2,2,4,4,6,6-hexamethylcyclotrisilazane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2016-01-27 to 2016-02-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Although the study was terminated, it was conducted according to an appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

Preliminary study

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Justification for non-LLNA method:

An LLNA study was not performed because the test method is not considered to be suitable for substances that contain silicon. Please refer to the attached document for further details.

Test material

Test material information

Test material form:

liquid

Details on test material:

- State of aggregation:
- Particle size distribution:
- Mass median aerodynamic diameter (MMAD):
- Geometric standard deviation (GSD):
- Shape of particles:
- Surface area of particles:
- Crystal structure:
- Coating:
- Surface properties:
- Density:
- Moisture content:
- Residual solvent:
- Activation:
- Stabilisation:
- Other:

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability under test conditions: undergoes hydrolysis in water
- Solubility and stability of the test substance in the solvent/vehicle: soluble in acetone

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Crl: HA

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River, Germany
- Housing: kept in groups in Terluran - cages on Altromin saw fibre bedding
- Diet: autoclaved hay and to Altromin 3122 maintenance diet for guinea pigs, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 55 +/- 10%
- Air changes (per hr): 10 x / hour
- Photoperiod (hrs dark / hrs light): 12/ 12

Study design: in vivo (non-LLNA)

No. of animals per dose:

25, 50, 75, 100 % : 2 animals
0.5, 1.0 %: 1 animal
2.5, 5.0 %: 1 animal

Details on study design:

RANGE FINDING TESTS: a solubility test was performed to define the maximum concentration which is technically applicable to the animals. The substance was soluble in the vehicle, acetone, at a concentration of 75%.
Different concentrations of the test item were applied topically to the flanks of the animals for 6 hours using occlusive dressing to determine the concentration for the main study.
2 animals were treated topically with concentrations of 100% and 50% of the test item (dissolved in dried acetone) on the left flank and of 75% and 25% of the test item (dissolved in dried acetone) on the right flank for 6 hours.
1 animal was treated topically with a concentration of 1% of the test item (dissolved in dried acetone) on the left flank and with a concentration of 0.5% of the test item (dissolved in dried acetone) on the right flank for 6 hours.
1 animal was treated topically with a concentration of 5% of the test item (dissolved in dried acetone) on the left flank and with a concentration of 2.5% of the test item (dissolved in dried acetone) on the right flank for 6 hours.

Positive control substance(s):

no

Results and discussion

Any other information on results incl. tables

Signs of systemic toxicity (tremor) and severe signs of irritation at the application sites (necrosis) were observed when 25, 50, 75 and 100% of test item were applied.

Erythema grade 2, which was unchanged 72 hours after patch removal was observed when 2.5 and 5.0% of the test item were applied. Erythema grade 1, which was fully reversible within 72 hours after patch removal was observed when 0.5 and 1.0% of test item were applied.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Systemic signs of toxicity and severe irritation (necrosis) were observed in animals treated with high doses of test substance, while grade 1 or 2 erythema was observed in animals treated with lower doses. The study was terminated due to adverse effects observed during the preliminary study.