Submarine Exposure Guidance Levels for Selected Hydrofluorocarbons: HFC-236fa, HFC-23,and HFC-404a (2000)
Chapter: TOXICOKINETICS
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Common name: |
HFC-23 |
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Chemical name: |
Trifluromethane |
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Synonyms: |
Freon 23, Genetron 23, fluoroform, HC-23, fluoryl, Arcton 1, carbon trifluoride, halocarbon 23, methyl trifluoride, R 23, FE-13 |
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CAS number: |
75-46-7 |
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Structural formula: |
HCF3 |
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Description: |
Colorless gas |
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Molecular weight: |
70.01 |
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Boiling point: |
-82.03°C at 760 mm Hg |
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Melting point: |
-155.2°C |
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Density and specific gravity: |
0.670 g/mL at 25°C |
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Vapor pressure: |
686 psig at 25°C (77°F) |
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Vapor density: |
2.4 (Air = 1.0) |
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Flash point and flammability: |
Nonflammable |
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Solubility: |
0.10 wt% in water |
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Autoignition: |
765°C (1409°F) |
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Octanol and water partition coefficient: |
Kow = 0.64 |
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Conversion factors: |
1 mg/m3= 0.35; 1 ppm = 2.86 mg/m3> |
TOXICOKINETICS
Ewing et al. (1990) studied the use of HFC-23 in nuclear magnetic resonance spectroscopy as a gaseous indicator of cerebral blood flow in cats. HFC-23 at a concentration of 600,000 ppm was rapidly absorbed from the lungs and the arterial blood concentration reached a plateau within 3 or 4 min after initiation of the exposure. Likewise, HFC-23 was rapidly eliminated from the blood upon termination of the exposure. It was also rapidly taken up by the brain, with the brain uptake lagging the arterial blood uptake by about 2 min. Similar findings were demonstrated with 670,000 ppm by Detre et al. (1990) in the rat.
