Registration Dossier

Administrative data

Description of key information

No data are available for the registered substance for skin or eye irritation. Data from structurally analogous substances octamethyltrisiloxane (L3, CAS 107-51-7) and 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7) have therefore been included as weight of evidence of the lack of irritant effects. A study of skin irritation for octamethyltrisiloxane (L3, CAS 107-51-7), found the test material not irritating to rabbit skin in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP (RCC 1999). A study with 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7), carried out to OECD 404 and in compliance with GLP, found the test substance not irritating to the skin of rabbits (Wacker 2002). These are used as weight of evidence to demonstrate the absence of skin irritation properties. For eye irritation, a study conducted according to OECD TG 405 and compliant with GLP for 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7) is included as weight of evidence, and reports no irritant effects (LPT 2002).

Key value for chemical safety assessment

Skin irritation / corrosion

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:
4 March 2002 to 30 July 2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
GLP compliance:
yes (incl. certificate)
Species:
rabbit
Strain:
Himalayan
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Laboratory of Pharmacology and Toxicology KG, branch Löhndorf, D-24601 Löhndorf/Post Wankendorf
- Age at study initiation: approximately nine months
- Weight at study initiation: 2.6 to 3.1 kg
- Housing: singly in cages measuring 425 mm x 600 mm x 380 mm.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 20 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20± 3 (deviations from maximum range may have occurred e.g. during cleaning)
- Humidity (%): 55± 15 (deviations from maximum range may have occurred e.g. during cleaning)
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12
Vehicle:
unchanged (no vehicle)
Controls:
other: for each animal, the left eye served as an untreated control
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml
Duration of treatment / exposure:
Until the end of the observation period as the eyes were not rinsed
Observation period (in vivo):
Eyes were examined ophthalmoscopically with a slit lamp prior to the administration and 1, 24, 48 and 72 hours after administration
Number of animals or in vitro replicates:
Three females
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing (if done): Not done

SCORING SYSTEM: According to OECD 405 (see "Any other information on materials and methods incl. tables")

TOOL USED TO ASSESS SCORE: hand-slit lamp and fluorescein (24 hours after administration)
Irritation parameter:
overall irritation score
Basis:
animal: 1, 2 and 3
Time point:
other: All
Score:
0
Reversibility:
other: n/a
Remarks on result:
other: No signs of eye irritation were seen in any animal at any time point
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
cornea opacity score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
2
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
2
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
2
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
3
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
3
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
3
Remarks on result:
no indication of irritation
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
No effects
Other effects:
No other effects observed
Interpretation of results:
GHS criteria not met
Conclusions:
In a GLP study, conducted to OECD Test Guideline 405, no signs of irritation were seen in the eyes of female rabbits treated with 0.1 ml of undiluted Siloxan HSi2.
Executive summary:

In a GLP-compliant study carried out according to OECD Test Guideline 405, Siloxan HSi2 was tested for its potential to irritate the eyes of rabbits.

 

Three female Himalayan rabbits were each given a 0.1 ml instillation of undiluted Siloxan HSi2 into the right eye, with the left eye acting as an untreated control. Treated eyes were not washed, and were examined at 1, 24, 48 and 72 hours after treatment. After 24 hours, the eyes were examined with the aid of fluorescein.

 

There were no signs of irritation to the cornea, iris or conjuctivae over the course of the study in any of the treated rabbits. Under the conditions of this study, 0.1 ml of Siloxan HSi2 was not irritating to the eyes of rabbits.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Additional information

The available data for skin irritation for the structurally analogous substance octamethyltrisiloxane (L3, CAS 107-51-7) reports no signs of irritation in any of the test animals. No corrosive effects were noted on the treated skin of any animal at any measuring interval. Both the erythema and edema scores were 0 at 24, 48 and 72 hours (RCC 1999). Similarly, the skin irritation study for 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7) reports no irritant effects in any of the animals at any time points, with no other effects (Wacker, 2002). Both studies exposed rabbits to undiluted test substance, under semi-occlusive dressing for 4 hours.

The available data on eye irritation reports no signs of irritation in the eyes of rabbits treated with undiluted 1,1,3,3-tetramethyldisiloxane (H2 -L2 CAS 3277-26-7) (LPT 2002). All scores at all time points for all animals were zero.


Justification for classification or non-classification

Based on the studies carried out with the structurally analogous substances octamethyltrisiloxane (L3, CAS 107-51-7) and 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7) in which no irritant effect were evident to the skin or eyes of rabbits, no classification is proposed for the registered substance 1,1,1,3,5,5,5,-heptamethyltrisiloxane for irritation in accordance with Regulation (EC) No 1272/2008.