In an article published on June 21, 2018, by regulatory news provider Chemical Watch, reporter Emma Davies informed that the European Chemicals Agency (ECHA) identified three cyclic siloxanes as substances of very high concern (SVHC). At the meeting on June 12-14, 2018, ECHA’s Member State Committee agreed that D4 (octamethylcyclotetrasiloxane, CAS  556-67-2), D5 (decamethylcyclopentasiloxane, CAS  541-02-6) and D6 (dodecamethylcyclohexasiloxane, CAS 540-97-6) are very persistent and very bioaccumulative (vPvB), whereas D4 is also persistent, bioaccumulative and toxic (PBT). D5 and D6 can also be regarded as PBT, if D4 impurities are equal to or higher than 0.1% by weight.

D4 and D5 are already subject to targeted restrictions, e.g., in wash-off personal care products (FPF reported). The inclusion of these substances on the authorization list (Annex XIV) of REACH would override such restrictions.

In response, the silicone industry expressed strong reservations about the classifications of D4, D5, and D6 as SVHCs. Karluss Thomas, senior director of the American Chemistry Council’s Silicones Environmental, Health and Safety Center (SEHSC), referred to a recent scientific study, funded by industry and published in the scientific peer-reviewed journal Science of the Total Environment, and concluded “that there is negligible risk from exposure to the environment.”

In addition, U.S. and European silicones producers have taken legal action against the European Commission.

Read more

Emma Davies (June 21, 2018). “Echa’s MSC agrees that D4, D5 and D6 are SVHCs.Chemical Watch

Emma Davies (May 24, 2018). “D4 poses negligible risk to environment, says industry.Chemical Watch


Nusz, J.B., et al. (2018) “Use of multiple lines of evidence to provide a realistic toxic substances control act ecological risk evaluation based on monitoring data: D4 case study.” Science of The Total Environment 636:1382-1395.