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Toxicological information

Specific investigations: other studies

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Administrative data

Endpoint:
specific investigations: other studies
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented study report which meets basic scientific principles - GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
30 minutes inhalation exposure to test material followed by body-only plethysmographs.
GLP compliance:
yes
Type of method:
in vivo

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Test animals

Species:
mouse
Strain:
Swiss Webster
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Sprague Dawley
- Weight at study initiation: 25-28 g
- Fasting period before study:
- Housing: Individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22
- Humidity (%): 40-60
- Photoperiod (hrs dark / hrs light): 12/12


Administration / exposure

Route of administration:
inhalation: vapour
Vehicle:
unchanged (no vehicle)
Details on exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: head isolated body-only plethysmograph
- Method of holding animals in test chamber: latex dam
- All glass chamber used for testing; 4 l volume
- T99 = < 3 minutes
- Test material vapor was generated by bubbling compressed air through the liquid test material contained inside 2 gas-washing bottles connected in series.
- The saturated test material vapor was then carried from the bubblers through a glass fiber filter, which trapped any condensation aerosol.
- Entire airflow for the animal exposure chambers was supplied by the bubblers in order to maintain a saturated vapor concentration.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Exposure concentrations were determined on both a nominal and actual basis. The nominal concentration was calculated by weighing the reservoir containing the test material before and after exposure and dividing the net loss in weight by the total volume of air passing through the chamber during exposure. Actual exposure concentrations were determined by drawing chamber air through a calibrated infrared monitor. The IR monitor was dynamically calibrated with a closed-loop calibration system by measuring the instrument's response in absorbance units against a series of concentrations of the test material in diluted air. Chamber concentrations were determined every five minutes. Values were then averaged to yield a mean chamber concentration for the exposure.
Duration of treatment / exposure:
At least 10 minutes of room air, 30 minutes of test material, and at least 5 minutes of room air recovery.
No. of animals per sex per dose:
4 males (111 ppm), 4 males (168 ppm)

Examinations

Examinations:
- Respiratory rates were determined from the oscillographic record. The average pretest rate and the lowest representative rate during exposure were determined for each animal in a group. The low rate was divided by the pretest rate to obtain a "Percent of Pretest" value. The Percent of Pretest value was subtracted from 100% to yield the animal response (Percent Change in Rate). Individual animals in each group were evaluated first, then averaged to determine the mean group response. The post-exposure rates were similarly evaluated to determine the recovery response= the percent return to pretest rates.

Results and discussion

Details on results:
The group mean respiratory rates were decreased 32% and 40% for animals exposed to 111 ppm and 168 ppm, respectively. All animals in both groups displayed breathing patterns characteristic of sensory (upper respiratory tract) irritation. No evidence of pulmonary (deep lung) irritation was observed. All animals survived until the end of the exposure. No animals exhibited any signs of ocular irritation.

Applicant's summary and conclusion

Conclusions:
Based on these data, classification under EU requirements for dangerous substances and preparations is not required. Additionally, classification under EU GHS guidelines is not required.
Executive summary:

The upper airway sensory irritation potential of isodecanol has been evaluated in male Swiss Webster mice.  Four mice per group received head-only exposures for 30 minutes to the test substance generated as a vapour at 111 and 168 ppm, 93 and 141 mg/l, respectively.  Respiratory rates were monitored throughout the exposure.  There were no deaths during the exposure or the following observation period.  There was no evidence of pulmonary irritation and none of the animals in either group showed ocular abnormalities.  The vapour concentration of 111 ppm resulted in a 32% decrease in breathing rate and the concentration of 168 resulted in a 40% decrease in breathing rate.  It is concluded that the approximate RD50 value in this study is 280 ppm.