Triethoxy(methyl)silane

Endpoint summary

Description of key information

Skin irritation (OCED TG 404): not 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:

16 Sep 1991 - 17 Feb 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

other: New Zealand hybrid albino

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Bancel, St Rambert D'Albon, FRANCE
- Age at study initiation: "adult"
- Weight at study initiation: 2.5±0.2 kg
- Housing: 1/cage; polystyrene cage with perforated flooring
- Diet: standard diet ad libitum
- Water: drinking water ad libitum
- Acclimation period: at least 1 wk

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20±3
- Humidity (%): 30-70
- Air changes (per hr): no details given
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: no details given

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 ml
- Concentration: neat

Duration of treatment / exposure:

4 h

Observation period:

1, 24, 48, 72 h. No further observation required.

Number of animals:

Six males

Details on study design:

TEST SITE
- Area of exposure: 6 cm²
- % coverage: not stated
- Type of wrap if used: 8 layer gauze pad, covered with perforated tape on crimped gauze bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): protocol states that excess test material should be wiped away with gauze moistened with distilled water if necessary. It is not clear if this was the case.
- Time after start of exposure: 4 h

SCORING SYSTEM: according to Draize scoring system

Irritation parameter:

erythema score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0.11

Max. score:

4

Reversibility:

fully reversible within: 48 h

Irritation parameter:

edema score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Irritant / corrosive response data:

See Table 1.

Other effects:

None reported.

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	Edema
	Max. score: 4	Max. score: 4
60 min	1/0/1/1/1/1	0/0/0/0/0/0
24 h	0/0/0/1/1/0	0/0/0/0/0/0
48 h	0/0/0/0/0/0	0/0/0/0/0/0
72 h	0/0/0/0/0/0	0/0/0/0/0/0
Average 24h, 48h, 72h	0.1	0
Reversibility*	c	-
time for reversion	48 h	-

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

 

Interpretation of results:

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

Conclusions:

A skin irritation study conducted in accordance with OECD 404 and GLP (reliability score 1), found triethoxy(methyl)silane to be transiently irritating to the skin of rabbits. The report describes the material as non irritant according to EC criteria; current EC criteria would concur with this finding.

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:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

It was not compliant with GLP and lacked a detailed description of materials and methods used.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

; limited details on housing, test animals and test substance identity reported

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: No data
- Weight at study initiation: No data
- Housing: No data
- Diet : Commerical diet was available ad libitum
- Water : Municipal water was available ad libitum
- Acclimation period: No data

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

IN-LIFE DATES: From: To: No data

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

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

Duration of treatment / exposure:

Single exposure, without washing. Potential duration of study 14 days - appears to have been terminated at 3 days, probably because no irritation was observed by this time point.

Observation period (in vivo):

Examined: 1, 6, 24, 48 and 72 h.

Number of animals or in vitro replicates:

6

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing : no washing reported

SCORING SYSTEM: Draize

TOOL USED TO ASSESS SCORE: fluorescein stain, no other details given

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Irritation parameter:

iris score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: reversibility: not applicable

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0.06

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

out of all 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Irritant / corrosive response data:

Minor transient eye irritation. See table 1.

Other effects:

None reported.

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	Cornea	Iris	Conjunctivae	Chemosis
	Max. score: 4	Max. score: 2	Max. score: 3	Max. score: 4
60 min	0/0/0/0/0/0	1/1/0/0/0/0	1/1/1/1/1/1	1/0/0/0/0/0
24 h	0/0/0/0/0/0	0/0/0/0/0/0	1/0/0/0/0/0	0/0/0/0/0/0
48 h	0/0/0/0/0/0	0/0/0/0/0/0	0/0/0/0/0/0	0/0/0/0/0/0
72 h	0/0/0/0/0/0	0/0/0/0/0/0	0/0/0/0/0/0	0/0/0/0/0/0
Average 24h, 48h, 72h	0	0	0.06	0
Reversibility*)	n/a	c	c	c
Average time for reversion	n/a	24 h	48 h	24 h

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

Discharge was reported in 2/6 at the 1- and 6-h observations.

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 that predates international guidelines and GLP (reliability score 2), only minor, transient eye irritation was observed following instillation of triethoxy(methyl)silane into the eyes of six rabbits. The Draize score of 0.06 (out of 13) would indicate that the test material would not be considered irritating to the eyes of rabbits.

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 sufficient quality for classification, labelling and risk assessment. Other available data are included as supporting studies.

 

A key skin irritation study, conducted in compliance with GLP and according to OECD TG 404, found triethoxy(methyl)silane to be a transient, mild irritant in rabbits. However, the results obtained in this study were not sufficient for classification of the registered substance as a skin irritant (Hazelton, 1992b). A limited report on skin irritation was also available, which was not conducted according to guideline or in compliance with GLP (reliability score 4) for the registered substance. The application of the undiluted test material on rabbit skin did not result in any irritation (BRRC, 1981d). The results of both experiments are in agreement with the lack of skin irritation potential of triethoxy(methyl)silane.

 

The key study for eye irritation which was not in compliance with GLP, but was equivalent or similar to OECD TG 405, showed that triethoxy(methyl)silane was not irritating to rabbit eyes. Only minor, transient eye irritation was observed following instillation of the test material into the eyes of six rabbits. The Draize score of 0.06 out of 13 indicates the registered substance would not be considered irritating to the eyes of rabbits ( Bushy Run Research Center, 1981).

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) 1272/2008 and are therefore conclusive but not sufficient for classification.