Registration Dossier

Skin Irritation:

The treatment of mice with 1.25, 2.5, 5 and 10% test item in DMSO did not show any signs of severe local irritation or systemic toxicity. Due to the discolouration by the test

item redness at the ears caused by irritation could not be observed.

Hence, the test chemical can be considered to be not irritating to the skin of mice.

Eye Irritation:

Based on the available data for the various test chemicals and applying the weight of evidence approach, it can be concluded that the test chemical will also tend to behave in a similar manner. Therefore, the test chemical was estimated to be not irritating to eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

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Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Justification for type of information:

data is from guideline study

Qualifier:

according to guideline

Guideline:

other: OECD 429(Skin Sensitization: Local Lymph Node Assay)

Principles of method if other than guideline:

A pre-test was performed to determine the highest non-irritant test chemical concentration for the main LLNA assay

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): 3H,3'H-2,2'-bi-1-benzothiophene-3,3'-dione
- Common Name: Thioindigo
- Molecular formula: C16H8O2S2
- Molecular weight: 296.369 g/mol
- Smiles notation: O=C1c2c(S\C1=C1/Sc3c(cccc3)C1=O)cccc2
- InChl : 1S/C16H8O2S2/c17-13-9-5-1-3-7-11(9)19-15(13)16-14(18)10-6-2-4-8-12(10)20-16/h1-8H/b16-15-
- Substance type: Organic
- Physical state: Solid
- Purity: >95%(w/w)
- Batch No.: AAFE 094505
- Stability: 0.1 mg/ml 4h in DMSO, 50 mg/ml 72h in DMSO
- Storage: At room temperature
- Expiration Date: October 21, 2015
- Manufacturing Date: October 21, 2005

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Details on test animals or test system and environmental conditions:

Details on test animals and environmental conditions

Test Animals:

- Source: Harlan Netherlands
- Sex: Females
- Age: 6 - 12 weeks (beginning of acclimatization)
- Identification: Single caging. The animals will be distributed into the test groups at random and identified by cage number.
- Housing: single
- Cage Type: Makrolon Type I, with wire mesh top (EHRET GmbH, D-79302 Emmendingen) with granulated soft wood bedding (Harlan Winkelmann GmbH)
- Feed: pelleted standard diet, ad libitum (Harlan Winkelmann GmbH)
- Water: tap water, ad libitum, (Gemeindewerke, D-64380 Rossdorf)
- Acclimatisation: Under test conditions after health examination. Only animals without any visible signs of illness will be used for the study.

Environmental Conditions:

- Temperature: 22 + 3°C
- Relative humidity: 30-79%
- Artificial light: 6.00 a.m. - 6.00 p.m.

Type of coverage:

open

Preparation of test site:

not specified

Vehicle:

other: DMSO

Controls:

not specified

Amount / concentration applied:

1.25, 2.5, 5 and 10% (w/v)

Duration of treatment / exposure:

single exposure

Observation period:

no data available

Number of animals:

2 females

Details on study design:

The ears were observed for local irritation or systemic toxicity

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: no data available

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The treatment of mice with 1.25, 2.5, 5 and 10% test item in DMSO did not show any signs of severe local irritation or systemic toxicity. Due to the discolouration by the test
item redness at the ears caused by irritation could not be observed.

Interpretation of results:

other: not irritating

Conclusions:

The treatment of mice with 1.25, 2.5, 5 and 10% test item in DMSO did not show any signs of severe local irritation or systemic toxicity. Due to the discolouration by the test
item redness at the ears caused by irritation could not be observed.
Hence, the test chemical can be considered to be not irritating to the skin of mice.

Executive summary:

A pre-test was performed to determine the highest non-irritant test chemical concentration for the main LLNA assay.

1.25, 2.5, 5 and 10% (w/v) in DMSO were tested on one ear each of 2 female CBA/CaOlaHsd mice. The mice ears were observed for local irritation or systemic toxicity.

The treatment of mice with 1.25, 2.5, 5 and 10% test item in DMSO did not show any signs of severe local irritation or systemic toxicity. Due to the discolouration by the test

item redness at the ears caused by irritation could not be observed.

Hence, the test chemical can be considered to be not irritating to the skin of mice.

