Registration Dossier

Administrative data

Endpoint:
eye irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2009-11-24
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the appropriate OECD guideline and in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Guideline:
other: OECD 437 (BCOP)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Test animals / tissue source

Species:
other: cow
Strain:
not specified
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
in vitro - not applicable.
Bovine cornea.

Test system

Vehicle:
unchanged (no vehicle)
Controls:
other: negative and positive control groups
Amount / concentration applied:
750 ul
Duration of treatment / exposure:
10 minutes contact
Observation period (in vivo):
n/a
Number of animals or in vitro replicates:
3 corneas per group (TS, negative and positive controls)
Details on study design:
The assay uses isolated bovine corneas as a means of assessing the ocular corrosivity or severe irritancy potential of test substances in vitro. The isolated corneas were obtained as a by-product of the meat production industry. Two endpoints, corneal opacity and permeability, were measured and combined to give an In Vitro Irritancy Score which can be used to classify and rank test substances as potential eye irritants according to OECD guideline 437.

Corneas were treated in triplicate with either the test substance (neat), positive control (ethanol 100%) or negative control (0.9% sodium chloride solution). 750 ul was introduced into the anterior part of each holder. The anterior compartment was then plugged and the holder turned to a horizontal position and rotated to ensure distribution of the test substance over the corneal surface. Contact was maintained for 10 minutes.

Opacity was determined before and after treatment using an Opacitometer to measure light transmission. The change in opacity was calculated by subtracting the initial value from the post-treatment value and correcting for the mean change in opacity for the negative control.

Permeability was determined using sodium fluorescein. The corrected permeability value was similarly determined by subtracting the mean negative control value.

The in vitro irritancy score (IVIS) = corrected opacity value + (15x corrected permeability value). IVIS >= 55.1 indicates corrosive (severe irritant).

The positive control should elicit an In Vitro Irritancy Score that falls within two standard deviations of the historical mean for the laboratory. The negative control mean opacity change value should be <=2.0 and the permeability mean value <=0.1.

Results and discussion

In vivo

Results
Irritation parameter:
other: IVIS
Basis:
mean
Remarks:
3 in vitro bovine corneas
Time point:
other: n/a
Score:
107
Irritant / corrosive response data:
The test substance, ethylthioethanol, elicited an In Vitro Irritancy Score (IVIS) of 107.0 ± 15.1 and was predicted to be a corrosive/severe eye irritant.
Positive control IVIS = 49.0 +/- 6 (within 2 standard deviations of the historical range: 31.1-63.6)
Negative control IVIS = -0.333 (below the maximum acceptable value of 2.0)

Applicant's summary and conclusion

Interpretation of results:
Category 1 (irreversible effects on the eye)
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
A limited in vitro study, conducted in bovine cornea according to the guideline (OECD 437) and GLP, reported an In Vitro Irritancy Score of 107 indicating that the test material was likely to cause corrosion or severe irritation to the eyes.