Metabolism and pharmacokinetics of selected Halon replacement candidates

Dodd, DE; Brashear, WT; Vinegar, A

HERO ID

68379

Reference Type

Journal Article

Year

1993

Language

English

PMID

8516773

HERO ID 68379
In Press No
Year 1993
Title Metabolism and pharmacokinetics of selected Halon replacement candidates
Authors Dodd, DE; Brashear, WT; Vinegar, A
Journal Toxicology Letters
Volume 68
Issue 1-2
Page Numbers 37-47
Abstract The metabolism and pharmacokinetic characteristics of 1,1-dichloro-2,2,2-trifluoroethane (306832) (HCFC-123), 2-chloro-1,1,1,2-tetrafluoroethane (2837890) (HCFC-124), 1-chloro-1,1-difluoroethane (75683) (HCFC-142b), and perfluorohexane (355420) (PFH) were studied in rats. The study was part of a program to investigate possible health hazards presented by candidate Halon replacements for use as a fire extinguishant. Male Fischer-344-rats and Sprague-Dawley-rats were exposed nose only to 10,000 parts per million (ppm) HCFC-123, HCFC-124, HCFC-142b, or PFH for 2 hours. Urine samples were collected for 24 hours. The rats were killed 0 or 24 hours after exposure and the tissue distribution of the compounds and their metabolites was determined by gas chromatography and fluorine-19 nuclear magnetic resonance spectroscopy. HCFC-123, HCFC-124, HCFC-142b, and PFH were detected in all tissues of rats killed immediately after exposure. 2-Chloro-1,1,1-trifluoroethane (75887) (HCFC-133a) and 2-chloro-1,1-difluoroethylene (359104) were detected in the livers of rats exposed to HCFC-123. HCFC-133a was also detected in the kidneys. Most tissue concentrations of the halocarbons and metabolites were below the detection limit in rats examined 24 hours post exposure. Rats exposed to HCFC-123 and HCFC-124 excreted trifluoroacetic-acid (76051) (TFA) in their urine. Rats exposed to HCFC-142b excreted chlorodifluoroacetic-acid. No PFH metabolites were detected. F344-rats were exposed to 0 to 25,0O0ppm HCFC-123 for 2 to 4 hours. They were killed at various times up to 24 hours after exposure and the urine, blood, and tissues were taken for HCFC-123, TFA, and HCFC-133a analysis. The data were fit to the Hoover physiologically based pharmacokinetic model. Blood TFA concentrations increased during exposure and for up to 5 hours afterwards before slowly decreasing. The metabolism of HCFC-123 to TFA and HCFC-133a became saturated at 2,000ppm HCFC-123. The authors conclude that HCFC-133a may be a useful marker for pharmacokinetic modeling of HCFC-123.
Doi 10.1016/0378-4274(93)90117-G
Pmid 8516773
Wosid WOS:A1993LH57700008
Is Certified Translation No
Dupe Override No
Conference Location WRIGHT PATTERSON AFB, OH
Conference Name CONF ON APPLICATIONS OF ADVANCES IN TOXICOLOGY TO RISK ASSESSMENT
Comments Toxicol. Lett. 68: 37-47.
Is Public Yes
Language Text English
Keyword Hydrochlorofluorocarbon; HCFC-123; HCFC-124; HCFC-142b; Perfluorohexane; Halon 1211; Trifluoroacetic acid
Is Qa No