Guidance

Environmental Risk Assessments in medicines

Published 1 April 2026

1. Background

This guidance sets out the expectations for environmental risk assessments (ERAs) for medicinal products in the UK.

All marketing authorisations (MAs) require an evaluation of the potential environmental risks posed by the medicinal product, as specified in Schedule 8 of the Human Medicines Regulations (HMR). This includes an assessment of the product’s potential environmental impact and a description of the proposed arrangements for limiting that impact.

An ERA evaluates the risk to the environment arising from use of the product, taking into account the physicochemical and ecotoxicological properties, as well as the environmental fate, of the active substance. Where the possibility of environmental risk cannot be excluded, specific measures to limit environmental impact should be proposed. Appropriate precautionary and safety measures should be included in the Summary of Product Characteristics (SmPC) and patient information leaflet (PIL), where applicable.

2. General ERA guidance

The Medicines and Healthcare products Regulatory Agency (MHRA) seeks to align environmental risk assessment (ERA) requirements with those of international regulatory authorities, while ensuring their appropriate application within the United Kingdom.

Applicants submitting Marketing Authorisation Applications (MAAs) and marketing authorisation holders (MAHs) of existing marketing authorisations (MAs) are expected to provide an ERA that is consistent with the European Medicines Agency’s (EMA) Guideline on the environmental risk assessment of medicinal products for human use (EMEA/CHMP/SWP/4447/00 Rev. 1- Corr.*, published in 2024). For UK submissions, an evaluation of the predicted environmental concentration based on UK prevalence should be provided, where available. An assessment based on prevalence data from an EU Member State may be acceptable, provided it is sufficiently conservative when compared with UK prevalence.

3. Submission of ERAs

An ERA is required to be submitted as part of an MAA, irrespective of the legal basis. An ERA is also required for post-approval changes and line extensions where an increase in environmental exposure is anticipated.

3.1 Initial Marketing Authorisation Applications

The ERA, or a justification for its absence, must be provided in Module 1.6 of the eCTD. Full study reports and copies of any literature cited in the ERA should be submitted. A justification for the absence of ERA studies may be acceptable where there is no expected increase in environmental exposure to the active substance.

An ERA is not required for renewal of a marketing authorisation. However, where new data emerge post-authorisation that necessitate an update to the ERA (for example, data indicating an anticipated increase in environmental exposure), this information must be submitted as a variation (see below).

3.2 Submission of ERAs post-authorisation

Where new data emerge post-authorisation that require an update to the ERA, this must be submitted as a variation.

Updates to the ERA supported by the results of environmental studies  or other data (including toxicological tests, evidence from post marketing experience or publications) that need to be newly assessed should be submitted as a Type II variation.

Updates to the ERA which does not include new environmental studies (e.g. recalculation of the risk quotients without producing new studies) can be submitted as a Type IB variation.

Please see MHRA guidance Medicines: apply for a variation to your marketing authorisation - GOV.UK for information on requirements for submitting variation to the MHRA.

3.3 Submission via the International Recognition Procedure (IRP)

An IRP may be used to submit an ERA post-authorisation where the Reference Regulator (RR) has approved the same ERA proposed for the UK, and where the assessment is sufficiently conservative when compared with UK prevalence. Applicants should refer to MHRA published guidance on Post-authorisation IRP applications: variations and renewals for information on submitting variations via IRP.

Where the RR has approved an ERA that is not the same as the ERA proposed for the UK, or where the ERA does not meet UK prevalence requirements, the updated ERA cannot be submitted via the IRP route and should instead be submitted via the direct national route. However, applicants are encouraged to submit the ERA approved by the RR and relevant supporting documentation, including the RR assessment reports, and to summarise in the cover letter any scientific divergence between the ERAs. When assessing the UK ERA, the MHRA will take into account the RR’s assessment, while noting that the UK assessment will be conducted in accordance with UK ERA requirements.