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Administrative data

Description of key information

The key study for skin irritation 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 (Dow Corning Corporation, 1999). The key study for eye irritation is read across from the structurally analogous decamethyltetrasiloxane (CAS 141-62-8). Very slight transient irritation was evident in two out of the three test animals which did not meet the EU criteria for classification for irritation (Dow Corning 2000).

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:
1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.2500 (Acute Dermal Irritation)
GLP compliance:
yes
Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: not stated
- Age at study initiation: not states
- Weight at study initiation: 2253-2685g
- Housing: individually in suspended metal cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 11

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 15-17.5
- Humidity (%): 54-76
- Air changes (per hr): ca. 18
- Photoperiod (hrs dark / hrs light): 12/12

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
- Concentration (if solution): undiluted

Duration of treatment / exposure:
single application
Observation period:
72 hours
Number of animals:
3 females
Details on study design:
TEST SITE
- Area of exposure: dorso-lumbar skin
- Type of wrap if used: semi-occlusive dressing

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: 4 hours

SCORING SYSTEM: Draize
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema 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 dermal irritation was observed.
Other effects:
There was no evidence of systemic response to treatment. No dermal irritation was observed.
Interpretation of results:
GHS criteria not met
Conclusions:
The test material was found not irritating in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.
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:
22 October 1998 to 10 February 2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
The study was conducted according to an appropriate EPA OPPTS guideline 870.2400, and in compliance with GLP, and was considered to be reliability 1 (reliable without restrictions). Read across to the registered substance is considered scientifically justified; the read across is considered to be reliability 2.The study was conducted according to and in compliance with GLP.
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.2400 (Acute Eye Irritation)
Deviations:
no
GLP compliance:
yes
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: removed from report
- Age at study initiation: at least 11 weeks
- Weight at study initiation: 2081 to 2664 g
- Housing: housed individually in suspended metal cages with perforated floors measuring 45.5 cm high, 76 cm wide and 60.5 cm deep (floor area 4598 cm2). The cage size is in compliance with animal welfare guidelines. Absorbent cage liners were placed in the pan below the metal mesh floor of the animal cages to absorb liquids
- Diet (e.g. ad libitum): standard diet, ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 15 days (screen animal), 27 days (additional two animals)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 15-22.5
- Humidity (%): 43-78
- Air changes (per hr): ~18
- Photoperiod (hrs dark / hrs light): 12/12
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:
Three days (i.e. no washing)
Observation period (in vivo):
Three days
Number of animals or in vitro replicates:
Three females
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing (if done): No washing


SCORING SYSTEM: Draize JH Appraisal of the Safety of Chemicals in Foods, Drugs & Cosmetics, Assoc. Food & Drug Officials of the USA, Austin, TX; 1959 (see attached document for more details)


TOOL USED TO ASSESS SCORE: hand-slit lamp
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:
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:
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:
overall irritation score
Basis:
animal #1
Time point:
other: all (1 hour, 1, 2 and 3 days)
Score:
2
Max. score:
110
Reversibility:
fully reversible within: 24 hours
Remarks on result:
other: very slight conjunctival irritation
Irritation parameter:
overall irritation score
Basis:
animal #2
Time point:
other: all (1 hour, 1, 2 and 3 days)
Score:
0
Max. score:
110
Reversibility:
other: not applicable
Remarks on result:
other: no signs of irritation
Irritation parameter:
overall irritation score
Basis:
animal #3
Time point:
other: all (1 hour, 1, 2 and 3 days)
Score:
2
Max. score:
110
Reversibility:
fully reversible within: 24 hours
Remarks on result:
other: very slight conjunctival 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:
A single instillation of 0.1 ml Dow Corning 200 (R) Fluid 1.5 cSt, into the eye of the rabbit elicited transient hyperaemia of the blood vessels of the conjunctivae in two animals. Ocular reactions had resolved completely in both animals by one day after instillation. There were no signs of irritation in the third animal.
Other effects:
No deaths occurred during the study. No clinical signs of systemic reaction to treatment were observed.
Interpretation of results:
GHS criteria not met
Conclusions:
Under the conditions of this study, conducted according to EPA OPPTS guideline 870.2400 (Acute Eye Irritation) and to GLP, 0.1 ml Dow Corning 200(R) Fluid 1.5 cSt instilled into the eyes of rabbits elicited very slight transient conjunctival irritation in two of three animals. The test material was considered to be not irritating to eyes.
Executive summary:

