1-chloro-1,1-difluoroethane

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Non-GLP near-guideline study, available as unpublished report, no restrictions, fully adequate for assessment (SIDS score: 1c)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Principles of method if other than guideline:

90-day inhalation study in dogs and rats

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-chloro-1,1-difluoroethane

EC Number:

200-891-8

EC Name:

1-chloro-1,1-difluoroethane

Cas Number:

75-68-3

Molecular formula:

C2H3ClF2

IUPAC Name:

1-chloro-1,1-difluoroethane

Details on test material:

- Substance name: 1-chloro 1,1-difluoroethane , Fluorocarbon 142b
- The test-material was presented as compressed form in several 125 lbs gas cylinders with a purity level of 99.7 %
- Batch number: Haskell Laboratory No. 9786

Radiolabelling:

no

Test animals

Species:

other: rats and dogs

Strain:

other: ChR-CD and Beagle, respectively

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Rats:
- Age at study initiation: young adults
- Weight at study initiation: 136-173 g females, 145-222 g males
- Diet: ad libitum
- Water: ad libitum

Dogs:
- Age at study initiation: 10-12 months
- Weight at study initiation: 12.3-15.9 kg each
- Diet: ad libitum
- Water: ad libitum

Administration / exposure

Route of administration:

inhalation: gas

Vehicle:

unchanged (no vehicle)

Details on exposure:

- Exposure apparatus: 1.4 m3 stainless steel chambers, dynamic exposure
- Test atmosphere generation: vapors from cylinders (heated to ~ 100 F) were metered into air streams supplying the chambers.
- Brief description of analytical method used: microprocessor controlled gas chromatograph with a flame ionization detector and an SE 30 column heated to 70 oC

Duration and frequency of treatment / exposure:

90 days

Doses / concentrations

Remarks:

Doses / Concentrations:
6 hours per day, 5 days per week

No. of animals per sex per dose / concentration:

Rats: 27/sex/dose
Dogs: 4 males/dose

Control animals:

yes, concurrent vehicle

Details on study design:

Post-exposure period: none

Details on dosing and sampling:

At monthly intervals, 10 rats/sex/level and all dogs were subjected to usual basic exams for:
- hemathology (measurements of red cell count, hemoglobin, hematoctit, total and differential white cell count)
- urinalysis (measurements of volume, osmolalityk creatinine, pH and fluoride ion concentration; tests for the presence of sugar, blood, acetone, bilirubin and protein, and a microscopic examination of the sediment)
- blood chemistry (measurements of alkaline phosphatase, glutamic-oxalacetic transaminase, glutamic pyruvic transaminase, lactic dehydrogenase and bilirubin

After 90 days of exposure, at the time of necropsy, tissue samples were collected from five rats/sex/level and four dogs/level for FC-142b analysis. An interval of 18 to 48 hours occurred between the time of the last exposure and sample collection. The tissues analyzed in rats were the adrenals, blood, brain and fat. The tissues analyzed in dogs were arterial blood, heart, lung, kidney, liver, spleen, adrenals, fat, brain and muscle.

Statistics:

Not specified

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on absorption:

Studies in rats exposed by inhalation show  that 1-chloro-1,1-difluoroethane is rapidly absorbed by the lungs. 

Details on distribution in tissues:

No test substance was found in any of the tissues analyzed from animals sacrificed 18 to 48 hours after the last exposure.

Details on excretion:

No significant increase in urinary fluoride was detected in test animals during the 90-day study, suggesting little or no metabolism of this fluorocarbon.

Metabolite characterisation studies

Metabolites identified:

no

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): no bioaccumulation potential based on study results
No test substance was found in any of the tissues analyzed from animals sacrificed 18 to 48 hours after the last exposure in 90-day inhalation toxicity study.

Executive summary:

The substance is rapidly absorbed from lungs and rapidly eliminated. No significant increase in urinary fluoride of the test animals suggests little or no metabolism.