1,1,3,3-tetramethyl-1,3-divinyldisiloxane

Sensitisation data (human)

Administrative data

Endpoint:

sensitisation data (humans)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

02.12.1991 to 10.01.1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Type of sensitisation studied:

skin

Study type:

study with volunteers

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Human Patch test to determine whether the test material was capable of sensitising the skin of human s under controlled patch test conditions.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hexamethyldisiloxane

EC Number:

203-492-7

EC Name:

Hexamethyldisiloxane

Cas Number:

107-46-0

Molecular formula:

C6H18OSi2

IUPAC Name:

hexamethyldisiloxane

Method

Type of population:

other: humans

Ethical approval:

not specified

Subjects:

- Age at study initiation: 18 to 78 years
- Number of subjects: 100

Clinical history:

Not specified

Controls:

Challenge and positive controls were not included.

Route of administration:

dermal

Details on study design:

TYPE OF TEST(S) USED: patch test (epicutaneous test)

ADMINISTRATION
1st application: Induction undiluted semiocclusive (0.2ml)
2nd application: Challenge undiluted semiocclusive (0.2ml)

One hundred subjects were employed in this study. Semi-occlusive, 2 cm x 2 cm Webril pad patches were applied to the infrascapular area of the back, either to the right or left of the midline. The induction phase consisted of application of the test material every 48 hours for a total of nine applications (applications made on Friday were not evaluated until Monday, prior to the re-application of test material) with the occlusive patch being removed after 24 hours. The test sites were evaluated prior to each application. Following the ninth evaluation, the subjects were dismissed for a 14-day rest period. After the rest period, identical patches were applied to sites previously unexposed to test material. These patches were removed 24 hours after application and were evaluated 48 hours and 72 hours after application. Each person was considered a complete case and used for evaluation of the material if they had six or more applications and subsequent readings during the first phase and at least one reading during the final phase.
Following the second application of the test material, a significant number of subjects developed superficial epidermal erosion. It was decided to change the occlusive patch condition to semiocclusive, applying the material to the same site beginning with the third application.




EXAMINATIONS
These patches were removed 24 hours after application and were evaluated 48 hours and 72 hours after application. Each person was considered a complete case and used for evaluation of the material if they had six or more applications and subsequent readings during the first phase and at least one reading during the final phase.

Results and discussion

Results of examinations:

Under the conditions employed in this study, there was no evidence of skin sensitisation to the test material. Following 24-hour semiocclusive application of 0.2 ml undiluted test material did not result in any sensitisation reaction in any of the 100 human subjects tested.

Applicant's summary and conclusion

Conclusions:

In a well conducted human patch test hexamethyldisiloxane was not sensitising to the skin of human volunteers. The study is well documented, meets generally accepted scientific principles and is acceptable for assessment.