April 8, 2026 by Olivia Tran
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has finally provided guidance on environmental risk assessments (ERA) for medicines following its departure from the EU. Its approach is to align with ERA requirements of international regulatory authorities, notably the European Medicines Agency (EMA), and Marketing Authorisation Holders are expected to provide an ERA consistent with EMA’s ERA guidance published in 2024.
Specifically for the UK, predicted environmental concentrations (PECs) based on UK prevalence data should be provided, although prevalence for an EU Member State may be acceptable if it is sufficiently conservative when compared with UK prevalence. EMA’s ERA guidance allows refinement of the Phase I surface water PEC (PECSW) based on prevalence and treatment regime. One-year prevalence is preferred, with the data preferably not being older than 5 years and published by a reliable and independent source (e.g., a peer-reviewed journal).
For initial Marketing Authorisation Applications, a justification for the absence of ERA studies may be acceptable where there is no expected increase in environmental exposure. There is no further guidance on the situations where this approach would be acceptable, but this may be an approach that may be applicable for generic products.
An ERA is not required for marketing authorisation renewals unless new data emerges that require an update to the ERA or if there is an anticipated increase in environmental exposure (e.g. additional indication or product format). New environmental studies or other data (e.g., toxicological tests, real-world post-marketing evidence) should be submitted as a Type II variation, whereas ERA updates that do not include new studies (e.g. PEC recalculations) should be submitted as a Type IB variation. An ERA approved by a Reference Regulator can also be submitted post-authorisation to the UK but must be sufficiently conservative in terms of UK prevalence, and a summary should be provided detailing any points of scientific divergence between the ERA approaches.
wca have extensive experience in literature searching, identifying quality information for prevalence refinements and preparing robust scientific summaries and justifications based on the EMA ERA guidance. Please get in touch if you require support in preparing a pharmaceutical ERA for EU or UK submission.