Tetrahydrothiophene

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 81-4 (Acute Eye Irritation)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Tetrahydrothiophene

EC Number:

203-728-9

EC Name:

Tetrahydrothiophene

Cas Number:

110-01-0

Molecular formula:

C4H8S

IUPAC Name:

tetrahydrothiophene

Details on test material:

Source: Pennwalt Corporation
Batch: 113-539-84
Purity: no data

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Hazleton-Dutchland, Inc.3 , Denver, PA
- Age at study initiation: young adults
- Weight at study initiation: no data
- Housing: individually
- Diet (e.g. ad libitum): Lab Rabbit Chow HF (Purina #5326)
- Water (e.g. ad libitum): tap water
- Acclimation period: 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 60-70
- Humidity (%): 30-70
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Amount applied: 0.1 ml

Duration of treatment / exposure:

The appropriate amount of the test material was introduced into the lower conjunctival sac of the right eye of each animal. The upper and lower lids were gently held together for one second prior to releasing to prevent loss of material. The contralateral eye served as the control.

No wash was performed after application of the material. However, approximately 24 hours after application, the treated eye was rinsed to remove any residual test material.

Observation period (in vivo):

- Intervals:
Approximately 1, 24, 48 and 72 hours and 7 and 10 days after treatment, or until no signs of irritation were present.
- Method:
At interval the treated and control eyes were examined and scored for ocular reactions according to the Draize scale. Fluorescein dye was used to confirm presence or absence of corneal ulceration in treated eyes starting with the 24 hour observation and at each subsequent observation until there was no stain retention for two observations. Unusual effects such as pannus, blistering of the conjunctiva, ulceration and other effects indicative of corrosive action were also noted when present.

Number of animals or in vitro replicates:

6

Details on study design:

Preparation of Animals:
On the day before dosing, both eyes of each animal were examined using fluorescein dye to check for presence of corneal ulceration. Just prior to test substance application, the eyes were examined again, but without fluorescein. Animals showing pre-existing corneal or conjunctival injury or irritation were not placed on study.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24 + 48 + 72 h

Score:

2.27

Max. score:

3

Reversibility:

fully reversible within: 10 days

Results 2

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24 + 48 + 72 h

Score:

1.16

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 3

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24 + 48 + 72 h

Score:

0.11

Max. score:

2

Reversibility:

fully reversible within: 72 h

Results 4

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24 + 48 + 72 h

Score:

0.55

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

Tetrahydrothiophene produced moderate to severe but reversible ocular irritation. All six animals exhibited severe conjunctival irritation (redness, chemosis, discharge, necrosis) and iritis and three exhibited corneal opacity and ulceration. Three animals were noted to have hair loss around the eye. The most severe conjunctival and iridial effects occurred one hour after instillation of the test material and corneal effects were most severe at 24 hours. Recovery was apparent, however, and all six animals were free of ocular irritation within 7 to 10 days after instillation of the test material.

Applicant's summary and conclusion

Interpretation of results:

Category 2A (irritating to eyes) based on GHS criteria

Conclusions:

A transient conjunctivitis and/or corneal opacity are observed after acute instillation in the eye of rabbits.

Executive summary:

In a study performed according to EPA guideline #OPP 81-4 and GLP, 0.1 ml of Tetrahydrothiophene was instillated in the conjunctival sac of 6 rabbits. Eye reactions were evalutated 1, 24, 48, 72 hours and 7 and 10 days after the initial administration. No wash was performed after application of the material.
Tetrahydrothiophene produced moderate to severe but reversible ocular irritation. All six animals exhibited severe conjunctival irritation (redness, chemosis, discharge, necrosis) and iritis and three exhibited corneal opacity and ulceration. Three animals were noted to have hair loss around the eye. The most severe conjunctival and iridial effects occurred one hour after instillation of the test material and corneal effects were most severe at 24 hours. Recovery was apparent, however, and all six animals were free of ocular irritation within 7 to 10 days after instillation of the test material. Mean scores over 24, 48 and 72h were 2.27, 1.16, 0.11 and 0.55 for conjunctival redness and chemosis, iritis and corneal opacity, respectively.
According to these results, tetrahydrothiophene should be considered as irritant for the eyes.