Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

No skin sensitisation data are available for the registered substance therefore good quality data are read-across from the structurally analogous substance hexamethyldisiloxane (L2, CAS 107-46-0).

Read-across justification

1,1,3,3-Tetramethyldisiloxane (H2-L2) is a member of an analogue group of linear and cyclic siloxanes containing no reactive functional groups. The substances all have high log Kow(increasing with increasing chain length) and low water solubility. In vivo skin sensitisation data are available for a number of these substances, none of which shows any evidence of sensitisation.

Summary of key sensitisation 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

Skin sensitising result

Not sensitising (Dow Corning Corporation, 1992)

Not sensitising (RCC, 1999)

-

-

In addition to the data shown in the table, there is also no evidence of any skin sensitising potential for the corresponding cyclic siloxanes.

In light of the available data and the absence of any structural features indicative of skin sensitising potential, it is therefore valid to read-across a result of “not sensitising” where there are data gaps.

The key study for skin sensitisation is a well conducted human patch test study, for which GLP would not be applicable. The read-across substance hexamethyldisiloxane was not sensitising to the skin of 100 human volunteers when applied neat.


Migrated from Short description of key information:
No relevant studies are available on the registered substance. A human patch test study on the related hexamethyldisiloxane (CAS 107-46-0), which may be used as a read-across study, reported no evidence of sensitising potential.

Respiratory sensitisation

Endpoint conclusion
Additional information:
Migrated from Short description of key information:
No relevant data identified.

Justification for classification or non-classification

Based on the available information on the registered substance and read-across data, no classification is proposed for sensitisation in accordance with the current regulation (EC 1272/2008).