high concentrations of HFC-134a vapors may
produce cardiac irregularities (cardiac
sensitization), unconsciousness, and with gross
overexposure, death. Intentional misuse or
deliberate inhalation of HFC-134a may cause
death without warning. This practice is extremely
dangerous.
If you experience any of the initial symptoms,
move to fresh air and seek medical attention.
C C a a r r d d i i a a c c S S e e n n s s i i t t i i z z a a t t i i o o n n
If vapors are inhaled at a concentration of 75,000
ppm, which is well above the AEL, the heart may
become sensitized to adrenaline, leading to
cardiac irregularities and, possibly, to cardiac
arrest. The likelihood of these cardiac problems
increases if you are under physical or emotional
stress.
Medical attention must be given immediately if
exposed to high concentrations of HFC-134a. DO
NOT treat with adrenaline (epinephrine) or similar
drugs. These drugs may increase the risk of
cardiac arrhythmia and cardiac arrest. If the
person is having difficulty breathing, administer
oxygen. If breathing has stopped, give artificial
respiration.
R R e e f f r r i i g g e e r r a a t t i i o o n n S S y y s s t t e e m m
S S p p i i l l l l s s o o r r L L e e a a k k s s
If a large release of vapor occurs, such as from a
large spill or leak, the vapors may concentrate near
the floor or low spots and displace the oxygen
available for breathing, causing suffocation.
Evacuate everyone until the area has been
ventilated. Use blowers or fans to circulate the air
at floor level. DO NOT re-enter the affected area
unless you are equipped with a self-contained
breathing apparatus or unless an area monitor
indicates that the concentration of HFC-134a
vapors in the area is below the AEL.
Always use self-contained breathing apparatus or
an air-line mask when entering tanks or other areas
where vapors might exist. Use the buddy system
and a lifeline. Refer to the Material Safety Data
Sheet (MSDS) for HFC-134a for more information.
HFC-134a vapors have a slightly sweet odor that
can be difficult to detect. Therefore, frequent leak
checks and the installation of permanent area
monitors may be necessary in enclosed spaces.
Refer to ASHRAE Standards 15 and 34 for
refrigeration machinery rooms.
To ensure safety when working with HFC-134a in
enclosed areas:
1. Route relief and purge vent piping (if present)
outdoors, away from air intakes.
2. Make certain area is well ventilated, using
auxiliary ventilation if needed to move vapors.
3. Make sure area is clear of vapors prior to
beginning work.
4. Install air monitoring equipment to detect
leaks.
S S k k i i n n a a n n d d E E y y e e C C o o n n t t a a c c t t
At room temperature, HFC-134a vapors have little
or no effect on the skin or eyes. However, in liquid
form, HFC-134a can freeze skin or eyes on
contact, causing frostbite. Following contact, soak
the exposed area in lukewarm water, not cold or
hot. If medical treatment cannot begin
immediately, apply a light coat of a nonmedicated
ointment, such as petroleum jelly. If the exposed
area is in a location where the presence of the
ointment would be awkward, such as on the eye,
apply a light bandage. In all cases of frostbite,
seek medical attention as soon as possible.
Always wear protective clothing when there is a
risk of exposure to liquid HFC-134a. Where
splashing is possible, always wear eye protection
and a face shield.
4-17
Advertisement
Table of Contents
