Article based on report in the January/February edition of European Rubber Journal magazine
London- European manufacturers of silicone rubber materials and products are facing stiff challenges on a number of fronts that look set to persist throughout the year.
Potentially, the biggest issue is the European Chemical Agency’s (ECHA) decision, last June, to add chemical intermediates D4, D5 and D6 to the REACH candidate list as substances of very high concern (SVHCs).
D4 (octamethylcyclotetrasiloxane), D5 (decamethylcyclopentasiloxane) and D6 (dodecamethylcyclohexasiloxane) are used as chemical intermediates in the production of a wide range of silicone materials.
D4 was deemed to meet the REACH criteria for ‘persistent, bioaccumulative and toxic’ (PBT) substances, and D5 and D6 the criteria for very ‘persistent, very bioaccumulative (vPvB)’ substances.
In addition, D5 and D6 were deemed PBT when they contain more than 0.1% D4 – though no exposure consideration is taken into account for SVHC assessment.
While SVHC candidate listing does not ban or restrict the use of D4, D5 and D6 or of silicone polymers, it does trigger communication and risk-management obligations.
As such, the European regulatory move is seen as a threat to the continued use of silicone polymers in many important applications, including in the healthcare, technology and energy sectors.
The ECHA decision is “disproportionate and unjustified,” believes Dr Pierre Germain, CES secretary general at CES Silicones Europe – sector group of European chemical industry association Cefic.
“The silicones industry strongly believes these substances do not exhibit PBT properties in real-life environments,” said Germain, who is also reconcile technical manager at the sector group.
The decision, he insists, does not take full account of the whole body of scientific evidence, or recognise already applicable and on-going regulatory activities.
“ECHA relied primarily on laboratory models and did not fully consider… newer and more accurate real-world data that show that siloxanes do not pose a risk to the environment,” said Germain.