Dicyclopentyldimethoxysilane

Endpoint summary

Description of key information

In a skin irritation study conducted according to OECD Test Guideline 404 and in compliance with GLP, dicyclopentyl(dimethoxy)silane (CAS 126990-35-0) was irritating to the skin of rabbits under semiocclusive conditions, based on well-defined erythema with desquamation in all three animals tested, and moderate edema in two of the three animals tested (Safepharm Laboratories Ltd, 1995c).

In an eye irritation study conducted according to OECD Test Guideline 405 and in compliance with GLP, dicyclopentyl(dimethoxy)silane was not irritating to the eyes of rabbits (Safepharm Laboratories Ltd, 1995d).

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:

30.06.1995 to 14.07.1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: David Percival Ltd, UK
- Age at study initiation: 12-16 weeks
- Weight at study initiation: 2.39-2.6 kg
- Housing: Individually in suspended metal cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-24
- Humidity (%): 49-74
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 30.06.1995 to 14.07.1995

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

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

Duration of treatment / exposure:

4 hours

Observation period:

14 days

Number of animals:

3 male

Details on study design:

TEST SITE
- Area of exposure: Dorsal flank
- % coverage: Not specified
- Type of wrap if used: Semi-occlusive

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

SCORING SYSTEM: Draize

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

24/48/72 h

Score:

4.8

Max. score:

8

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Crust formation and desquamation on Days 7 and 14, respectively.

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: Crust formation and desquamation on Days 7 and 14, respectively.

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: Crust formation and desquamation on Days 7 and 14, respectively.

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

Well-defined erythema and slight to moderate oedema was noted at all treated skin sites one hour after patch removal and at the 24, 48 and 72 hour observations. The erythema extended up to 4cm beyond two treatment sites one hour after patch removal. The erythema extended up to 9cm beyond all treatment sites at the 24, 48 and 72 hour observations.

Other effects:

Crust formation was noted at all treated skin sites at the 7 day observation, which prevented the accurate evaluation of erythema at one treated skin site at this time. Desquamation was noted at all treated skin sites 14 days after treatment.

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

In a skin irritation study conducted according to OECD Test Guideline 404 and in compliance with GLP, dicyclopentyl(dimethoxy)silane was irritating to the skin of rabbits under semiocclusive conditions based on well-defined erythema and desquamation in all three animals tested, and moderate edema in two of the three animals tested.

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:

05.07.1995 to 12.07.1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Qualifier:

according to guideline

Guideline:

other: 92/69/EEC, Method B5

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: David Percival Ltd.
- Age at study initiation: 12-16 weeks
- Weight at study initiation: 2.7-2.85 kg
- Housing: Individually in suspended metal cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Minimum five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-23
- Humidity (%): 49-74
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 05.07.1995 To: 12.07.1995

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:

Not applicable

Observation period (in vivo):

Seven days

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: standard ophthalmoscope

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.3

Max. score:

3

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.3

Max. score:

3

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

3

Reversibility:

fully reversible

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.3

Max. score:

2

Reversibility:

fully reversible

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

fully reversible

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

fully reversible

Irritant / corrosive response data:

No corneal effects. Iridial inflammation was noted in two treated eyes one hour after treatment and persisted in one eye at the 24-hour observation. No other iridial effects were noted. Minimal to moderate conjunctival irritation was noted in all treated eyes one hour after treatment. Minimal conjunctival irritation was noted in two treated eyes at the 24-hour observation and in one treated eye at the 48 and 72-hour observations.

Other effects:

None

Interpretation of results:

GHS criteria not met

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

In an eye irritation study conducted according to OECD Test Guideline 405 and in compliance with GLP (reliability score 1) dicyclopentyl(dimethoxy)silane was not 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

There are several equally reliable in vivo studies for each of the skin and eye irritation endpoints. In the case of skin irritation, the study that gave clear positive results was selected as the key study. There are two additional studies (Research & Consulting Company Ltd., 1995c and Huntingdon research Centre Ltd., 1995c) that showed irritation to be below the classifiable level for Regulation (EC) No 1272/2008. However, in one of these studies the irritation was only slightly below that required for classification.

In the case of eye irritation, all results were negative.

There are no specific studies of respiratory tract irritation. However, a 4-day inhalation exposure study in rats (Dow Corning Corporation, 1993) indicated that the substance may have potential to cause local irritation of the respiratory tract following repeated exposures.

Justification for classification or non-classification

Based on the available data dicyclopentyl(dimethoxy)silane is classified as 'Cat 2: irritant', with the hazard statement 'H315: Causes skin irritation' according to the criteria of Regulation (EC) No 1272/2008.

No specific studies are available on corrosivity of dicyclopentyl(dimethoxy)silane. However, based on the available skin irritation studies, conducted according to OECD Test Guideline 404, the substance does not have corrosive effects.

All the available data for eye irritation indicate that the substance is not irritating to rabbit eyes. However, the official classification of dicyclopentyl(dimethoxy)silane in Annex VI of Regulation (EC) No 1272/2008 is 'Cat 1: Eye damage', with the hazard statement 'H318: Causes serious eye damage'.