The European Chemicals Agency (ECHA) has announced the addition of six substances of very high concern (SVHCs) to its Candidate List in January 2025. This update, finalised during the December 2024 Member State Committee (MSC) meeting, includes Octamethyltrisiloxane, a widely used silicone compound now flagged for its environmental persistence and bioaccumulation concerns.
Six New Substances of Very High Concern
ECHA and the MSC confirmed the following six SVHCs for inclusion in the Candidate List:
- Octamethyltrisiloxane (CAS 107-51-7, EC 203-497-4): A versatile silicone compound flagged for its very persistent and very bioaccumulative (vPvB) properties.
- O,O,O-triphenyl phosphorothioate (CAS 597-82-0, EC 209-909-9): Recognised for its hazardous impacts under REACH.
- Reaction mass of triphenylthiophosphate and tertiary butylated phenyl derivatives (CAS 192268-65-8, EC 421-820-9): An organophosphate known for environmental risks.
- Perfluamine (CAS 338-83-0, EC 206-420-2): A perfluorinated compound associated with significant environmental concerns.
- Tris(4-nonylphenyl, branched and linear) phosphite: Included for its potential to disrupt endocrine systems.
- 6-[(C10-C13)-alkyl-(branched, unsaturated)-2,5-dioxopyrrolidin-1-yl] hexanoic acid (CAS 2156592-54-8, EC 701-118-1): Added without the MSC's direct involvement due to clear hazard classifications.
Octamethyltrisiloxane: A Closer Look at Its Uses and Concerns
Octamethyltrisiloxane, also known as D3 siloxane, is a volatile silicone compound with diverse applications:
- Personal Care Products: Commonly used in cosmetics and skin care formulations, it acts as a carrier and enhances product spreadability.
- Industrial Applications: Plays a role in manufacturing silicone polymers, lubricants, and greases.
- Coatings and Sealants: Contributes to water repellency in construction and automotive coatings.
- Textile and Leather Treatment: Imparts softness and water resistance to treated materials.
Despite its functional benefits, Octamethyltrisiloxane is now classified as an SVHC due to its environmental persistence and potential for bioaccumulation, raising concerns about long-term ecological impacts.
