UK REACH – RMOA for the cyclic siloxanes D4, D5 and D6 – call for evidence

Closed 1 May 2023

Opened 2 Mar 2023


The UK REACH work programme for 2022/23 states that the Agency for UK REACH will carry out an assessment to decide if it should recommend that the cyclic siloxanes octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) are added to Annex 14 (the Authorisation List) of UK REACH. This assessment will take the form of a Regulatory Management Options Analysis (RMOA). RMOA is a process through which the Agency assess the potential risks posed by a substance (or group of substances), identifies areas where further information is needed to fill information gaps and recommends regulatory measures to address any identified risks. This call for evidence aims to gather information and evidence that will support the preparation of this RMOA.

We are keen to obtain GB specific information about manufacture, import (including importation of mixtures and articles possibly containing the substance) and use of these substances and articles possibly containing these substances, and about possible alternatives.

UK REACH came into force at the end of the EU exit transition period (31st December 2020) and regulates the access of chemicals to the GB market. Under the Northern Ireland Protocol, EU REACH continues to regulate the access of chemicals to the Northern Ireland market.

Please support your contribution with references and reliable data (facts and figures) where possible.

Background note

Whilst the UK was still a member of the EU, D4, D5 and D6 were agreed as substances of very high concern (SVHCs). D4 has been identified as exhibiting PBT/vPvB properties, with D5 and D6 exhibiting vPvB properties. The acronym PBT refers to “persistent, bioaccumulative and toxic” and vPvB is “very persistent and very bioaccumulative”.

PBT and vPvB substances persist for long periods of time in the environment and are characterised by a high potential to accumulate in biota and are of specific concern because their long-term effects are rarely predictable. Once they enter the environment, exposure to these substances is very difficult to reverse, even if emissions are stopped.

D4 and D5 are already subject to restriction for use in wash-off cosmetics (cosmetics intended to be washed off after use) that was in force before EU exit, and so which was transferred to UK REACH.

Under EU REACH, D6 is now proposed to be restricted in wash-of cosmetics and D4, D5 and D6 are proposed to be restricted in leave-on cosmetics, waxes, polishes and other cleaning products. Details of this restriction proposal can be found here. D4, D5 and D6, were also included in ECHA’s 10th recommendation for substances to be included in Annex XIV of EU REACH. The recommendation was submitted to the European Commission in April 2021. So far, the European Commission has not decided which substances to take forward.

We wish to gather up to date information on all uses and emissions of D4, D5 and D6 in GB to inform the RMOA.

If you are unsure if the substance you are providing information for falls within scope of this RMOA please submit your information anyway.

HSE’s Confidentiality and GDPR statements

HSE tries to make its call for evidence procedure as thorough and open as possible.

Information provided in response to this call for evidence may be subject to publication or disclosure in accordance with the access to information regimes (these are primarily the Freedom of Information Act 2000 (FOIA), the General Data Protection Regulations (GDPR) and the Environmental Information Regulations 2004 (EIR)). Statutory Codes of Practice under the FOIA and EIR also deal with confidentiality obligations, among other things.

If you would like us to treat any of the information you provide as confidential, please make this clear in your response. If we receive a request under FOIA or EIR for the information you have provided, we will take full account of your explanation, but we cannot give an assurance that confidentiality can be maintained in all circumstances.

An automatic confidentiality disclaimer generated by your IT system will be disregarded for these purposes. Requests for confidentiality should be made explicit within the body of the response.

HSE will process all personal data in accordance with the GDPR. This means that personal data will not normally be disclosed to third parties and any such disclosures will only be made in accordance with the Regulations.

How to submit comments

Basic information can be provided in the call for evidence survey below. More detailed information should be provided in document(s) which can be submitted as attachments at the end of each section. We will not automatically publish information submitted in response to a call for evidence. However, it will be helpful if a “public version” of your information can be provided. We ask for this because we will share a draft version of the RMOA with interested stakeholders to allow them to comment on our proposed regulatory approach. By providing us with a non-confidential version of any information you submit, this will help us understand which information we can include in this draft RMOA. If you also want to provide confidential information in your submission, please additionally complete a “confidential version” and submit both versions as attachments. We will take account of both non-confidential and confidential information when deciding which regulatory approach to propose.

When responding to this questionnaire, please answer all question sets that are relevant to you. For example, if you manufacture the substance and also import the substance, please answer questions for both manufacture and import. You do not need to duplicate information if you have provided this under a previous question set. In this case, please indicate where in the questionnaire the information has been given. If you do not have time to complete this questionnaire (or do not find any questions relevant) but are willing to contribute information for the RMOA, please use the comment box under the question “Do you have any other information that you think might help HSE and/or the Environment Agency with this RMOA?” to indicate what information you are willing to share and tick that you are willing to be contacted by HSE and EA. This can be found in the section headed “Other information” at the end of this call for evidence.

By submitting information as part of this call for evidence, you agree that any data provided (excluding your personal details) can be shared with the Environment Agency.

The call for evidence lasts for 60 days and closes at 23:59 London time (BST).


  • RMOA


  • Registration, Evaluation, Authorisation & restriction of CHemicals (REACH)