The European Chemicals Agency (ECHA) decided in June 2018 to include the substances
- D4 (Octamethylcyclotetrasiloxane)
- D5 (Decamethylcyclopentasiloxane) and
- D6 (Dodecamethylcyclohexasiloxane)
on the EU REACH Candidate List for Substances of Very High Concern (SVHC).
SVHC is a term used in European chemical regulation REACH to list substances that meet certain criteria. In case of D4, D5 and D6 ECHA has decided to include these substances due to existing or predicted environmental properties (PBT and/or vPvB properties).
This inclusion does not mean that these substances or products containing these substances cannot be used anymore, neither that they are restricted nor forbidden due to this inclusion into the SVHC Candidate List. Moreover, the SVHC listing does not change the hazard labelling of the products concerned.
However, a SVHC listing may trigger communication and information obligations for substances, mixtures or articles containing D4, D5 or D6 at or above a concentration of 0.1% (w/w):
Chemical suppliers will inform within their supply chain if chemical products contain 0.1 % or more of D4, D5 and/or D6 by updating and distributing the relevant product safety data sheets (SDSs).
Manufacturers of articles containing above 0.1 % (w/w) SVHC have to submit sufficient information for safe use of article, at least the name of the SVHC substance, to the recipient.
SVHC is a term used in European chemical regulation REACH to list substances that meet certain criteria. In case of D4, D5 and D6 ECHA has decided to include these substances due to existing or predicted environmental properties (PBT – persistent, bioaccumulative and toxic and/or vPvB properties – very persistent, very bioaccumulative). In this regard is has to be considered that the test methods which underlie these criteria have been developed for organic carbon compounds and cannot straightforward be transferred to organic silicon compounds – especially with regard to the testing of persistence.
Other countries outside of the EU, amongst others Canada and Australia, as well as USA so far, have not found reasons to impose any kind of product restrictions on D4, D5 and D6. Scientific evidence and real-life data out of the environment have proved that silicones behave differently in the environment from what is predicted under EU REACH PBT and/or vPvB criteria.
Given this fact, the EU has not sufficiently recognized the full body of scientific evidence such as available studies, evidence on degradation of these substances in the environment and the particular physico-chemical properties of these substances during its considerations to include D4, D5 and D6 on the SVHC Candidate List.
Due to manufacturing processes, silicone products contain in several cases unintended amounts of D4, D5 and D6, where these substances are not an integral component to the product.
Silicones can be applied safely under normal conditions of use. They represent an economical, sustainable and safe chemical product class.