This article covers only the current ASEAN regulatory status of D4. For the practical EU switchover timeline for D5/D6, see our D5 phase-out playbook. In early 2026 the Vietnam Drug Administration recalled 291 cosmetic products nationwide, with media coverage widely reporting the cause as “D4 and D5.” That reading is wrong. Both substances named in the recall — cyclotetrasiloxane and octamethylcyclotetrasiloxane — are the same compound (D4, CAS 556-67-2). For procurement teams sourcing silicone materials into Southeast Asia, separating signal from noise on the D4/D5/D6 question now saves a costly reformulation.
What actually changed
On 12 December 2025 the ASEAN Cosmetic Committee published the latest revision of Annex II (prohibited substances). The only cyclic siloxane listed is D4 (octamethylcyclotetrasiloxane, CAS 556-67-2 / 293-51-6, ACD Ref 1388). D5 (decamethylcyclopentasiloxane) and D6 (dodecamethylcyclohexasiloxane) are not currently prohibited in ACD Annex II or Annex III.
On 27 February 2026, citing the conclusions of the 42nd ASEAN Cosmetic Committee meeting (Singapore, 20–21 November 2025), Vietnam’s Drug Administration issued Decision No. 126/QĐ-QLD, revoking the notification numbers of 291 cosmetic products containing D4. Affected brands included Merzy, Paula’s Choice and Lemonade. Recall reports were due by 26 March 2026; downstream disposal and provincial supervision reports by 1 April.
The EU side is moving faster and wider. Regulation (EU) 2024/1328, amending REACH Annex XVII entry 70, restricts D4, D5 and D6 across cosmetics and other consumer mixtures, with two key dates: 6 June 2026 for substances and mixtures in general, and 6 June 2027 for all remaining cosmetic categories (including leave-on products and wash-off products containing D6).
Timeline at a glance
| Date | Region | Action |
|---|---|---|
| 2020-01-31 | EU | D4 / D5 ≥ 0.1% banned in wash-off cosmetics. |
| 2025-11-20 / 21 | ASEAN | 42nd ACC meeting concludes on D4. |
| 2025-12-12 | ASEAN | ACD Annex II revision: D4 entry (Ref 1388) gains CAS 293-51-6. |
| 2026-02-27 | Vietnam | DAV Decision 126/QĐ-QLD recalls 291 products on D4 grounds. |
| 2026-06-06 | EU | D4 / D5 / D6 ≥ 0.1% banned as standalone substances or in non-cosmetic mixtures. |
| 2027-06-06 | EU | All remaining cosmetic products (incl. leave-on with D4/D5/D6, and wash-off with D6) ≥ 0.1% banned. |
Sources: ACD Annex II revision Dec 2025; Vietnam DAV Decision 126; Commission Regulation (EU) 2024/1328.
What this means for buyers in Southeast Asia
For a brand selling only inside ASEAN, the practical conclusion is sharper than the headlines suggest. D4 in any cosmetic finished product is a recall risk in Vietnam today, and a likely enforcement priority across other ASEAN member states as they adopt the 42nd ACC conclusions. Reformulation or substitution is urgent for D4.
D5 is a different question. With D5 still permitted under ACD, panic-replacing D5 in products that stay within ASEAN may waste budget. But for any brand also exporting into the EU, leave-on products must be D5-free by 6 June 2027, and the same deadline applies to D6 in wash-off products going into the EU. Treat D5 and D6 as a single planning line.
Damongwz low-cyclics alternatives
Our volatile silicone fluids and elastomer gels are formulated for low residual cyclics, suitable for both ASEAN and EU destinations.
| Grade | INCI Name | Role | Cyclics (D4 / D5 / D6) |
|---|---|---|---|
| W201 | Dimethicone (volatile grade) | Low-viscosity, D5-like volatility | D4 typically < 100 ppm |
| W202 | Methyl Trimethicone | Fast evaporation, low freezing point, D5 replacement | Cyclics-free alkyl-modified backbone |
| W203 | Caprylyl Methicone | Pigment dispersion, transparent formulas, D5 / D6 replacement | Cyclics-free C8 alkyl-modified backbone |
Our latest incoming-lot analysis for W-series elastomer gels shows D4 residue of 64.64, 74.12 and 55.07 ppm across three production batches — well below the EU 1000 ppm (0.1%) threshold, with a safety margin of roughly 15×.
A Vietnamese customer told us recently: “We don’t sell which is relating to D5.” Demand for low-cyclics silicone is now mainstream, not niche.
See the full portfolio: Volatile Silicone Fluids · Silicone Elastomer Gels · All categories.
FAQ
Is D5 banned in ASEAN cosmetics?
No. Only D4 (octamethylcyclotetrasiloxane, ACD Annex II Ref 1388) is currently prohibited in the ASEAN Cosmetic Directive. D5 (decamethylcyclopentasiloxane) and D6 (dodecamethylcyclohexasiloxane) are not listed in Annex II or Annex III as of the 30 June 2026 update.
What is the difference between cyclotetrasiloxane and octamethylcyclotetrasiloxane?
There is no difference. Cyclotetrasiloxane and octamethylcyclotetrasiloxane are two IUPAC-style names for the identical compound D4 (CAS 556-67-2, EC 209-136-7). The 12 December 2025 ACD Annex II revision also added CAS 293-51-6 to the same entry.
Do I need to reformulate if I only sell within ASEAN?
For D4, yes — D4 must be below 0.1% in finished cosmetic products across ACD-aligned markets, and the Vietnam Drug Administration has begun enforcing this through nationwide recall notices. For D5 and D6, ASEAN markets currently do not require reformulation, although several member states adopt ACC conclusions within 6–12 months of each meeting.
How do I verify cyclics content in incoming shipments?
Request a Certificate of Analysis (COA) with quantitative GC-MS or GC-FID results for D4, D5 and D6, expressed in ppm or % by weight, and confirm the test method, detection limit and laboratory accreditation on the document. Damongwz provides per-batch COA with cyclics content for W201, W202 and W203, and can share testing reports on request.