As the EU’s REACH regulation continues to tighten, Chinese exporters of silicone oils and downstream products are facing new compliance challenges. Although silicone oils themselves are typically high-molecular-weight polymers, certain low-molecular-weight cyclic siloxane impurities—such as D4 and D5—have already been added to the SVHC (Substances of Very High Concern) Candidate List. Failure to proactively screen and control these substances may trigger legal obligations including notification, customs detention, or even rejection by EU customers.
As of the end of 2025, the European Chemicals Agency (ECHA) has officially included:
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Octamethylcyclotetrasiloxane (D4, CAS 556-67-2)
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Decamethylcyclopentasiloxane (D5, CAS 541-02-6)
in the SVHC Candidate List, citing “persistent, bioaccumulative, and toxic (PBT)” properties for D4 and “long-term toxicity to aquatic environments” for D5.
While polymeric silicone oils (e.g., PDMS) are generally exempt from REACH registration, if a product contains D4 or D5 above 0.1% (w/w) and the annual export volume exceeds 1 metric ton, the manufacturer or importer must:
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Submit a notification to ECHA, and
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Communicate safe use information down the supply chain.
“Many companies mistakenly believe that ‘silicone oil is inert, so no testing is needed’—this is a serious misconception,” warns the head of a third-party compliance consultancy. “In practice, incompletely cracked or inadequately purified silicone oils often contain hundreds to thousands of ppm of D4/D5. The risk is especially high in concentrated formulations like defoamers or mold release agents.”
Recent cases illustrate the real-world consequences:
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A batch of silicone oil intended for cosmetics was rejected and returned by a German buyer after D5 levels reached 0.15%, and the supplier failed to provide an SVHC declaration.
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An industrial lubricant supplier had its products delisted from Amazon due to outdated Safety Data Sheets (SDS) that omitted updated SVHC information.
To mitigate risks, experts recommend a three-step compliance strategy for exporters:
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Raw Material Screening: Require silicone oil suppliers to provide GC-MS test reports confirming SVHC levels (especially D4/D5).
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Finished Product Verification: Conduct full SVHC screening on formulated products (e.g., thermal greases, release agents).
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Regulatory Communication: If SVHC content exceeds 0.1%, prepare Section 3.2 of the SDS and submit a SCIP database notification.
Fortunately, many domestic Chinese laboratories now offer trace-level detection of D4/D5 (with detection limits as low as 10 ppm) and can issue CNAS-accredited REACH SVHC compliance reports.
In an era of rising green trade barriers, “compliance is not a cost—it’s a passport.” For China’s organosilicon industry—which accounts for over 70% of global production capacity—proactive regulatory alignment is essential to secure and expand access to the European market.
