The EU is once again tightening regulations on the silicone industry. According to the revised REACH regulation (EU) 2024/1328, effective May 2024, Octamethylcyclotetrasiloxane (D4) and Decamethylcyclopentasiloxane (D5) are completely banned in leave-on cosmetics, and industrial applications containing ≥0.1% (w/w) will face strict restrictions. More importantly, this regulatory trend is spreading across electronics, textiles, automotive, and other export sectors—yet many companies have not realized that the “ordinary silicone” they use may quietly carry excessive D4/D5.
The core issue lies in some low-cost silicones on the market, which are insufficiently depolymerized crude products with high levels of cyclic oligomers. Even if the final product is labeled as linear polydimethylsiloxane (PDMS), incomplete removal during production can leave significant D4 and D5 residues. The EU ECHA has already classified D4 as a PBT (persistent, bioaccumulative, toxic) substance and D5 as a vPvB (very persistent, very bioaccumulative) substance, with high sensitivity to environmental release.
“Many clients assume ‘as long as D4 isn’t directly added, it’s fine,’ but regulations focus on the final product content,” notes a technical director at a compliance testing agency. Recent cases include a batch of silicone for smartphone waterproof coatings detained by Dutch customs due to 0.12% D4 content, and a European skincare export facing claims and cooperation termination due to silicone impurities.
Expert recommendations to mitigate risk:
Distinguish linear vs. cyclic structures: Compliant silicone should be high-molecular-weight linear polymers; D4/D5 are by-products, not active components.
Request GC-MS test reports from suppliers: Confirm total D4+D5 < 1000 ppm (0.1%).
Prefer low-cyclic or cyclic-free certified silicones: Leading manufacturers now offer highly purified linear silicone with D4/D5 < 50 ppm.
Fortunately, domestic high-purity silicones can already meet compliance. Many suppliers confirm that their electronic- and cosmetic-grade silicones pass third-party SVHC screening and support REACH SVHC declarations and SCIP notifications.
In today’s era of global green trade barriers, invisible impurities can translate into visible losses. For exporters, the cost of one raw material check is far lower than the cost of a shipment return or product recall.
