What is EU REACH and why it matters for cosmetic silicones
The EU Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation — EC 1907/2006 — governs the use of chemical substances across all industrial and consumer product categories within the European Union. For cosmetic formulators, REACH intersects with the EU Cosmetics Regulation (EC 1223/2009) to create a dual compliance framework: products must comply with both the cosmetics safety rules and REACH restrictions on individual chemical substances.
The Substances of Very High Concern (SVHC) list, maintained by ECHA, is the mechanism through which REACH identifies chemicals requiring special attention. When a substance reaches the SVHC threshold in a finished product — 0.1% by weight — suppliers are obliged to provide information to downstream users, and in wash-off cosmetics, specific restrictions apply. Cosmetic silicones became a focal point of SVHC regulation starting in 2018, when cyclic siloxanes D4 and D5 were formally listed.
Cyclic siloxanes on the SVHC register
D4 (octamethylcyclotetrasiloxane, CAS 556-67-2) and D5 (decamethylcyclopentasiloxane, CAS 541-02-6) were added to the SVHC candidate list based on evidence of persistence, bioaccumulation, and toxicity (PBT properties) in aquatic environments. D6 (dodecamethylcyclohexasiloxane, CAS 540-97-6) followed in 2019.
The practical restriction for formulators: from January 2020, wash-off cosmetics placed on the EU market may not contain D4 or D5 at concentrations equal to or above 0.1% by weight. This applies to products rinsed from the body during use — body wash, shampoo, conditioner, shower gel, cleansing preparations, and shaving products. Leave-on cosmetics (serums, moisturisers, foundations, deodorants) are not subject to the wash-off restriction, though SVHC communication obligations still apply above the 0.1% threshold.
What is relevant in 2026
As of 2026, the core restriction framework remains the wash-off limit for D4 and D5. ECHA's ongoing review processes continue to evaluate whether restrictions should extend to leave-on products, or whether the 0.1% threshold should be tightened. Formulators working on multi-market products — particularly those selling into both EU and UK markets (which adopted REACH into UK law post-Brexit as UK REACH) — should monitor ECHA's Restriction Roadmap and the UK HSE's parallel schedule.
D6 does not carry the same wash-off restriction as D4/D5, though its SVHC listing means communication obligations apply. Formulators using D6-containing raw materials above 0.1% in any product must ensure their supply chain documentation reflects this, even for leave-on formats.
What this means for cosmetic formulators
Any formulation destined for EU or UK markets containing cyclic siloxanes needs to be screened against the current restriction schedule. Raw materials that contain D4 or D5 — including many sensory blends, emollient systems, and volatile carrier blends — need to be checked at use levels. INCI declarations on a TDS list active ingredients; the supplier's SVHC declaration confirms whether restricted substances are present above or below the 0.1% threshold.
For new product development, the practical implication is straightforward: specify D5-free raw materials for wash-off formulations, and use SVHC-compliant alternatives for any product where D5-equivalent performance is required. This is not merely a regulatory box-ticking exercise; buyers at international beauty brands now routinely include REACH/SVHC compliance requirements in their raw material specifications.
Available alternatives to restricted silicones
The cosmetic industry's response to D4/D5 restrictions has accelerated development of non-cyclic alternatives that replicate the volatile, light-textured carrier performance of cyclic silicones. Propyl trisiloxane (INCI: Propyl Trisiloxane) is the most established alternative for applications where D5 is typically used as a volatile carrier in skincare, suncare, and color cosmetics.
Nishka Alliance's NISH PT103 (Propyl Trisiloxane) is a linear, non-cyclic silicone with a volatility and solubility profile comparable to D5. It does not carry SVHC classification and has no wash-off concentration restriction under current EU REACH. For formulators transitioning a D5-based formula, NISH PT103 offers like-for-like substitution in many applications, with minor adjustment to loading levels to compensate for slight differences in evaporation rate.
How Nishka Alliance supports REACH compliance
Nishka Alliance maintains REACH compliance documentation for all speciality silicones supplied to EU and UK customers. Available documentation includes: SVHC declarations (confirming presence or absence of candidate list substances above 0.1%), REACH registration confirmation for applicable substances, Safety Data Sheets (SDS) prepared in GHS 16-section format in English and the key EU languages, and EC 1223/2009 Cosmetics Regulation conformity statements.
All documentation is available on request. Certificate of Analysis (CoA) is issued with every batch, and regulatory document packages can be assembled to support your product safety assessment or CPSR requirements.
Actionable steps for formulators
Review your current raw material portfolio against the SVHC candidate list — the ECHA website publishes the complete list, updated regularly. For any silicone raw material containing D4 or D5, obtain the supplier's current SVHC declaration and confirm use levels in your finished formulation. For wash-off formulations above 0.1% D4 or D5, reformulate with non-cyclic alternatives before EU or UK market launch. For leave-on formulations, ensure communication obligations are met in your supply chain documentation even if no restriction currently applies. Request updated SDS and compliance documents annually — regulatory status can change.
