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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
other: experimental result from a mixture of submitted substance and structural analogue: partly read-across from structurally analogous substance
Adequacy of study:
key study
Study period:
Dec 18, 2000 to Jan 10, 2002
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Study according to OECD protocol, no deviations. - Test substance identified only by brand name and lot number , composition not specified in report, but confirmed by study owner to be a mixture of 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-99-0) - Name of testing facility and Study Director blanked out

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Remarks:
( No sentinel animal, not required in 2001)
GLP compliance:
yes
Remarks:
US-EPA TSCA GLP 40 CRF part 792

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
- three young adult females, at least 12 weeks old
- weight 3025-3137g at initiation
- identification by eartag & cage card
- housed in individual suspended cages
- inspection upon aarival; acclimatisation for at least 7 days, observed twice daily
- Diet: Certifeid Rabbit LabDiet(r) 5322 at approx. 150 gr/animal/day. Tap water at lib. Food and water regularly analysed
- controlled temperature (69-71 degr. F), humidity (50-64%) light (12/12) and ventilation (10-15 changes / days)

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped, not abraded.
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.5 ml / site
Duration of treatment / exposure:
4 hours
Observation period:
72 hours
Number of animals:
3
Details on study design:
application to skin area approx 2.5 x 2.5, covered with 8-ply surgical gauze held in place with surgical porous tape. Overwrapped with gauze bandaging an secured with non-irritating tape; Animals were given restraint collars.
Duration of application 4 hours, after which bandages were removed and sites wiped clean with disposable paper towels moistened with deionized water.
Scoring system according to OECD 404, July 17, 1992):
Erythema and eschar formation
0 (no erythema)
1: very slight erytheme (barely perceptible)
2: well defined erythema (slight)
3: Moderate to severe erythema
4: Severe erythema (beet redness) to slight eschar formation (injuries in depth)
Edema formation:
0: (no edema)
1: very slight edema (barely perceptible)
2 slight edema (edges of area well defined by definite raising)
3:moderate edema (raised approx. 1 mm)
4 Severe edema (raised more than 1 mm and extending beyond area of exposure

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 1 hr
Score:
0
Max. score:
0
Reversibility:
other: not applicable
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24 hrs
Score:
0
Max. score:
0
Reversibility:
other: not applicable
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 48
Score:
0
Max. score:
0
Reversibility:
other: not applicable
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 72
Score:
0
Max. score:
0
Reversibility:
other: not applicable
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: overall
Score:
0
Max. score:
0
Reversibility:
other: not applicable
Irritant / corrosive response data:
No animals showed any signs of irritation at any point in time
Other effects:
slight weight loss (1%) in one animal, not uncommmon in animals of this weight range and strain; not considered to be substance-related
no mortality.

Any other information on results incl. tables

Individual Irritation scores


Erythema


Edema


Animal nr.

Sex

1 hr

24 hrs

48 hrs

72 hrs


1 hr

24 hrs

48 hrs

72 hrs


34044

female

0

0

0

0


0

0

0

0


34045

female

0

0

0

0


0

0

0

0


34046

female

0

0

0

0


0

0

0

0



Total

0

0

0

0


0

0

0

0


PPI calculated for all timepoints: ppi = (0+0+0)/9 + (0+0+0) /9 = 0 + 0 = 0

Individual body weights:

Animal nr.

Sex

Initiation (day 0)

Termination (day 3)

34044

female

3137

3289

34045

female

30253034

3067

34046

female

3034

3020

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The mixture of stucturally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-99-0) showed no signs of skin irritation. Based on structural analogy, the conclusion applies directly to the registered substance as well as from read-across from the analogue
Executive summary:

A mixture of the two structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370 -99 -0) was tested for skin irritancy according to OECD 404 test method under GLP . No signs of skin irritation were observed. Based on structural analogy, the conclusion applies directly to the registered substance as well as from read-across from the analogue. Thus, the substance 2,4,6,8 -tetramethylcyclotetrasiloxane (CAS 2370-99-0) need not to be classified and labeled as skin irritants.