Triethoxypropylsilane

Endpoint summary

Description of key information

Skin irritation (OCED TG 404): irritating
Eye irritation (OECD TG 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:

13.02.1992 to 24.04.1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

occluded dressing

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, Halle-Kűnsebeck, GERMANY
- Age at study initiation: 5-7 months
- Weight at study initiation: Males: 2.10, 2.27 kg; Females: 2.31 kg
- Housing: 1/ stainless steel cage
- Diet: standard diet ad libitum
- Water: drinking water ad libitum
- Acclimation period: 1 day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22.5
- Humidity (%): 50-60
- Air changes (per hr): not given
- Photoperiod (hrs dark / hrs light): 12 /12

IN-LIFE DATES: From: 1992-02-25 (stated) To: 1992-02- 11 (estimated)

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
- Concentration: neat

Duration of treatment / exposure:

4 h

Observation period:

Observed at 1, 24, 48 and 72 h, and daily until day 14. Data are reported only for days 4, 7, 10 and 14.

Number of animals:

3 (2 male, 1 female)

Details on study design:

TEST SITE
- Area of exposure: 6.25 cm²
- % coverage: not stated
- Type of wrap if used: 3-ply patch: cellulose gauze, artificial wool coated with natural rubber, "synthetic film glue"; wrap: "acrylastic" bandage

REMOVAL OF TEST SUBSTANCE
- Washing: washed off gently
- Time after start of exposure: 4 h

SCORING SYSTEM: as given in OECD 404. Grading according to Gilman et al. 1983.

Irritation parameter:

erythema score

Basis:

other: mean out of animals #1 and #2

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: in animal #1 a brownish discolouration of the treated site was observed up to 5 days post-application

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 10 days

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 10 days

Irritant / corrosive response data:

All three animals formed skin scales 6-7 days after treatment. The scales peeled off 1-2 days afterwards. See table 1 for detail.

Other effects:

None. The general condition of the test animals was not affected.

Table 1: Irritant/corrosive response data for each animal at each observation time up to removal of each animal from the test

Score at time point / Reversibility	Erythema & eschar	Edema
	Max. score: 4	Max. score: 4
1 h	2/2/2	4/3/3
24 h	3/3/2	3/2/1
48 h	3/3/2	2/2/1
72 h	3/3/2	2/1/1
Day 4	3/3/2	2/1/1
Day 7	1/1/1	0/1/1
Day 10	1/0/1	0/0/0
Day 14	0/-/0	0/-/0
Mean 24, 48, 72 h	3/3/2	2.3/1.7/1
Mean 1, 24, 48, 72 h; 3 animals	2.5	2.08
Reversibility*	c	c
Average time for reversion	Day 14	Day 10

* Reversibility: c. = completely reversible; n.c. = not completely reversible; n. = not reversible

PII= 4.6; graded moderately irritant (Gilman et al.1983)

erythema/eschar >=2.3 in 2 of 3 animals; category 2 irritant according to EC criteria

 

Interpretation of results:

other: Category 2 based on CLP criteria (EU criteria according to Regulation (EC) No. 1272/2008)

Conclusions:

In a skin irritation study conducted largely in accordance with OECD 404 and to GLP (reliability score 1) but using an occlusive dressing, found triethoxypropylsilane to be moderately irritating to the skin of rabbits. Current EC criteria would concur with the findings of this study (as conducted), although it is possible that the use of a semi-occlusive dressing might reduce the irritation observed.

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:

28.02.1992 to 21.07.1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

animal husbandry - minor excursions from recommended relative humidity

GLP compliance:

yes

Species:

rabbit

Strain:

other: White Russian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: ASTA Medica AG, Halle-Kűnsebeck, GERMANY
- Age at study initiation: Males: 8 or 12 months; Females: 6 months
- Weight at study initiation: Males: 2.47, 2.49 kg; Females: 2.33 kg
- Housing: 1/ cage. Stainless steel cage with grating floor.
- Diet: standard diet approximately 120 g/day
- Water: drinking water ad libitum
- Acclimation period: at least 1 day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22 (briefly to 22.5)
- Humidity (%): 50-70 (briefly to 74). The Guideline recommends a maximum of 70%.
- Air changes (per hr): not stated
- Photoperiod (hrs dark / hrs light): 12 /12

IN-LIFE DATES: From: 10 March 1992 to 20 March 1992

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.1 mL (neat)

Duration of treatment / exposure:

Single application without washing; study terminated for last animal after 6 days.

