Approach to substance evaluation in UK REACH

Published: March 2022 (version 1.2)


  1. Purpose/Aim
  2. Background and legislation
  3. HSE's approach to prioritisation criteria
  4. Future stakeholder engagement
  5. Declarations

1. Purpose/Aim

This document aims to set out the approach of the Health and Safety Executive (HSE, as the Agency for UK REACH) when considering substance evaluation and preparing the draft and final UK rolling action plan (RAP).

2. Background and legislation

Following the UK's withdrawal from the EU, UK REACH (retained Regulation (EC) No 1907/2006) came into force at the end of the transition period on 31 December 2020. UK REACH regulates the access of chemicals to the Great Britain (GB) market (comprising of the territories of England, Scotland and Wales).

Under Article 44(1) of UK REACH, there is a requirement for HSE to cooperate with the Appropriate Authorities (the AAs, as defined in UK REACH as the (Defra) Secretary of State and the Scottish and Welsh Ministers) to develop criteria for prioritising substances with a view to further evaluation. Article 44(2) states that these criteria shall be used to compile the draft RAP, which will cover a period of three years specifying the substances to be evaluated each year. The final RAP will be published on the HSE website. When exercising this function, HSE will use advice from the Environment Agency on any relevant environmental issues in accordance with Article 2B of UK REACH.

2.1 Criteria

In relation to the criteria for the evaluation of substances, Article 44(1) states:

  • Prioritisation shall be on a risk-based approach. The criteria shall consider:
    1. hazard information, for instance structural similarity of the substance with known substances of concern or with substances which are persistent and liable to bio-accumulate, suggesting that the substance or one or more of its transformation products has properties of concern or is persistent and liable to bio-accumulate;
    2. exposure information;
    3. tonnage, including aggregated tonnage from the registrations submitted by several registrants
  • Article 44(2) further states that
    "Substances shall be included if there are grounds for considering (either on the basis of a dossier evaluation carried out by the Agency or on the basis of any other appropriate source, including information in the registration dossier) that a given substance constitutes a risk to human health or the environment."

HSE has set out these criteria in more detail under "HSE's Approach to prioritisation" below.

2.2 Timeline

Article 44(2) states HSE must submit its draft RAP to the AAs within 12 months of the end of the transition period and give them an opportunity to comment on it. Within the 2021-2022 UK REACH work programme HSE committed to publishing the final RAP by 31 March 2022.

HSE must submit a draft annual update to its RAP by 31 May in each subsequent year, giving the AAs the opportunity to comment. HSE will then take account of comments from the AAs, adopt the final RAP and publish it on its website.

2.3 Context

Article 44 requires that:

  • Prioritisation shall be risk-based covering intrinsic hazard, exposure and tonnage, suggesting risk, hazard and exposure are elements that need to be taken into consideration
  • Substances subject to evaluation are registered under UK REACH
  • Substances shall be included if there are grounds for consideration that they constitute a risk to human health or the environment – the basis for this can come from dossier evaluation, or on the basis of any other appropriate information source, including (but not limited to) registration dossiers.

The criteria specified in Article 44 have been retained unamended from EU REACH 1 .

The 2021-2022 work programme also states that the UK approach to substance evaluation should seek to complement, not replicate, evaluation work performed by other regulatory regimes. Therefore, although the UK may evaluate a substance that has been previously evaluated elsewhere (e.g. in the EU), such an evaluation would be justified by a different identified use or concern.  

HSE is also aware of the work that has been undertaken by ECHA in the field of substance evaluation; along with ECHA's strategic approach , and their mapping of the 'universe' of registered substances 3, which is used to identify where further information is needed and if substance evaluation could play a part in that.

HSE will also look to further steers from the UK Chemical Strategy 4 and other mapping exercises in the future to inform our work on substance evaluation.

As the Comply with UK REACH-IT database is not yet fully populated, some information for prioritisation will be inferred for GB from information in ECHA's publicly available database. It will be appropriate to do this when it appears the industrial profile for a substance in GB is not substantially different to the EU.

When the UK database is populated, HSE will primarily use this GB specific information for substance evaluation decisions and drafting of the RAP.

