1,1,1-trichloroethane

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Not standard methodology and inadequate documentation

Data source

Reference

Reference Type:

publication

Title:

Vapor toxicity of 1,1,1-trichloroethane (methyl-chloroform) determined by experiments on laboratory animals

Author:

ADAMS-EM; SPENCER-HC; ROWE-VK; IRISH-DD

Year:

1950

Bibliographic source:

ARCH-IND-HYG-OCCUP-MED 1 225-236

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

basic measurements only following 7 hour daily exposures for 5 days a week

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,1,1-trichloroethane

EC Number:

200-756-3

EC Name:

1,1,1-trichloroethane

Cas Number:

71-55-6

Molecular formula:

C2H3Cl3

IUPAC Name:

1,1,1-trichloroethane

Details on test material:

Redistilled commercial product, source not given.
Purity > 99 % (impurity was 1,2-dichloroethane)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Not specified

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Remarks on MMAD:

MMAD / GSD: not specified

Details on inhalation exposure:

Metal 300-litre box.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

sample flasks analysed by combustion and titration of inorganic chloride by the Volhard method. All concentrations within 10 % of nominal

Duration of treatment / exposure:

7 hours

Frequency of treatment:

3000 ppm:7 hour daily exposures for 5 days a week (47/48 exposures in 66/67 days)
5000 ppm: 7 hour daily exposures for 5 days a week (31 exposures in 44 days)

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
5000 ppm
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
3000 ppm
Basis:
nominal conc.

No. of animals per sex per dose:

5000 ppm 5 males and 5 females
3000 ppm 6 males and 7 females

Control animals:

yes, concurrent no treatment

Examinations

Observations and examinations performed and frequency:

Body wieght

Sacrifice and pathology:

Blood concentrations of urea nitrogen. Gross necropsy and histopathology of major organs only

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not specified

Details on results:

Clinical obsercations at 5000 ppm only - slight unsteadines and lethargy.
Slight reduction in body wieght gain in femails exposed to 5000 ppm in first week only (no data - start and terminal weights only)- no overall effect
No effect on final body weight, organ weight, blood cocentrations of urea nitrogen and histopathology

Effect levels

Dose descriptor:

LOEL

Effect level:

ca. 5 000 ppm

Sex:

male/female

Basis for effect level:

other: Reversible clinical signs after 7 hours exposure. No other notable effects. No effects at 3000 ppm

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Following repeated daily exposure of the male and female rat to the vapour (7 hours a day for 31 days over a 44 day period), only reversible clinical signs were observed at 5000 ppm; there were no effects on body weight, necropsy or pathology of major organs. There were no effects at 3000 ppm. 5000 ppm is therefore considered to be the LOEL. This was a none standard experiment, but the results are in a similar region as that reported by other investigators.

Executive summary:

Following repeated daily exposure of the male and female rat to the vapour (7 hours a day for 31 days over a 44 day period), only reversible clinical signs were observed at 5000 ppm; there were no effects on body weight, necropsy or pathology of major organs. There were no effects at 3000 ppm.  5000 ppm is therefore considered to be the LOEL. This was a none standard experiment, but the results are in a similar region as that reported by other investigators.