Triethoxyoctylsilane

Endpoint summary

Description of key information

In a skin irritation study conducted according to OECD Test Guideline 404 and in compliance with GLP (ASTA Medica AG, 1992b), triethoxy(octyl)silane was irritating to the skin of rabbits. Irritation had completely reversed by day 10. There were no systemic effects.  

In an eye irritation study conducted according to OECD Test Guideline 405 and in compliance with GLP (ASTA Medica AG, 1992c), triethoxy(octyl)silane was not irritating to the eyes of rabbits. There were no systemic effects.

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:

22.04.1992 to 15.05.1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Species:

rabbit

Strain:

other: White russian

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: ASTA Medica AG, D-4802 Halle-Künsebeck
- Age at study initiation: Nine months
- Weight at study initiation: Males: 2.49 and 2.52 kg; Female: 2.76 kg
- Housing: Individually in stainless steel cages
- Diet: 120 g/day/animal
- Water: Ad libitum
- Acclimation period: At least one day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-21
- Humidity (%): 42-70
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 27.04.1992 To: 15.05.1992

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

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

Duration of treatment / exposure:

Four hours

Observation period:

9/10 days after application (at 1, 24, 48 and 72 hours, then daily)

Number of animals:

Three

Details on study design:

TEST SITE
- Area of exposure: Dorsal area between shoulder and sacrum
- % coverage: No data, but was 6.25 cm2
- Type of wrap if used: Occlusive (patch made of the following layers: cellulose gauze, cellulose fabric coated with natural rubber, synthetic film glue; a bandage was then wrapped several times around the trunk to provide complete occlusion).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: Four hours

SCORING SYSTEM: Gilman et al (1983) Relationship between the primary dermal irritation index and ocular irritation. J. Toxicol.-Cut. & Ocular Toxicol. 2, 107-117.

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 1, 24, 48, 72 hours

Score:

5.1

Max. score:

8

Reversibility:

fully reversible within: 10 days

Remarks on result:

other: Mean scores for erythema for 24, 48 and 72 hours were at least 2.3 in all animals. The mean scores for edema for 24, 48 and 72 hours were at least 2.3 in 2/3 animals.

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 10 days

Remarks on result:

positive indication of irritation

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 9 days

Remarks on result:

positive indication of irritation

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 10 days

Remarks on result:

positive indication of irritation

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 9 days

Remarks on result:

positive indication of irritation

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 9 days

Remarks on result:

positive indication of irritation

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 10 days

Remarks on result:

positive indication of irritation

Irritant / corrosive response data:

Table 1. Severe changes were noted in the animals. Erythema occurred in all three animals. In 2/3 animals there was moderate to severe (grade 3) erythema at one hour. At this time the erythema in the third animal was well-defined (grade 2), then at 24 hours it was moderate to severe (grade 3). These findings had completely disappeared by day 10 of the observation period. In addition, skin scales, which immediately peeled off, were observed in all three animals from day 7 onwards.

A moderate oedema (grade 3) was noted in two animals after one hour of patch removal. The edema was severe in the third animal (grade 4). These findings had reversed by day 10.

Other effects:

Systemic effects did not occur in any animals.

Table 1 Summary of skin irritation scores

Skin reaction	Hours/days after exposure	Animal 1 scores	Animal 2  scores	Animal 3 scores
Erythema and eschar	1 hr	2	3	3
	24 hr	3	3	3
	48 hr	3	2	2
	72 hr	3	2	2
	4 d	3	2	2
	7 d	2	2	3
	9 d	1	0	1
	10 d	0		0
Edema	1 hr	3	3	4
	24 hr	3	3	3
	48 hr	2	2	2
	72 hr	2	2	1
	4 d	2	2	1
	7 d	1	2	2
	9 d	0	0	1
	10 d	0		0

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

In an occlusive skin irritation study conducted according to OECD 404 and in compliance with GLP (reliability score 1) triethoxyoctylsilane was irritating to the skin of rabbits. Irritation had completely reversed by day 10. There were no systemic effects.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (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:

05.05.1992 to 21.05.1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

yes

Species:

rabbit

Strain:

other: white russian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: ASTA Medica AG, D-4802 Halle-Künsebeck
- Age at study initiation: 8-10 months
- Weight at study initiation: Males: 2.58 kg; Females: 2.39 and 2.58 kg
- Housing: Individually in stainless steel cages
- Diet: Approx. 120 g/day/animal
- Water: Ad libitum
- Acclimation period: At least one day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5-20.0
- Humidity (%): 50-70
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 11.05.1992 To: 21.05.1992

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml

Duration of treatment / exposure:

No rinsing

Observation period (in vivo):

Three days (including 1, 24, 48, 72 hours)

Number of animals or in vitro replicates:

Three

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No

SCORING SYSTEM: Draize

TOOL USED TO ASSESS SCORE: Cliptrix pencil light

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 1, 24, 48 and 72 hours

Score:

2

Max. score:

110

Reversibility:

fully reversible

Remarks on result:

other: The eye irritation did not meet EU classification criteria.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 hours

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 hours

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 hours

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis 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:

Table 1. There were no changes to the cornea or iris. The conjunctiva of all three animals reacted with diffuse redness (grade 2). The finding had completely disappeared 48 hours after application. Slight swelling (grade 1) occurred in all three animals only one hour after application. In addition, discharge moistened lids and hair just adjacent to lids in one animal was observed one hour after application.

Other effects:

There were no systemic toxic effects in any of the animals.

Table 1 Summary of irritation scores

Reaction	Day/hours after exposure	Scores for each animal
		Animal 1	Animal 2	Animal 3
Corneal opacity	1 h	0	0	0
	24 h	0	0	0
	48 h	0	0	0
	72 h	0	0	0
Area of cornea involved	1 h	0	0	0
	24 h	0	0	0
	48 h	0	0	0
	72 h	0	0	0
Iris	1 h	0	0	0
	24 h	0	0	0
	48 h	0	0	0
	72 h	0	0	0
Conjunctival redness	1 h	2	2	2
	24 h	1	1	1
	48 h	0	0	0
	72 h	0	0	0
Conjunctival Chemosis	1 h	1	1	1
	24 h	0	0	0
	48 h	0	0	0
	72 h	0	0	0
Discharge	1 h	0	0	2
	24 h	0	0	0
	48 h	0	0	0
	72 h	0	0	0

Interpretation of results:

GHS criteria not met

Conclusions:

In an eye irritation study conducted according to OECD 405 and in compliance with GLP (reliability score 1) triethoxy(octyl)silane was not irritating to the eyes of rabbits. There were no systemic effects.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There are two skin irritation studies with a reliability score of 1, both conducted in 1992. The key study was selected because it had a longer post-exposure period and demonstrated reversibility of the irritation, and therefore more closely met the current guideline. The second reliability score 1 study also showed the test substance to be irritating to the skin of rabbits, based on the presence of desquamation at the end of the observation period.

There are also two eye irritation studies with a reliability score of 1, both conducted in 1992. The key study was selected as it had a longer observation period. However, all three available studies showed that the test substance is not irritating to the eyes .

Justification for classification or non-classification

Based on the key data, triethoxy(octyl)silane is not classified for eye irritation according to Regulation (EC) No 1272/2008. Regarding skin irritation, this substance is classified as Skin Irrit. Cat. 2 with the hazard statement 'H315: Causes skin irritation'.