3. HSE's Approach to prioritisation criteria

HSE's HSE's approach is based on how ECHA have set out the prioritisation criteria in the guidance document 'Selection criteria to prioritise substances for Substance Evaluation (2011 CoRAP selection criteria)'5. This document explains how ECHA view and use the criteria specified in EU REACH. HSE has adapted the criteria set out in this guidance to better fit the GB context and incorporate HSE's experience of substance evaluation from EU REACH. The principles for prioritising substances for substance evaluation are:

  • The criteria must be based on those in Article 44(1) of UK REACH.
  • Hazard- or exposure-related criteria should not be used in isolation for the prioritisation of substance, but in combination with each other - recognising that some flexibility may be required for individual substances where these are part of a group evaluation.
  • The criteria do not predefine the combination to be used. This is beneficial for the UK system, whereby the hazard of a substance may be known but more information may be required on exposure prior to assessing options for risk management – therefore, although all criteria are considered, we may have more information to be able to prioritise on hazard over exposure.
  • A suspected property is considered to be more of an important criterion than a known property – as further information is needed to confirm the existence of the suspected property. Evaluation gives the opportunity to gather this information and consider if further action is needed.
  • The criteria are not an exhaustive list of all possible risks that chemicals can cause.

3.1 Hazard-related selection criteria

The hazard related criteria that will be used to prioritise substances for evaluation are:

  • Suspected Persistent Bioaccumulative Toxic (PBT), very Persistent very Bioaccumulative (vPvB)
  • Substances that are suspected to be persistent and toxic, and for which environmental monitoring data or screening laboratory data (such as organic-water partitioning coefficient) indicate the likelihood of widespread distribution in the environment
  • Known PBT/vPvB
  • Suspected Endocrine Disruptors (ED) (e.g. based on reproductive effects and/or structural similarities)
  • Known Endocrine Disruptors
  • Suspected Carcinogenic, Mutagenic and Reprotoxic (CMRs) substances (e.g. based on structural similarities)
  • Known CMR
  • Suspected sensitisers (e.g. based on structural similarities)
  • Known sensitisers (skin and especially respiratory sensitisers)

These hazard-based criteria closely match those used by ECHA. Some additions have been made (see text in bold) to reflect updates since ECHA published its prioritisation criteria.

3.2 Exposure related selection criteria

The exposure related criteria that would be used to prioritise substances for evaluation are:

  • Wide dispersive use:
    • Number of sites where the substances is used
    • Pattern and amount of releases/exposures
    • Number/type reported uses & exposure scenarios from registrants
    • Substance is incorporated into mixtures/article with public use (consumers)
    • Potential size of the exposed population
  • Number of sites where the substance is used (if emission due to industrial use)
  • Consumer use and exposure of sensitive subpopulations such as children
  • Aggregated tonnage
  • Monitoring evidence

These criteria closely match the exposure criteria used by ECHA. HSE notes that some exposure information may not be initially available in the UK REACH registration database. EU data may be used as a proxy until GB-specific registration data is available.

3.3 Risk related selection criteria

HSE will use the same risk related criteria as set out in the ECHA guidance document:

  • Risk assessment in the Chemical Safety Report shows risk characterisation ratio (RCR) is not well below 1 (for human and/or environmental exposure)*
  • Cumulative exposure from structurally related substances with critical hazardous properties (e.g. similar ED property like antiandrogenic or oestrogen-like effect)

* This means that there is an unacceptable risk based on an exposure assessment, which aims to estimate the dose or concentration of a substance to which humans and/or the environment may be exposed.

3.4 Overall approach

Taking the hazard, exposure and risk-related criteria all into account will enable HSE to take the initial step in identifying if a substance is likely to constitute a risk to human health or the environment.

Additionally, HSE will take other relevant considerations or concerns into account. For example: grouping of substances for evaluation, specific types of substances such as nanomaterials and relevant issues which could be identified through the Defra-led UK chemicals strategy.

4. Future stakeholder engagement

HSE welcomes involvement and information from stakeholders in identification of substances to evaluate, and any information that they may have on how to best group substances. We will look to publish opportunities for specific involvement on the HSE website.

5. Declarations

Within this document we have provided links to the following ECHA documents found on ECHA's website:

Selection criteria to prioritise substances for Substance Evaluation (2011 CoRAP selection criteria)

Any documents or information accessed via ECHA's website are subject to ECHA's Legal Notice.

For the avoidance of doubt, no part of this guidance has been endorsed by ECHA.


  1. EU Regulation (EC) No 1907/2006. Back to reference of footnote 1
  2. Back to reference of footnote 2
  3. Back to reference of footnote 3
  4. The UK Chemicals strategy is a commitment from Defra as part of the 25-year environment plan, at the time of writing this is currently under development. Back to reference of footnote 4
  5. Back to reference of footnote 5

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Updated 2022-03-30