Chlorbutanol

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,1,1-trichloro-2-methyl-2-propanol hemihydrate

Cas Number:

6001-64-5

Molecular formula:

C4H7Cl3O H2O

IUPAC Name:

1,1,1-trichloro-2-methyl-2-propanol hemihydrate

Test material form:

solid: crystalline

Details on test material:

transparent and crystalline solid at ambient temperature

Test animals / tissue source

Species:

human

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

Replicate Amount
Tissue 1 50.2 mg
Tissue 2 51.0 mg

Duration of treatment / exposure:

6 hours

Duration of post- treatment incubation (in vitro):

18 hours

Number of animals or in vitro replicates:

2

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Remarks:

% Viability Mean

Run / experiment:

Mean

Value:

1.6

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Criterion Demanded Found
Mean OD of negative control > 0.8 and < 2.5 1.7
% mean relative viability of positive control < 50% of negative control 40.0%
Variation within replicates < 20% 0.1% (negative control)
4.1% (positive control)
0.1% (test item)

Any other information on results incl. tables

Designation	Positive Control	Chlorobutanol Hemihydrate
% Viability (Tissue 1)	37.9%	1.6%
% Viability (Tissue 2)	42.0%	1.6%
% Viability Mean	40.0%	1.6%

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

Under the conditions of the test, Chlorobutanol Hemihydrate is considered either eye irritant or inducing serious eye damage in the EpiOcularTM Eye Irritation Test.
After treatment with the test item, the mean value of relative tissue viability was reduced to 1.6 %. This value is well below the threshold for eye irritation potential (≤ 60%).
All validity criteria were met. The criterion for optical density of the negative control was fulfilled: The OD value was 1.7 (> 0.8 and < 2.5).
The positive control induced a decrease in tissue viability as compared to the negative control to 40.0 %. Variation within the replicates was acceptable (< 20%).
For these reasons, the result of the test is considered valid.

Executive summary:

One valid experiment was performed.

The test item Chlorobutanol Hemihydrate was applied to a three-dimensional human cornea tissue model in duplicate for an exposure time of 6 hours.

After treatment, the respective substance was rinsed from the tissue; then, cell viability of the tissues was evaluated by addition of MTT, which can be reduced to formazan. The formazan production was evaluated by measuring the optical density (OD) of the resulting solution.

Demineralised water was used as negative control and methyl acetate was used as positive control.

The controls showed the following results: After treatment with the negative control, the absorbance values were within the required acceptability criterion of mean OD>0.8 and < 2.5, OD was 1.7. The positive control showed clear eye irritating effects, the mean value of the relative tissue viability was 40.0 % (< 50%). 

Variation within tissue replicates was acceptable (< 20%).

 

After treatment with the test item, the mean value of relative tissue viability was 1.6 %. 

This value is well below the threshold for eye irritation potential (≤ 60%). Test items that induce values below the threshold are considered either eye irritant or inducing serious eye damage.

According to the OECD Guideline 492, the EpiOcular^TMEye Irritation Test does not allow discrimination between eye irritation/reversible effects on the eye (Category 2) and serious eye damage/irreversible effects on the eye (Category 1). For these purposes, further testing with other suitable test methods is required.