Methyl-tris acetonoximo-silane

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-11-15 to 2004-12-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

adopted 24 April 2002

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

A mixture of: propan-2-one-O,O'-(methoxymethylsilandiyl)dioxime; propan-2-one-O-(dimethoxymethylsilyl)oxime; propan-2-one-O,O',O''-(methylsilantriyl)trioxime

EC Number:

460-110-3

EC Name:

A mixture of: propan-2-one-O,O'-(methoxymethylsilandiyl)dioxime; propan-2-one-O-(dimethoxymethylsilyl)oxime; propan-2-one-O,O',O''-(methylsilantriyl)trioxime

IUPAC Name:

A mixture of: propan-2-one-O,O'-(methoxymethylsilandiyl)dioxime; propan-2-one-O-(dimethoxymethylsilyl)oxime; propan-2-one-O,O',O''-(methylsilantriyl)trioxime

Specific details on test material used for the study:

- Name: "WASOX-MMAC2"
- Batch No.: 1000024854
- Purity: The test substance is a mixture of mainly 3 components:
MMAC2 (range: 45-80% w/w), accurately 55.0% (GC-% w/w),
MM2AC (range 2-30% w/w), accurately 11.7% (GC-% w/w) and
MAC3 (range 5-30% w/w),accurately 24.0% (GC-% w/w) plus by-products and impurities.
The 3 components act uniformly as hardeners for silicone sealing masses. They polymerise, triggered bv hydrolysis.
- CAS No. (main component): 72122-57-7
- Solubility in water: Poorly soluble. A polymeric, insoluble in water, is formed by hydrolysis. Rapid onset of hydrolysis.
- Solubility in other solvents: Easily soluble in toluene and methylcyclohexane
- Appearance: Solid and liquid parts at room temperature.Yellowish brownish colour.
- Melting point: 30 - 35 °C.
- Conditions of storage: Storage under a nitrogen atmosphere, as the substance reacts with water, even from air humidity. Ambient temperature (theoretically up to approx. 40 °C possible), protected against light (handling without protection against light is acceptable).
- Handling precautions: Exothermic reaction with water or humidity from the air.
- Date of expiry: December 2005

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH, 97633 Sulzfeld, Germany
- Weight at study initiation: Animal No. 1: 1.8 kg, Animal No. 2: 2.1 kg and Animal No. 3: 2.1 kg
- Housing: Individual caging in metal wire cages
- Diet (e.g. ad libitum): Yes, Altromin 2123 maintenance diet for rabbits
- Water (e.g. ad libitum): Yes, tap water
- Acclimation period: 5 days (animal No. 1) and 12 days (animals Nos. 2 and 3)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Average of 19.2
- Humidity (%): Average of 50.1
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL

Duration of treatment / exposure:

The first patch was removed after 3 minutes. As there was no serious skin reaction observed, a second patch was applied at a different site and removed after 1 hour. Because there was still no serious skin reaction noted, a third patch was applied and removed after 4 hours.

Observation period:

1, 24, 48 and 72 hours after patch removal

Number of animals:

3 animals

Details on study design:

TEST SITE
- Area of exposure: 2.5 cm x 2.5 cm, the test sites were meian on the dorsal thoracal region
- Type of wrap if used: the cellular patches with the test item were held in place by fixing them marginally with non-irritating tapes. The application sites were covered semiocclusively by a dressing. Access by the animals to the application sites was prevented by a plastic collar.

Test Procedure:
Initial test:
First the test substance was administered to one animal in a sequential manner. Three patches, each 0.5 mL of the test substance, were applied sequentially to the animal. The first patch was removed after 3 minutes. As there was no seious skin reaction observed, a second patch was applied at a different site and removed after one hour. Because there was still no serious skin reaction noted, a third patch was applied and removed after 4 hours.

Confirmatory Test:
As no corrosive effect was observed in the initial test, the test substance was adminsitered to two additional animals, each with one patch, one week later for an exposure period of 4 hours.

Skin examinations:
The skins of the animals were examined for local alterations one day before the administration of the test substance (after clipping of the hair) and immediately before the administration. The treated areas of the animals were examined for erythema/eschar and oedema as well as for other local alterations (such as hyperplasia, scaling, discolouration, fissues, scabs and alopecia) approximately 1, 24, 48 and 72 hours after patch removal.
No further examinations were performed thereafter. The 3 minutes, 1 hour and 4 exposure sites of the first animal were examined immediately after the end of the exposure time. No further examinations were performed thereafter for the 3 minutes and 1 hour test sites. The skin was examined using a cold light source KL 1500 electronic.

The following scoring scheme were applied:

Erythema and eschar formation:
0 - No erythema
1 - Very slight erythema (barely perceptible)
2 - Well-defined erythema
3 - Moderate to severe erythema
4 - Severe erythema (beet redness) to slight eschar formation (injuries in depth)

Oedema formation:
0 - No oedema
1 - Very slight oedema (barely perceptible)
2 - Slight oedema (edges of area well-defined by definite raising)
3 - Moderate oedema (raised approximately 1 millimetre)
4 - Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

All areas to be treated with the test substance and alt contral areas were normal before the application and at each observation time. Moreover, no symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results from a primary dermal irritation study conducted according to OECD guideline 404, the test item WASOX-MMAC2 can be considered as non-irritant to the skin.

Executive summary:

In a primary dermal irritation study conducted according to OECD guideline 404, 0.5 mL of the test item was applied to three New Zealand White rabbits for 4 hours under semi-occlusive conditions to a body surface area of 2.5 cm². Skin reactions were scored approximately 1, 24, 48 and 72 hours after patch removal. The test item did not cause any skin effects and is considered under the conditions of this study as nontoxic.