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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:
key study
Study period:
23 January 2009 to 3 March 2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report date:
2009

Materials and methods

Test guidelineopen allclose all
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

Test material

Constituent 1
Chemical structure
Reference substance name:
Decamethyltetrasiloxane
EC Number:
205-491-7
EC Name:
Decamethyltetrasiloxane
Cas Number:
141-62-8
Molecular formula:
C10H30O3Si4
IUPAC Name:
2,2,4,4,6,6,8,8-octamethyl-3,5,7-trioxa-2,4,6,8-tetrasilanonane

Test animals

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

Test system

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)

Results and discussion

In vivo

Resultsopen allclose all
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.

Applicant's summary and conclusion

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.