Observation period (in vivo):

1, 24, 48, 72 hours, then daily to day 4 (2 animals) or 6 (1 animal).

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing : no washing

SCORING SYSTEM: Draize

TOOL USED TO ASSESS SCORE: pencil light

Irritation parameter:

cornea opacity score

Basis:

other: mean out of all 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritation parameter:

iris score

Basis:

other: mean out of all 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: reversibility not applicable.

Irritation parameter:

conjunctivae score

Basis:

other: mean out of animal #2 and #3

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 4 days

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.7

Max. score:

3

Reversibility:

fully reversible within: 4 days

Irritation parameter:

chemosis score

Basis:

other: mean out of all 3 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Irritant / corrosive response data:

The test material was transiently irritant, see table 1.
Scored at 24, 48 and 72 h it was clear that 2 of 3 animals did not achieve scores that would be indicative of irritation.

Other effects:

There were no systemic effects.

Table 1: Irritant/corrosive response data for each animal at each observation time

Score at time point / Reversibility	Cornea	Iris	Conjunctivae - redness	Conjunctivae- chemosis	Conjunctivae - discharge
	Max. score: 4	Max. score: 2	Max. score: 3	Max. score: 4	Max. score 3
60 min	0/0/0	1/0/0	3/1/2	3/1/1	3/3/3
24 h	0/0/0	0/0/0	2/1/1	1/0/0	1/0/0
48 h	0/0/0	0/0/0	2/1/1	0/0/0	0/0/0
72 h	0/0/0	0/0/0	1/1/0	0/0/0	0/0/0
Average 24 h, 48 h, 72 h	0/0/0	0/0/0	1.7/1/0.7	0.3/0/0	0.3/0/0
Average score (including area affected, max 110)*	0	0.4	5.3
Reversibility**	n/a	c	c	c	c
Maximum time for reversion	n/a	24 h	6 days***	48 h	48 h

* Scoring ocular lesions: as given in report, based on 1, 24, 48, 72 h

** Reversibility: c. = completely reversible; n.c. = not completely reversible; n. = not reversible

*** Conjunctival redness was still evident in one animal at day 4.

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 conducted according to OECD 405 and in compliance with GLP (reliability score 1), triethoxypropylsilane was transiently irritating, with a Draize score of 6 out of 110, and it was therefore concluded that the test substance is not irritating to the eyes.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Studies were chosen as key when the available study was of relevance and of sufficient quality for classification, labelling and for risk assessment

The key data are the only irritation data available for this substance; both studies have been assigned a reliability score of 1. However, these results are the same as those for the structurally-related trimethoxypropylsilane (CAS: 1067-25-0), which was also irritating to the skin, but not the eyes.

In a key skin irritation study conducted largely in accordance with OECD TG 404 and in compliance with GLP (ASTA Medica, 1992b) but using an occlusive dressing, found triethoxypropylsilane to be moderately irritating to the skin of rabbits. It is possible that the use of a semi-occlusive dressing might reduce the irritation observed.

In a key eye irritation study conducted according to OECD TG 405 and in compliance with GLP (ASTA Medica, 1992c), triethoxypropylsilane was only transiently irritating, with a Draize score of 6 out of 110, and it was therefore concluded that the test substance is not irritating to the eyes.

Justification for classification or non-classification

Based on the available in vivo data, triethoxypropylsilane is not classified for eye irritation under Regulation (EC) 1272/2008/EC.

Regarding skin irritation, the registered substance is classififed as 'Skin Irritant Category 2', with the hazard statement 'H315: Causes skin irritation'.