In a GLP study conducted according to US EPA Health Effects Test Guideline OPPTS 870.2400 (Acute Eye Irritation), 0.1 ml Dow Corning 200® Fluid, 1.5 cSt was administered to the lower lid of one eye of one female rabbit. This was performed in advance of the similar dosing of a further two females to ensure that if a severe response was produced, no further animals would be exposed. All animals were observed over three days, and scored for eye irritation at 1 hour, and 1,2 and 3 days after instillation.

There was no evidence of systemic toxicity in any of the animals following treatment. Transient hyperaemia of conjunctival blood vessels was observed in two rabbits, and resolved completely within 24 hours. No other signs of eye irritation were observed in any treated animal.

Under the conditions of this study, Dow Corning 200® Fluid, 1.5 cSt was non-irritating to the eyes of rabbits according to EU criteria.

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

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

The key study for skin irritation was a reliable 4 hour, semi-occlusive study, conducted in compliance with GLP (Dow Corning 1999).

No dermal irritation was observed and there was no evidence of systemic response to treatment.

The available supporting data for skin irritation reports no irritant effects in any of the test animals in response to a 4 hour, semi-occlusive application. 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).

The key study for eye irritation is read across from the structurally analogous decamethyltetrasiloxane (CAS 141-62-8) (Dow Corning 2000). The study was conducted according to an appropriate EPA OPPTS guideline 870.2400, and in compliance with GLP, and was considered to be reliability 1 (reliable without restrictions). Read across to the registered substance is considered scientifically justified. The study was conducted according to and in compliance with GLP. A single instillation of the test substance, into the eye of the rabbit elicited transient hyperaemia of the blood vessels of the conjunctivae in two animals. Ocular reactions had resolved completely in both animals by one day after instillation. There were no signs of irritation in the third animal. The test material was considered to be not irritating to eyes.

READ-ACROSS JUSTIFICATION

Octamethyltrisiloxane (L3) belongs to the structural class of siloxanes (alkyl, vinyl, aryl or hydrogen substituted). The substances all have high log Kow (increasing with increasing chain length) and low water solubility. In vivo skin and eye irritation studies are available for a number of these substances. For the registration substance itself, only skin irritation studies are available (Dow Corning Corporation, 1999; RCC, 1999).

The available studies for the linear siloxanes from this analogue group, as well as key physicochemical properties, are summarised in the table below. The results of the irritation studies for this analogue group are in agreement: there is no evidence from any of the available studies that the substances in this group have any potential for skin or eye irritation. It is therefore valid to read-across the lack of irritation between the members of the group where there are data gaps.

Summary of key irritation data for linear siloxanes

Substance

L2

L3

L4

L5

Chemical name

Hexamethyl

disiloxane

Octamethyl

trisiloxane

Decamethyl

tetrasiloxane

Dodecamethyl

pentasiloxane

CAS number

107-46-0

107-51-7

141-62-8

141-63-9

Water solubility (mg/l)

0.93

0.034

6.7E-03

7.5E-05

Log Kow

5.1

6.6

8.1

9.4

Skin irritation result

Not irritant (Dow Corning Corporation, 1996)

Not irritant (Dow Corning Corporation, 1999)

Not irritant (Dow Corning Corporation, 2009d)

Not irritant (Dow Corning Corporation, 2009e)

Eye irritation result

Not irritant (Stauffer, 1973)

-

Not irritant (Dow Corning Corporation, 2000)

-



Justification for classification or non-classification

Based on the available information on the registered substance, L3 is not classified for skin or eye irritation according to Regulation (EC) No 1272/2008.