Submarine Exposure Guidance Levels for Selected Hydrofluorocarbons: HFC-236fa, HFC-23,and HFC-404a (2000)
Chapter: REFERENCES
Another consideration in the derivation of the EEGLs and CEGLs is the inhalation toxicokinetics of the HFCs. In general, the uptake of an inhaled HFC is a function of the rate of respiration (pulmonary ventilation), solubility of the HFC in the blood (blood:gas partition coefficient), pulmonary blood flow (cardiac output), and partial pressure of HFC in the blood. Because of the marked difference in pulmonary ventilation between rodents and humans, rodents will reach a constant HFC arterial pressure much more rapidly than will humans. These differences could be important for short-term exposures, but would likely be of less importance for long-term exposures where both humans and rodents would ultimately reach steady-state arterial concentrations of the gases.
STRUCTURE OF THE REPORT
The results of the subcommittee's evaluation of HFC-236fa, HFC-23, and HFC-404a are presented in Chapter 2, Chapter 3, and Chapter 4, respectively. For each agent, the subcommittee evaluates inhalation data on the toxicokinetics; acute, subchronic, and chronic toxicity; reproductive effects; developmental effects; genotoxicity; and carcinogenic effects. In addition, special consideration is given to data on cardiac sensitization because inhalation of HFCs and similar compounds are known to make the mammalian heart abnormally sensitive to epinephrine, resulting in cardiac arrhythmia and possibly death.
REFERENCES
NRC (National Research Council). 1986. Criteria and Methods of Preparing Emergency Exposure Guidance Level (EEGL), Short-Term Public Emergency Guidance Level (SPEGL), and Continuous Exposure Guidance Level (CEGL) Documents. Washington D.C: National Academy Press.
NRC (National Research Council). 1992. Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. Washington D.C: National Academy Press.
NRC (National Research Council). 1993. Guidelines for Developing Community Emergency Exposure Levels for Hazardous Substances. Washington D.C: National Academy Press.
NRC (National Research Council). 1996. Toxicity of Alternatives to Chlorofluorocarbons: HFC-134a and HCFC-123 . Washington D.C: National Academy Press.
