2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 August 2016 (Study Plan dated) to 30 January 2017 (Final Report dated)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

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:

26 July 2013

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

EC Number:

239-044-2

EC Name:

2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

Cas Number:

14970-87-7

Molecular formula:

C6H14O2S2

IUPAC Name:

2,2'-[1,2-ethanediylbis(oxy)]bis(ethanethiol)

Test material form:

liquid

Test animals / tissue source

Species:

other: Bos primigenius taurus

Details on test animals or tissues and environmental conditions:

Isolated corneas from the eyes of freshly slaughtered bovine (age of animal: 12-60 months)

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

750 microliter

Duration of treatment / exposure:

10 minutes at 32°C +/- 1°C

Duration of post- treatment incubation (in vitro):

1 hour and 55 minutes at 32°C +/- 1°C

Number of animals or in vitro replicates:

3 fresh bovine corneas

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing
- Time after start of exposure:10 minutes

SCORING SYSTEM: Final opacity value of each cornea
Fluorescein permeability after 85 minutes of incubation at 32 +/- 1°C

TOOL USED TO ASSESS SCORE: opacitometer (opacity), spectrophotometer at 492 nm (permeability)

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Value:

ca. 4.75

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

IVIS = 0.12

Positive controls validity:

valid

Remarks:

IVIS = 82.08

Applicant's summary and conclusion

Interpretation of results:

other: Not classified eye damage category 1

Conclusions:

The test item DMDO induces effects on the cornea, that cannot be classified in an UN GHS Category for eye damage

Executive summary:

The study was performed to assess corneal damage potential of DMDO by quantitative measurements of changes in opacity and permeability in a bovine cornea. DMDO was brought onto the cornea of a bovine eye which previously had been incubated with cMEM without phenol red at 32 +/- 1°C for 1 hour and whose opacity had been determined. DMDO was incubated on the cornea for 10 minutes at 32 +/- 1°C. After removal of the test item and 1 hour and 55 minutes post-incubation, opacity and permeability values were measured. The negative control (HBSS-solution) and the positive control (undiluted dimethylformamide) have met the validity criteria. No observations were made which might cause doubts concerning the validity of the study outcome. The test is considered valid. DMDO was tested as pure. Under the condition of this test , DMDO showed effects on the cornea of the bovine eye. The calculated IVIS (in vitro irritancy score) is 4.75. According to the OECD Guideline no. 437 (July 2013), a substance with an IVIS >3 and <= 55 induces effects on the cornea, that cannot be classified in an UN GHS Category for eye damage. Nevertheless, the result did not warrant a classifiucation as eye damage category 1.