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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:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline. It was not compliant with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1973
Report date:
1973

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
the animals were exposed to test substance for 24 hours, observation was not continued for 14 days to determine reversibility
GLP compliance:
no
Remarks:
The study pre-dates GLP

Test material

Constituent 1
Reference substance name:
2,2,4,4,6,6-hexamethylcyclotisilazane
IUPAC Name:
2,2,4,4,6,6-hexamethylcyclotisilazane
Constituent 2
Chemical structure
Reference substance name:
2,2,4,4,6,6-hexamethylcyclotrisilazane
EC Number:
213-773-6
EC Name:
2,2,4,4,6,6-hexamethylcyclotrisilazane
Cas Number:
1009-93-4
Molecular formula:
C6H21N3Si3
IUPAC Name:
2,2,4,4,6,6-hexamethylcyclotrisilazane

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
Very few details given in study report
Weight of animals at study initiation: 2.3 to 3.0 kg

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
other: The test substance was applied unchanged or as a 1%, 3%, 10% or 30% solution in peanut oil
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution): 1%, 3%, 10% or 30% solution in peanut oil

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 ml
Duration of treatment / exposure:
24 hours
Observation period:
72 hours
Number of animals:
six rabbits per concentration
Details on study design:
TEST SITE
- Area of exposure: approximately 3 cm in diameter, therefore 4.5 cm²
- % coverage: no data
- Type of wrap if used: The test substance was applied on an aluminium disk kept in place with adhesive tape and a bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no information
- Time after start of exposure: 24 hours

SCORING SYSTEM: Draize

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
mean
Remarks:
the erythema score for every animal was 4
Time point:
other: 24 hours
Score:
4
Max. score:
4
Reversibility:
no data
Remarks on result:
positive indication of irritation
Irritation parameter:
erythema score
Remarks:
Undiluted test material applied to intact skin
Basis:
mean
Remarks:
the erythema score for every animal was 4
Time point:
other: 72 hours
Score:
4
Max. score:
4
Reversibility:
no data
Remarks on result:
positive indication of irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
animal #1
Time point:
other: 24 hours
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 72 hours
Remarks on result:
probability of weak irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
animal #2
Time point:
other: 24 hours
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 72 hours
Remarks on result:
probability of weak irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
animal #3
Time point:
other: 24 hours
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
animal #4
Time point:
other: 24 hours
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 72 hours
Remarks on result:
probability of weak irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
animal #5
Time point:
other: 24 hours
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
animal #6
Time point:
other: 24 hours
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema score
Remarks:
Undiluted test substance applied to intact skin
Basis:
mean
Time point:
other: 72 hours
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
The data for lower concentrations showed a similar pattern to that seen with undiluted test substance, reducing in severity with reducing concentration:
30%: erythema 4 in all animals at 24 and 72 hours; edema 0 at 24 and 72 hours;
10%: erythema 4 in five out of six animals at 24, decreasing to 4 at 72 hours, no erythema in one rabbit; edema 0 at 24 and 72 hours;
3%: no erythema or edema observed in any animal.

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant) based on GHS criteria
Conclusions:
2,2,4,4,6,6-hexamethylcyclotrisilazane has been tested in a study similar to an OECD 404, prior to OECD GLP criteria being adopted. Application of undiluted substance to the intact skin of six New Zealand white rabbits for 24 hours resulted an erythema score of 4/4 in all animals at 24 and 72 hours. No further observations were made and there is no information on reversibilty of the observed erythema. Edema (score 1/4) was observed in three out of six animals at 24 hours, fully reversible within 72 hours. Test substance diluted in oil also resulted in erythema, but not edema. A 30% solution in peanut oil also resulted an erythema score of 4/4 in all animals at 24 and 72 hours. A 10% solution caused erythema in five out of six rabbits, with a score of 3/4 at 24 hours increasing to 4/4 at 72 hours. No erythema was observed at 24 hours after application of a 3% solution. It is concluded that the substance is irritating to the skin.