4,4,19,19-tetraethoxy-3,20-dioxa-8,15-dithia-4,19-disiladocosaneand S-(6-{[3-(triethoxysilyl)propyl]thio}hexyl) ethanethioate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 2020 - December 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Version / remarks:

09 October 2017

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4,4,19,19-tetraethoxy-3,20-dioxa-8,15-dithia-4,19-disiladocosane and S-(6-{[3-(triethoxysilyl)propyl]thio}hexyl) ethanethioate

EC Number:

951-696-6

Molecular formula:

C17H36O4S2Si and C24H54O6S2Si2

IUPAC Name:

4,4,19,19-tetraethoxy-3,20-dioxa-8,15-dithia-4,19-disiladocosane and S-(6-{[3-(triethoxysilyl)propyl]thio}hexyl) ethanethioate

Test material form:

liquid

Test animals / tissue source

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

The assay uses isolated corneas obtained as a by-product from animals freshly slaughtered.
On the test day, fresh eyes were collected from the slaughterhouse and were transported in HBSS containing Pen/Strep on ice to the laboratories. Immediately after arrival of the eyes, cornea preparation was initiated.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

750 µL of the test substance or the control substance was introduced into the anterior chamber.

Duration of treatment / exposure:

10 minutes incubation at 32  1 °C

Number of animals or in vitro replicates:

3 corneas for the test item
3 corneas as negative controls treated with physiological saline 0.9% NaCl
3 corneas as positive controls treated with ethanol 100%

Details on study design:

The eyes were carefully examined for defects and any defective eyes were discarded.
The tissue surrounding the eyeball was carefully pulled away and the cornea was excised leaving a 2 to 3 mm rim of sclera. The isolated corneas were stored in a petri dish containing HBSS. Before the corneas were mounted in corneal holders (Duratec GmbH) with the endothelial side against the O-ring of the posterior chamber, they had been visually examined for defects and any defective cornea had been discarded. The anterior chamber was then positioned on top of the cornea and tightened with screws. The chambers of the corneal holder were then filled with RPMI 1640 medium (without phenol red) containing 1% FBS and 2 mM L-glutamine (complete RPMI 1640 medium). The posterior chamber was always filled first. The corneas were incubated for one hour at 32  1 °C
After the illuminance measurement was performed, the medium was removed from both chambers of the holder. The posterior chamber was refilled with fresh complete RPMI 1640 medium. 1 mL of a 4 mg/mL sodium fluorescein solution was added to the anterior chamber and the corneas were incubated for 90 minutes at 32  1 °C. Then the medium from the posterior chamber was removed and its optical density at 490 nm (OD490) was determined, using a spectrophotometer (Jenway 6405 UV/VIS).

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Value:

0.45

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid.
The negative control responses resulted in opacity and permeability values that are less than the established upper limits for background bovine corneas treated with the respective negative control.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

According to the evaluation criteria the test item is classified into UN GHS No Category.

Executive summary:

The eye irritancy potential of Reaction mass of the test substance was investigated in the bovine corneal opacity and permeability assay.

None of the corneas treated with the test substance showed any opacity of the tissue.

The following meanin vitroirritation score was calculated:

0.45

Therefore the test item was classified intoUN GHS No Category.