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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Basic toxicokinetics

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Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: 2e Study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Pentahalotane-based chlorofluorocarbon substitutes and halotane: correlation of in vivo hepatic protein trifluoroacetylation and urinary trifluoro acetic acid excretion with calculated enthalpies of activation
Author:
Harris, J.W., Jones, J.P., Martin, J.L., La Rossa, A.C., Olson, M.J., Pohl, L.R. and Anders, M.W.
Year:
1992
Bibliographic source:
Chem. Res. Toxicol. 5, 720-25

Materials and methods

Objective of study:
metabolism
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Pentafluoroethane
EC Number:
206-557-8
EC Name:
Pentafluoroethane
Cas Number:
354-33-6
Molecular formula:
C2HF5
IUPAC Name:
1,1,1,2,2-pentafluoroethane
Radiolabelling:
no

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male/female

Administration / exposure

Route of administration:
inhalation
Vehicle:
other: air
Duration and frequency of treatment / exposure:
6 hour(s)
Doses / concentrations
Remarks:
Doses / Concentrations:
Males: 1%
No. of animals per sex per dose / concentration:
Males: 6

Results and discussion

Toxicokinetic / pharmacokinetic studies

Toxicokinetic parametersopen allclose all
Toxicokinetic parameters:
half-life 1st:
Toxicokinetic parameters:
half-life 2nd:
Toxicokinetic parameters:
half-life 3rd:

Metabolite characterisation studies

Metabolites identified:
yes
Details on metabolites:
Low metabolisation to trifluoroacetic acid (TFA) was observed

Any other information on results incl. tables

The semi-quantitative analysis of immunoblotted TFA-proteins indicated a decreasing potential to form TFA-proteins, in this order:

Halotane>=HCFC-123>>HCFC-124>HFC-125.

No quantitative analysis of TFA-protein amount was carried out.
TFA-proteins were not detected in samples from rats exposed to HFC-134a.

19F-NMR analysis of urinary TFA excretion after 12 hrs from the end of exposure confirmed the previous data:

Halocarbon

TFA excretion (umol/kg)

halothane

65 +/- 16

HCFC-123

82 +/- 20

HCFC-124

16 +-/ 2

HFC-125

1.7 +/- 1.7


Applicant's summary and conclusion

Executive summary:

The study was aimed to determine the potential of various halogenated ethanes to form trifluoroacetylated-proteins following their metabolisation in the liver. Fisher rats were exposed to halothane (1.1%, n=6), HCFC-124 (1%, n=6), HFC-125 (0.97%, n=6), HCFC-123 (1.1%, n=6) and HFC-134a (1%, n=3) for 6 hours. At the end of the exposure, the urine were collected and analysed by 19F-NMR to measure the TFA excretion. 12 hours after after the exposure period termination, animals were sacrificed, liver was homogenized and cytosolic and microsomal fractions prepared. Protein of the subcellular fractions were separated by SDS-PAGE and immunoblotted with anti-TFA-protein serum.

HFC-125 showed a low potential to form TFA in liver, compared to other halogenated ethanes.