Trimethoxyoctadecylsilane

Endpoint summary

Description of key information

Skin irritation (OECD 404), rabbit: not irritating
Eye irritation (OECD 405), rabbit): not irritating 

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 Sep - 01 Oct 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Version / remarks:

1998

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Covance Research Products, Inc., Denver, PA, USA
- Age at study initiation: young adults
- Weight at study initiation: 2750 – 2981 g
- Housing: animals were caged in individually suspended wire-mesh cages
- Diet: PMI Nutrition International, Inc. certified rabbit LabDiet 5322, approximately 150 g per day during the study
- Water: tap water, ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.4 – 20.0
- Humidity (%): 50 - 59
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

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

Duration of treatment / exposure:

4 h

Observation period:

3 days
Reading time points: 30 - 60 min, 24, 48 and 72 h

Number of animals:

2 males and 1 female

Details on study design:

TEST SITE
- Area of exposure: 6.25 cm² of clipped skin of the back and flanks
- Type of wrap if used: a piece of two-ply gauze patch was placed over the treatment area and secured in place with Micropore tape. The patches were overwrapped with a gauze binder and secured with Dermiform tape. Plastic restraint collars were applied to the animals to prevent ingestion of the test article and/or bandages.

REMOVAL OF TEST SUBSTANCE
- Washing: Residual test material was removed with disposable paper towels moistened with deionized water.
- Time after start of exposure: 4 h

SCORING SYSTEM
- Draize scoring system

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No mortalities occurred during the study period. The test article induced very slight erythema (grade 1) on one animal 30 – 60 min post-application. There was no edema, nor were there any other dermal findings. Based on the results of the study the test item should be considered as non-irritant.

Other effects:

There were no remarkable body weight changes during the study period.

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008

Conclusions:

Treatment of 3 New Zealand White rabbits under semi-occlusive conditions with 0.5 ml undiluted test substance induced very slight erythema (grade 1) on one animal 30 – 60 min post-application but being fully reversible within 24 h. There was no edema, nor were there any other dermal findings. Based on the results of the study the test item should be considered as non-irritant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 Nov - 24 Nov 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981

Deviations:

yes

Remarks:

No data for analytical purity is reported.

GLP compliance:

yes

Species:

rabbit

Strain:

other: White Russian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Asta-Werke AG, Bielefeld, Germany
- Age at study initiation: 6 months
- Weight at study initiation: 2400 – 2700 g
- Housing: animals were caged individually in stainless-steel cages
- Diet: maintenance diet for rabbits (ssniff Spezialfutter GmbH, Soest, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 1 day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 23
- Humidity (%): 45 - 60
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated contralateral eye served as control

Amount / concentration applied:

TEST MATERIAL
Amount applied: 0.1 ml

Duration of treatment / exposure:

single application without rinsing

Observation period (in vivo):

7 days
Reading time points: 1, 24, 48 and 72 h and daily up to 7 days

Number of animals or in vitro replicates:

2 males and 1 female

Details on study design:

SCORING SYSTEM: Draize scoring system

TOOL USED TO ASSESS SCORE: Cliptrix fluorescent marker

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.33

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.67

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

One hour post exposure, effects on conjunctivae redness (grade 3, 3/3 animals) were observed. Mean values over 24, 48 and 72 h for conjunctivae redness were 1.33, 1.67 and 1, respectively. Any effects observed were fully reversed at the end of the observation period.

Table 1: Summary of eye irritation parameters

Rabbit #	Time [h]	conjunctivae		iris	cornea
		redness	swelling
1	1	3	0	0	0
	24	2	0	0	0
	48	2	0	0	0
	72	0	0	0	0
	average	1.33	0	0	0
2	1	3	0	0	0
	24	2	0	0	0
	48	2	0	0	0
	72	1	0	0	0
	average	1.67	0	0	0
3	1	3	0	0	0
	24	1	0	0	0
	48	1	0	0	0
	72	1	0	0	0
	average	1	0	0	0

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008

Conclusions:

In an eye irritation study performed according to OECD 405 the substance was found to be not irritating to eyes. Treatment of 3 White Russian rabbits with 0.1 ml test substance resulted in no effects on cornea and iris in any animal at any time point. No chemosis was observed in any animal. One hour post exposure, effects on conjunctivae redness (grade 3, 3/3 animals) were observed. Mean values over 24, 48 and 72 h for conjunctivae redness were 1.33, 1.67 and 1, respectively. Any effects observed were fully reversed at the end of the observation period. Based on the results of the study the test item is considered as non-irritant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion

Two skin irritation studies with Trimethoxyoctadecylsilane (CAS 3069-42-9) are available.

In a key skin irritation study performed according to OECD 404 and in compliance with GLP one female and two male New Zealand White rabbits were exposed to 0.5 ml of the neat test material for 4 hours applied onto the clipped skin via semi-occlusive dressing (WIL, 2001). Skin reactions were graded according to the Draize Scoring system 1, 24, 48 and 72 hours post-application. No mortalities occurred and no remarkable body weight changes were observed during the study period. The test article induced very slight erythema (grade 1) in 1/3 animals 30 – 60 min post-application, which was fully reversible within 24 h. There was no edema, nor were there any other dermal findings.

In a supporting skin irritation study performed according to OECD 404 and in compliance with GLP three female White Russian rabbits were exposed to 0.5 ml of the neat test material for 4 hours applied onto the shaved skin via occlusive dressing (Asta-Werke, 1986). Skin reactions were graded according to the Draize scoring system 1, 24, 48 and 72 hours post-application. No mortalities occurred and no remarkable body weight changes were observed during the study period. Neither erythema nor edema formation were observed during the study period.

Based on the above study results the test item should be considered as not-irritating to the skin.

 

Eye irritation/corrosion

An eye irritation study performed according to OECD 405 and in compliance with GLP with Trimethoxyoctadecylsilane (CAS 3069-42-9) is available (Asta-Werke, 1986c). For the assessment of the eye irritation properties 0.1 ml of the test substance was instilled in the eye of one female and two male White Russian rabbits. The eyes were examined and the changes were graded according to the Draize scoring system 1, 24, 48 and 72 hours and daily up to 7 days post-application. One hour post exposure, effects on conjunctivae redness (grade 3, 3/3 animals) were observed. Mean values over 24, 48 and 72 h for conjunctivae redness were 1.33, 1.67 and 1, respectively. Any effects observed had fully reversed at the end of the observation period. Neither iridial irritation nor corneal opacity and chemosis were observed in any animal during the course of the study. No remarkable body weight changes were noted during the study period. Based on the result of the study the test substance is considered not to be irritating to eyes.

Justification for classification or non-classification

The available data on skin and eye irritation of the registered substance do not meet the criteria for classification according to Regulation (EC) No 1272/2008, and are therefore conclusive but not sufficient for classification.