Decamethyltetrasiloxane

Endpoint summary

Description of key information

The key study for skin irritation performed according to OECD Test Guideline 404 and in compliance with GLP, found L4 non-irritating to the skin of three rabbits (Dow Corning Corporation, 2009b).

 

The key study for eye irritation conducted according to EPA OPPTS guideline 870.2400 (Acute Eye Irritation) and to GLP, showed very slight transient conjunctival irritation in two of three animals. The test material was considered to be not irritating to eyes (Dow Corning Corporation, 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:

23 January 2009 to 3 March 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

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: no data available
- Age at study initiation: approximately 4 months
- Weight at study initiation: 2660 to 2789 g
- Housing: individually
- Diet (e.g. ad libitum): standard diet, provided as recommended by animal vendor
- Water (e.g. ad libitum): purified municipal water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5 to 20.6
- Humidity (%): 51 to 62
- Air changes (per hr): 13.1
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 23 January 2009 To: 30 January 2009

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution): 100%

Duration of treatment / exposure:

Pilot study: 3 min, 1 hour, 4 hours (1 animal, three sites)
Confirmatory study: 4 hours (2 animals, 1 site/animal)

Observation period:

Pilot study: for 3-minute and 1-hour treatments, observation at 0 hours after patch removal; for 4-hour treatment, observations at 60 ± 5 min, 24 ± 2 hours, 48 ± 2 hours and 72 ± 2 hours after patch removal
Confirmatory study: for 4-hour treatment, observations at 60 ± 5 min, 24 ± 2 hours, 48 ± 2 hours and 72 ± 2 hours after patch removal

Number of animals:

1 male (pilot study)
2 males (confirmatory study)

Details on study design:

TEST SITE
- Area of exposure: no data available
- % coverage: no data available
- Type of wrap if used: coverlet wrapped by a layer of gauze bandage followed by a layer of elastic wrap (Elastoplast (R)). Animals were fitted with Elizabethan collars for at least 24 hours to prevent removal of bandaging.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): test substance removed following exposure period with water-moistened gauze, and dry gauze
- Time after start of exposure: presumably 3 mins, 1 hour or 4 hours

SCORING SYSTEM: EEC Primary Irritation Index (PII); EPA Primary Irritation Index (PII)

Irritation parameter:

erythema score

Remarks:

EEC

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Remarks:

EEC

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: overall

Score:

0

Max. score:

8

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of dermal irritation (erythema or oedema) were seen at any observation time point in any animal.

Other effects:

No dermal lesions or additional dermal findings were noted during the experimental phase. No remarkable changes in body weight were observed (mean body weight change of 30.7 with standard deviation 7.77). No animals died during the course of the study.

Interpretation of results:

GHS criteria not met

Conclusions:

In a GLP study performed according to OECD Test Guideline 404, decamethyltetrasiloxane (L4) was non-irritating to the skin of three rabbits when applied undiluted semi-occluded for 4 hours.

Executive summary:

In an acute dermal irritation/corrosion study carried out to GLP and according to OECD Test Guideline 404, rabbits were exposed dermally to decamethyltetrasiloxane (L4).

In a pilot study, 0.5 ml of the undiluted test substance was applied under occlusion to the shaved, intact skin of one male rabbit for three minutes or one hour. The test site was scored immediately after patch removal. The confirmatory study involved the treatment of the same animal, and two additional males, with the undiluted test substance under occlusion for four hours. Animals were observed at approximately 1, 24, 48 and 72 hours after patch removal.

No signs of dermal irritation or any other toxic effect were seen over the course of the study.

Under these experimental conditions, undiluted decamethyltetrasiloxane (L4) was non-irritating to the skin of rabbits when applied for up to four hours.

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

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: Covance Research, Kalamazoo, MI
- 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:

conjunctivae score

Basis:

animal #1

Time point:

other: One hour

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 24 hours

Remarks on result:

other: redness (transient hyperaemia of blood vessels)

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

3

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

other: One hour

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 24 hours

Remarks on result:

other: redness (transient hyperaemia of blood vessels)

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

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:

no indication 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 reported no signs of dermal irritation (erythema or oedema) at any observation time point in any animal when L4 was applied undiluted semi-occluded for 4 hours (Dow Corning Corporation, 2009c). No clinical signs, dermal lesions or remarkable changes in body weight were reported.

The key study for eye irritation reported no evidence of systemic toxicity in any of the animals following treatment. 0.1 ml of the test substance instilled into the eyes of rabbits elicited transient hyperaemia of conjunctival blood vessels in two rabbits, and resolved completely within 24 hours. No other signs of eye irritation were observed in any treated animal (Dow Corning Corporation, 2000).

Justification for classification or non-classification

Based on the available information, L4 does not require classification d for skin or eye irritation according to Regulation (EC) No 1272/2008.