The goal of this study was to develop a human physiologically based pharmacokinetic (PBPK) model for the chemical HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) and its major metabolite, trifluoroacetic acid (TFA). No human kinetic data for HCFC-123 are available, thus a corollary approach was developed. HCFC-123 is a structural analog of the common anesthetic agent halothane (2-bromo-2-chloro-1...

Four-Week Inhalation Toxicity Study of 2,2-Dichloro-1,1,1-trifluoroethane (HCFC-123) in Guinea Pigs: Isamu KABE, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University—Groups of eight male Hartley guinea pigs were exposed to 30, 100 or 300 ppm 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123) by inhalation for 6 hours a day for 4 wk. All the animals were sac...

Chlorodifluoromethane (HCFC-22) is one of the air pollutants that destroy ozone layer and warm earth. In order to degrade HCFC-22, catalytic hydrolysis method currently most effective environmental technology. Herein, we prepare solid acid MoO3/ZrO2 base MgO/ZrO2 catalysts for degradation with a particular focus on revealing effects catalyst preparation methods, calcination temperatures, temper...

This paper investigates the feasibility of hydrocarbon refrigerant mixtures as a replacement for HCFC-22 in residential air-conditioning and heat pump systems. The COP and the seasonal performance factor (SPF) were calculated using a UA-model for single component refrigerants and refrigerant mixtures. Simulations were run for pure propane and the mixtures of propane/i-pentane, propane/n-butane,...

A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself obj...

2,2-Dichloro-1,1,1-trifluoroethane (HCFC-123; CAS No. 306-83-2), a colorless light-ether-odor liquid with a boiling point of 27.6°C (at 1 Torr) and an ozone depletion potential of 0.02, is a substitute for a well-known ozone depleting substance trichlorofluoromethane (CFC-11) as a refrigerant, and 500 tons a year was shipped in Japan in 1996 according to the statistics surveyed by the Japan Flu...

According to the results of the international testing program AREP, the most likely replacements for HCFC-22 refrigerant will be blends of HFCs. However, as concerns about their global warming potential increase, other options should also be considered. As a naturally occurring substance, propane would be an ideal refrigerant, except for its flammability. When dealing with a flammable refrigera...

The influence of different environmental factors on methane oxidation and degradation of hydrochlorofluorocarbons (HCFCs) was investigated in microcosms containing soil sampled at Skellingsted Landfill, Denmark. The soil showed a high capacity for methane oxidation resulting in a maximum oxidation rate of 104 microg CH4 g(-1) h(-1) and a low affinity of methane with a half-saturation constant o...

HCFC-22 (CHClF2) and HFC-134a (CH2FCF3) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ozone depletion, and both species are potent greenhouse gases. In this work, we study in situ observations of HCFC-22 and HFC-134a taken from research aircraft over the Pacific Ocean in a 3-y span [HIaper-Pole-to...

The compound HFC-23 (Trifluoromethane or CHF3), a potent greenhouse gas with a 100-year global warming potential of 11,700, is generated as a by-product during the manufacture of HCFC-22 (chlorodifluoromethane or CHClF2). This paper outlines options and issues for good practice guidance in the national inventory management of HFC-23 emissions from HCFC-22 production. The issues presented are or...