Section
5
Sealed System
5
-4
Inhalation Toxicity
Both R-410A and CFC 12, are very low in toxicity by
the inhalation route. The 4-hour LC
50
for R-410A is
greater than 520,000 ppm, and for CFC 12 it is 760,000
ppm. As with other halogenated hydrocarbons, CFC
12 and R-410A can, at high dose levels, sensitize the
heart to adrenaline. For CFC 12, the threshold level for
cardiac sensitization is 50,000 ppm, while for R-410A it is
100,000 ppm.
R-410A 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 R-410A 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 R-410A 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 R-410A vapors may
produce cardiac irregularities (cardiac sensitization),
unconsciousness, and with gross overexposure, death.
Intentional misuse or deliberate inhalation of R-410A
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.
Cardiac Sensitization
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 R-410A. 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.
Skin and Eye Contact
At room temperature, R-410A vapors have little or no
effect on the skin or eyes. However, in liquid form,
R-410A 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
R-410A. Where splashing is possible, always wear eye
protection and a face shield.
R-410A Physical Properties:
Chemical formula ....... 50% CH2F2 / 50% CHF2CF3
Molecular weight........ 72.6
Odor: ....................... Faint Ethereal Odor
Specific Gravity
(Water=1.0): ............ 1.08 @ 21.1°C (70°F)
PH: .......................... Neutral
Boiling Point: ............. -48.5°C (-55.4°F)
Freezing Point: ......... Not Determined
Vapor Pressure: ........ 215.3Psi@ 70°F/490.2Psi@ 130°F
Vapor Density
(Air = 1.0): .............. 3.0
Evaporation Rate: ..... >1
Compared To: CCl4= 1
% Volatiles: .............. 100
Flash Point: .............. Not Applicable
Evaporating Pressure (psi)...............................
Condensing Pressure (psi) ...............................
Compression Ratio ..........................................
Compressor Discharge Pressure °F...................
Temperature of Suction Gas °F........................
Specific Volume of Suction Vapor (cu. ft./lb).....
Latent Heat of Vaporization (Btu/lb.) ................
Net Refrigerating Effect (Btu/lb.)......................
Coefficient of Performance (C.O.P.)..................
Horsepower per Ton of Refrigerant ..................
Refrigerant Circulated per Ton (lbs/min)...........
Compressor Suction Gas Volume per Ton ***...
Liquid Circulated per Ton (cu. in./ min) ............
56.6
261.3
3.87
127
5
0.92
109.5
79.3
4.47
1.05
2.52
2.3
68.8
Summary of Contents for AF-S100RX
Page 8: ......