Endpoint conclusion:

no adverse effect observed (not irritating)

Reference

Endpoint:

eye irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: weight of evidence approach based on various test chemicals

Justification for type of information:

Weight of evidence approach based on various test chemicals

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

other: weight of evidence approach based on various test chemicals

Principles of method if other than guideline:

Weight of evidence approach based on various test chemicals

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): 3H,3'H-2,2'-bi-1-benzothiophene-3,3'-dione
- Common Name: Thioindigo
- Molecular formula: C16H8O2S2
- Molecular weight: 296.369 g/mol
- Smiles notation: O=C1c2c(S\C1=C1/Sc3c(cccc3)C1=O)cccc2
- InChl : 1S/C16H8O2S2/c17-13-9-5-1-3-7-11(9)19-15(13)16-14(18)10-6-2-4-8-12(10)20-16/h1-8H/b16-15-
- Substance type: Organic
- Physical state: Solid

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

no data available

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

1. undiluted
2. 7% alkaline solution

Duration of treatment / exposure:

single exposure

Observation period (in vivo):

1. no data available
2. Several hours to 10 days

Duration of post- treatment incubation (in vitro):

no data available

Number of animals or in vitro replicates:

no data available

Details on study design:

The study is based on weight of evidence approach from the read across values

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: no data available

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of irritation observed

Interpretation of results:

other: not irritating

Conclusions:

Based on the available data for the various test chemicals and applying the weight of evidence approach, it can be concluded that the test chemical will also tend to behave in a similar manner. Therefore, the test chemical was estimated to be not irritating to eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

Executive summary:

Based on the available studies for the various test chemicals, weight of evidence approach was applied to assess the ocular irritation potential of the test chemical.

The ocular irritation potential of the test chemical was assessed in rabbits.

The test chemical was applied to the conjunctival sac of rabbits and observed for signs of irritation (dose and duration not mentioned). There was neither local nor central action when the test chemical was applied to the conjunctival sac of rabbits.

Hence, the test chemical can be considered not irritating to rabbit eyes.

This is supported by a study which reports the accidental exposure of the other test chemical to the human eyes.

A man accidently splashed 7% alkaline solution of reduced form of the other test chemical into his eyes.

His conjunctiva appeared blue several hours later; cornea was somewhat turbid but not stained. In course of 10 days cornea gradually got cleared & some fine blue dots were seen in stroma. The test chemical appeared to be rather inert & nontoxic in human tissues.

Hence, the test chemical can be considered not irritating to human eyes.

Based on the available data for the various test chemicals and applying the weight of evidence approach, it can be concluded that the test chemical will also tend to behave in a similar manner. Therefore, the test chemical was estimated to be not irritating to eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

Endpoint conclusion:

no adverse effect observed (not irritating)

Endpoint conclusion:

no study available

Skin Irritation

In various studies,the test chemical has been investigated for potential to cause dermal irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits, mice for the target chemical as well as its structurally similar chemicals. The results are summarized as follows:

A pre-test was performed to determine the highest non-irritant test chemical concentration for the main LLNA assay.

1.25, 2.5, 5 and 10% (w/v) in DMSO were tested on one ear each of 2 female CBA/CaOlaHsd mice. The mice ears were observed for local irritation or systemic toxicity.

The treatment of mice with 1.25, 2.5, 5 and 10% test item in DMSO did not show any signs of severe local irritation or systemic toxicity. Due to the discolouration by the test item edness at the ears caused by irritation could not be observed.

Hence, the test chemical can be considered to be not irritating to the skin of mice.

This result is supported by the study performed toindicate the Comedogenicity and irritancy of the test chemical.

The test chemical was mixed in propylene glycol at a 9 to 1 dilution for testing unless otherwise indicated (10% concentration). A colony of New Zealand albino rabbits that have genetically good ears and free from mites were used. Three rabbits, weighing two to three kilograms, were used for each assay. Animals were housed singly in suspended cages and fed Purina Rabbit Chow and water ad libitum. Animals were maintained on a 12-hour light and 12-hour dark cycle. A dose of 1 ml of the test material was applied and spread once daily to the entire inner surface of once for five days per week for two weeks. The opposite untreated ear of each animal served as an untreated control.

The irritancy produced by repeated application of the chemical on the surface epidermis in the rabbit ear is evaluated on a scale of 0 to 5. The grades are summarized as follows:

0 = No irritation; 1 = few scales, no Erythema; 2 = diffuse scaling, no Erythema; 3 = Generalized scaling with Erythema; 4 = Scaling, Erythema and Edema; 5 = Epidermal necrosis and slough.

The test chemical falls under Grade 0 (no irritation observed).

Hence it can be concluded that the test chemical was not irritating to rabbit ears.

These results are further supported by a study performed to assess the irritation potential of the other test chemical in rabbits.

The test chemical was applied to rabbit skin and observed for signs of irritation (dose, duration not mentioned). The test chemical did not cause any irritation to rabbit skin. Hence, the test chemical can be considered not irritating to rabbit skin.

Based on the available data for the various test chemicals, it can be concluded that the test chemical can be considered to be not irritating to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.