UK REACH – RP HP RMOA – Call for evidence

Closed 8 Apr 2023

Opened 7 Feb 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 RP HP (reaction products of 1,3,4-thiadiazolidine-2,5-dithione, formaldehyde and 4-heptylphenol, branched and linear [with ≥0.1% w/w 4-heptylphenol, branched and linear]) are added to Annex 14 (the Authorisation List) of UK REACH. This assessment will take the form of a Regulatory Options Management Analysis (RMOA). This call for evidence aims to gather information and evidence that will support the preparation of this RMOA. For this RMOA, we are interested in all forms of RP HP. We are not limiting the call for evidence to forms that contain ≥0.1% w/w 4-heptylphenol, branched and linear (4-HPbl).

We are keen to obtain GB specific information about manufacture, import (including importation of mixtures and articles possibly containing RP HP) and use of these substances and articles possibly containing RP HP, also about technology that could reduce levels of 4-HPbl in RP HP or alternatives to RP HP.

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

Reaction products of 1,3,4-thiadiazolidine-2,5-dithione, formaldehyde and 4-heptylphenol, branched and linear (RP-HP) with ≥0.1% w/w 4-heptylphenol, branched and linear (4-HPbl) are UVCB substances. UVCB substances are defined as substances of Unknown or Variable composition, Complex reaction products or Biological materials.

RP HP with ≥0.1% 4-HPbl was included in the European Chemical Agency’s (ECHA’s) 9th recommendation and was added to the Authorisation List in EU REACH (entry 57) on 12 April 2022 with a sunset date of 1 May 2025. In this case, it is the presence of the impurity 4-HPbl which is driving the regulatory approach for RP HP. This impurity was identified as a substance of very high concern (SVHC) on 12th January 2017 owing to its endocrine disrupting properties in the environment.

Information published by ECHA suggests that RP HP is used as a corrosion inhibitor in lubricants and greases including products (gear oils) that are supplied to consumers. Depending on the concentration of RP HP in the lubricant product, the levels of 4-HPbl in the finished product can vary.

An initial assessment carried out by the Agency in 2021 identified a need for further work to clarify if the substance that is listed in the EU Authorisation List is the main source of emissions of 4-HPbl in GB or if there are other relevant sources. Other uncertainties include the amount of the registered tonnage of RP-HP that falls within the scope of the SVHC composition. It is not known how easy it will be to substitute this SVHC composition with a non-SVHC composition (for example, how easy it is for manufacturers to carry out additional purification) or if suitable alternative corrosion inhibitors are available.

All substances, mixtures or articles that contain RP HP and/or 4-HPbl either intentionally or where it is present as an unintentional residue or by-product are within scope of this call for evidence.

If you are unsure if the substance you are providing information for falls within scope of the substance definition given in the EU Candidate List, 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)