A consolidated opinion of the Committees for Risk Assessment and Socio-Economic Analysis supporting ECHA’s proposal to restrict the use of the substances Octamethylcyclotetrasiloxane (D4); Decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) has been published.
The scope of the proposed restriction covers the uses of D4, D5 and D6 as a substance or in mixtures used by consumers and professionals. Industrial uses and use in articles are out of scope.
The substances D4, D5 and D6 have PBT and/or vPvB properties. PBT/vPvB substances rise specific concerns based on their potential to accumulate in the environment and cause effects that are unpredictable in the long-term and are difficult to reverse even when releases cease. Therefore, the risk from these substances cannot be adequately addressed in a quantitative way.
D4, D5 and, to a lesser extent, D6, are high tonnage substances. They are used as monomers for the production of silicone polymers, but also used as substances on their own or in the formulation of various mixtures that are subsequently used by consumers and professionals. The total releases to the environment have been estimated to be approximately 18 000 tpa.
Despite the already existing restriction on D4, D5 in wash-off cosmetics, that applies from 31 January 2020, the wide dispersive use of D4, D5 and D6 in cosmetic products remains the main source of releases.
The details on the scope of restriction are:
- Personal care products and other consumer/professional products like dry cleaning, washing and cleaning products, and waxes and polishes that contains D4/D5/D6 in concentrations higher than 0.1% shall not be placed on market.
- Wash off and rinse off cosmetic products containing DG in concentrations higher than 0.1% shall also not be placed on the market.
Although significant emission reductions (ca. 90%) could be obtained through the Annex XV restriction proposal on the use of D4, D5 and D6, emissions will not totally cease as releases will remain from uses of silicone polymers where the concentration of D4, D5 and D6 is below the limit proposed in the restriction.