Ongoing procedures


REACH Restriction proposal
(D4, D5, D6)

EU regulators have adopted a consumer and professional use restriction proposal for the placing of D4, D5 and D6 on the consumer and professional markets.

In parallel an authorisation proposal by ECHA for D4, D5 and D6 is under evaluation by the European Commission. It is also important to mention that other regulatory authorities outside the EU conducted risk evaluations of some volatile siloxanes including D4, D5 and D6. As of today there are no use restrictions in place outside the EU. 

The restriction would only apply to products on the European market.

The industry, in its contribution to the public consultation, sought further clarity to the derogation for industrial uses and proposed to extend derogations to essential consumer and professional applications:
dental impression and reproduction materials
personalised prosthetic devices e.g., limbs and hands
materials used for prototyping, including 3D printing

Following the proposal made by ECHA, its Committees for Risk Assessment (RAC) and Socio-Economic Analysis (SEAC) agreed that the proposed restriction is the most appropriate Union-wide measure. The proposal is, indicatively, set to be discussed in the June 2023 REACH committee meetings. After a positive vote, the proposal will be submitted to the Council of the European Union and the European Parliament for scrutiny.


In response to stakeholder input, ECHA proposed derogations for certain uses or for increased allowable concentrations for some uses of silicones including dental impression materials and medical devices for scar and wound management and stoma care. Intermediate use for D4, D5, D6 is out of scope of the proposed restriction.


Authorisation requirement
(D4, D5, D6)

On 14 April 2021, the European Chemicals Agency recommended for the European Commission to add D4, D5 and D6 to the Authorisation list because they are hazardous, produced in high volumes and widely used. The European Commission is yet to decide if it will follow the recommendation.

The silicone industry position is that the D4, D5 and D6 authorisation is an unnecessary and unjustified regulatory step. European authorities have themselves acknowledged that the restriction route, and not authorisation, is the most appropriate measure to regulate the use and placing on the market of the substances.


(D4, D5, D6)

The European Commission is currently considering proposing that the European Union nominate cyclic siloxanes D4, D5, D6 for listing in Annex B of the Stockholm Convention on Persistent Organic Pollutants (POPs). For a chemical substance to be classified as a POP, it needs to meet the Long-Range Environmental Transport (LRET) criterion. In other words, evidence needs to be presented that a substance can travel long distances from where it was originally released, even across continents and oceans, and can accumulate in a pristine environment very far away from any release points (e. g. production sites and municipal wastewater treatment plants). At present, a consensus has not been reached within the scientific community regarding the potential for long-range transport and the deposition of these substances in remote locations.


Silicones Europe is of the firm opinion that there is currently not enough evidence to claim that D4, D5, D6 meet the LRET criterion.
To solve the remaining scientific uncertainties around the LRET, Silicones Europe and the Global Silicones Council, both representing the silicone industry on the European and global levels, are working with an independent scientific panel – with the support of several EU Member State and third country authorities – to conduct a comprehensive field study in the Antarctic to gather robust scientific evidence. See our news section for updates on the progress of the study.

Given that the Stockholm Convention ultimately aims to eliminate substances globally, the availability of silicone polymers is at stake. With Europe’s high dependency on these substances, this threatens EU strategic autonomy and jeopardises many critical applications for the EU Green Deal, like batteries in electric cars, green hydrogen, semiconductors, to name a few.

Existing regulation

1st Mar 2022

CLH classification (D4)

1st Mar 2022

In 2022, the CLP Regulation categorised D4 as very toxic to aquatic life with long lasting effects and as suspected of damaging fertility. The rules apply since 1 March 2022.

1st Feb 2020

Wash-off personal care products restriction (D4,D5)

1st Feb 2020

Following a proposal made by the United Kingdom, the European Chemicals Agency (ECHA)’s Committees for Risk Assessment (RAC) and Socio-Economic Analysis (SEAC) agreed to restrict the use of D4 and D5 in wash-off personal care products in a concentration equal to or greater than 0.1% by weight of either substance. The restriction entered into force on 1 February 2020.


SVHC (D4, D5, D6)


In 2018, ECHA’s Member State Committee (MSC) agreed that D4, D5 and D6 should be included on the Candidate List of SVHC as substances that are very persistent, very bioaccumulative (vPvB). It also concluded that D4 meets the criteria for persistent, bioaccumulative and toxic (PBT) substances, and that D5 and D6 meet the same criteria if they contain more than 0.1% of D4.


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