Ethoxytrimethylsilane

Endpoint summary

Description of key information

skin irritation (OECD 404): not irritating
eye irritation (OECD 405): 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:

07 - 17 May 2002

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:

adopted July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Freie und Hansestadt Hamburg, Behörde für Arbeit, Gesundheit uns Soziales, Germany

Species:

rabbit

Strain:

Himalayan

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: LPT, Laboratory of Pharmacology and Toxicology KG, Loehndorf, Germany
- Age at study initiation: approximately 4.5 and 5.5 months
- Weight at study initiation: 2.1-2.3 kg
- Fasting period before study: no
- Housing: Single housing before and after the exposure period. During exposure the animals were kept singly in restrainers, which allowed free movement of the head but prevented a complete body turn.
- Diet: ssniff K-H (ssniff Spezialdiäten GmbH, Soest, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20±3
- Humidity (%): 55±15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 17 June 2002 To: 22 Aug 2002

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated skin site served as control

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 mL

Duration of treatment / exposure:

4 h

Observation period:

72 h
Reading time points: 24, 48 and 72 h

Number of animals:

3 males

Details on study design:

TEST SITE
- Area of exposure: approximately 6 cm²
- Type of wrap if used: Test site covered with a gauze patch, which was held in contact to the skin by means of a semi-occlusive dressing (non-irritating tape).

REMOVAL OF TEST SUBSTANCE
No residual test substance was removed.

SCORING SYSTEM: Draize scoring system

Irritation parameter:

erythema score

Basis:

mean

Remarks:

out of all 3 animals

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Irritation parameter:

edema score

Basis:

mean

Remarks:

out of all 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritant / corrosive response data:

Erythema grade 1 (3/3 animals) were observed 60 min and 24 h after patch removal. Erythema reactions were fully reversible within 48 h. No oedema reactions were observed in any animal. No other findings were observed.

Table 1: Individual results of the skin irritation test.

Rabbit No.	1		2		3
Observation time	Erythema	Edema	Erythema	Edema	Erythema	Edema
1 h	1	0	1	0	1	0
24 h	1	0	1	0	1	0
48 h	0	0	0	0	0	0
72 h	0	0	0	0	0	0
Mean value	0.33	0	0.33	0	0.33	0
24 + 48 + 72 h

Interpretation of results:

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

Conclusions:

In a skin irritation study with ethoxy(trimethyl)silane (according to OECD 404, GLP compliant) the substance was found to be not irritating. Treatment of 3 male Himalayan rabbits under semi-occlusive conditions with 0.5 mL undiluted test substance only provoked slight erythema reactions being fully reversible within 48 h. Mean erythema and oedema scores over 24, 48, and 72 h were 0.33 and 0, respectively.

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:

07 - 19 May 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

adopted Feb 1987

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Freie und Hansestadt Hamburg, Behörde für Arbeit, Gesundheit uns Soziales, Germany

Species:

rabbit

Strain:

Himalayan

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: LPT, Laboratory of Pharmacology and Toxicology KG, Loehndorf, Germany
- Age at study initiation: approximately 11 months
- Weight at study initiation: 2.3-2.6 kg
- Fasting period before study: no
- Housing: Single housing before and after the exposure period. For 8 h following the test substance application the animals were kept singly in restrainers, which allowed free movement of the head but prevented a complete body turn, wiping of the eyes with the paws and excluded irritation of the eye by excrements and urine.
- Diet: ssniff K-H (ssniff Spezialdiäten GmbH, Soest, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20±3
- Humidity (%): 55± 15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated left 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):

72 h
Reading time points: 24, 48 and 72 h

Number of animals or in vitro replicates:

3 males

Details on study design:

SCORING SYSTEM: Draize scoring system

TOOL USED TO ASSESS SCORE: hand-slit lamp / fluorescein

The test substance was placed in the conjunctival sac of the right eye of each animal after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second in order to prevent loss of the material. The eyes were examined ophthalmoscopically with a slit lamp prior to the administration and 1, 24, 48, and 72 hours after the administration. 24 h after administration the eyes were treated additionally with fluorescein and examined.

Irritation parameter:

cornea opacity score

Basis:

other: mean of 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

iris score

Basis:

other: mean of 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: not applicable

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

3

Reversibility:

other: not applicable

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Irritant / corrosive response data:

No effects on cornea and iris were observed in any animal. After 1 h redness (grade 1) was observed in all 3/3 animals and was fully reversible within 48 h. After 1 h chemosis grade 1 (1/3) and grade 2 (2/3) was observed and was fully reversible within 48 h. No other findings were reported.

Other effects:

No systemic intolerance reactions were observed.

Table 1: Individual results of the eye irritation study in rabbits.

Rabbit #	Time [h]	conjunctivae		iris	cornea
		redness	swelling
1	1	1	1	0	0
	24	0	0	0	0
	48	0	0	0	0
	72	0	0	0	0
	average	0	0	0	0
2	1	1	2	0	0
	24	1	1	0	0
	48	0	0	0	0
	72	0	0	0	0
	average	0.33	0.33	0	0
3	1	1	2	0	0
	24	1	1	0	0
	48	0	0	0	0
	72	0	0	0	0
	average	0.33	0.33	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 with ethoxy(trimethyl)silane (according to OECD 405, GLP compliant) the substance was found to be not irritating. Treatment of 3 male Himalayan rabbits with 0.1 mL undiluted test substance only provoked slight redness and chemosis being fully reversible within 48 h. No effects on iris and cornea were observed. Mean conjunctivae and chemosis scores over 24, 48, and 72 h were 0, 0.33, 0.33 and 0, 0.33, 0.33, respectively, for the individual animals.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

A skin irritation test is available with ethoxy(trimethyl)silane (CAS 1825-62-3), which was performed in Himalayan rabbits according to OECD 404 and in compliance with GLP (LPT, 2002). Neat test substance (0.5 mL) was applied to a 6 cm² application site (shaved) for 4 h under semi-occlusive conditions. No residual test substance was removed. Sixty minutes and 24, 48, 72 h after patch removal the application site was examined. Erythema (grade 1) was observed in all 3 animals at 60 min and 24 h after patch removal, but was fully reversible within 48 h. No oedema reactions or other findings were reported. Erythema and oedema mean values over 24, 48, and 72 h were 0.33 and 0, respectively. In conclusion, ethoxy(trimethyl)silane was not irritating to the skin under the conditions of the test.

Eye

An eye irritation test is available with ethoxy(trimethyl)silane (CAS 1825-62-3), which was performed in Himalayan rabbits according to OECD 405 and in compliance with GLP (LPT, 2002). Neat test substance (0.1 mL) was instilled into the eye of 3 male animals. The test substance was placed in the conjunctival sac of the right eye of each animal after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second in order to prevent loss of the material. The eyes were examined ophthalmoscopically with a slit lamp prior to the administration of the test material and 1, 24, 48, and 72 hours after the administration of the test material. 24 h after administration the eyes were treated additionally with fluorescein and examined. No rinsing was performed. No effects on cornea and iris were observed in any animal at any reading time point. After 1 h redness (grade 1) was observed in all 3/3 animals and was fully reversible within 48 h. After 1 h chemosis grade 1 (1/3) and grade 2 (2/3) was observed and was fully reversible within 48 h. No other findings were reported. The mean values over 24, 48, and 72 h for redness and chemosis were 0, 0.33, and 0.33, each for animal 1, 2, and 3, respectively. In conclusion, ethoxy(trimethyl)silane was not irritating to the eye under the conditions of the test.

Justification for classification or non-classification

The available data on skin and eye irritation/corrosion of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.