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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin 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:
guideline study with acceptable restrictions
Remarks:
The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline. No mention of GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Trimethoxysilane
EC Number:
219-637-2
EC Name:
Trimethoxysilane
Cas Number:
2487-90-3
Molecular formula:
C3H10O3Si
IUPAC Name:
Trimethoxysilane
Test material form:
liquid

Test animals

Species:
rabbit
Strain:
New Zealand White

Test system

Type of coverage:
occlusive
Preparation of test site:
not specified
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.5 ml
Duration of treatment / exposure:
Four hours
Observation period:
14 days
Number of animals:
Six

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24, 48 and 72 hrs
Score:
6.53
Remarks on result:
other: PII (24-, 48- and 72-hour scores for erythema/eschar and edema formation) = 6.53
Irritation parameter:
erythema score
Basis:
animal #1
Remarks:
87-29367
Time point:
24/48/72 h
Score:
2.66
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
positive indication of irritation
Irritation parameter:
erythema score
Basis:
animal #2
Remarks:
87-29373
Time point:
24/48/72 h
Score:
1.33
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
positive indication of irritation
Remarks:
The dose site of this rabbit could not be scored until 2 days because the gauze patch (used in dose application) had completely adhered to the skin.
Irritation parameter:
erythema score
Basis:
animal #3
Remarks:
87-28182
Time point:
24/48/72 h
Score:
3
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
positive indication of irritation
Irritation parameter:
erythema score
Basis:
animal #4
Remarks:
87-29397
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
positive indication of irritation
Irritation parameter:
erythema score
Basis:
animal #5
Remarks:
87-29400
Time point:
24/48/72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
probability of weak irritation
Irritation parameter:
erythema score
Basis:
animal #6
Remarks:
87-29402
Time point:
24/48/72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
probability of weak irritation
Irritation parameter:
edema score
Basis:
animal #1
Remarks:
87-29367
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
fully reversible within: 10 days
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Basis:
animal #2
Remarks:
87-29373
Time point:
24/48/72 h
Score:
2.66
Max. score:
4
Reversibility:
fully reversible within: 14 days
Remarks on result:
positive indication of irritation
Remarks:
The dose site of this rabbit could not be scored until 2 days because the gauze patch (used in dose application) had completely adhered to the skin.
Irritation parameter:
edema score
Basis:
animal #3
Remarks:
87-28182
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
fully reversible within: 10 days
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Basis:
animal #4
Remarks:
87-29397
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
fully reversible within: 14 days
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Basis:
animal #5
Remarks:
87-29400
Time point:
24/48/72 h
Score:
3.33
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Basis:
animal #6
Remarks:
87-29402
Time point:
24/48/72 h
Score:
4
Max. score:
4
Reversibility:
fully reversible within: 10 days
Remarks on result:
positive indication of irritation
Irritant / corrosive response data:
A 4-hour application of 0.5 ml of trimethoxysilane to occluded rabbit skin resulted in moderate to severe erythema, severe edema and necrosis on 6 of 6 rabbits.  Ecchymoses were present on the dose site of 3 animals.  
The dose site of one rabbit could not be scored until 2 days because the gauze patch (used in dose application) had completely adhered to the skin.  Four rabbits exhibited fissuring within 3 days.  Erythema was no longer present on any of 6 animals at 7 days and edema was no longer observed after 14 days.  However, desquamation, ulceration, scabs and alopecia developed on all rabbits within 7 to 14 days.  Thus, severe irritation was present through 14 days.  Two animals were found dead at 12 days.  There was no indication that these deaths were related to the dose, although they could have resulted from a secondary infection.
Other effects:
Two animals were found dead at 12 days. There was no indication that these deaths were related to the dose, although they could have resulted from a secondary infection.

Any other information on results incl. tables

   

 Mean Erythema Score

Mean Edema Score

5 hrs

 3.0

3.2
 1 day  3.0  3.6
 2 days  2.7  4.0
 3 days  2.3  4.0
 7 days  0  0.8
 10 days  0  0.3
 14 day  0  0


A 4-hour application of 0.5 ml of trimethoxysilane to occluded rabbit skin resulted in moderate to severe erythema, severe edema and necrosis on 6 of 6 rabbits. Ecchymoses were present on the dose site of 3 animals. The dose site of one rabbit could not be scored until 2 days because the gauze patch (used in dose application) had completely adhered to the skin. Four rabbits exhibited fissuring within 3 days. Erythema was no longer present on any of 6 animals at 7 days and edema was no longer observed after 14 days. However, desquamation, ulceration, scabs and alopecia developed on all rabbits within 7 to 14 days. Thus, severe irritation was present through 14 days.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (corrosive) based on GHS criteria
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
In a skin irritaton study (reliability score 2), conducted using a protocol similar to OECD Test Guideline 404 but with no mention of GLP, trimethoxysilane was corrosive to the skin of rabbits after a four hour exposure.