UK MHRA: Guidance on Environmental Risk Assessments in medicines

Sharan Murugan
12 hours ago
2 min read

The UK regulatory landscape for medicines is increasingly evolving to integrate environmental protection alongside public health safety, and recently, on 1 April 2026, the UK MHRA updated its guidance on "Environmental Risk Assessments in medicines". A key component of this approach is the requirement for Environmental Risk Assessments (ERA), ensuring that medicinal products do not pose unintended risks to ecosystems during their lifecycle.

Background

Environmental Risk Assessment (ERA) is a mandatory requirement for all Marketing Authorisation (MA) applications under Schedule 8 of the Human Medicines Regulations (HMR). It ensures that pharmaceutical products are systematically evaluated for their potential impact on the environment, alongside their safety and efficacy for human use.

Environmental Risk Assessment (ERA):

An ERA is a scientific process used to evaluate the likelihood of environmental harm resulting from the use, disposal, and release of medicinal products.

It considers:

Physicochemical properties of the active substance
Ecotoxicity (impact on aquatic and terrestrial organisms)
Environmental fate (persistence, degradation, and bioaccumulation)

This assessment helps regulators understand how medicines behave once they enter the environment, particularly through patient excretion or improper disposal.

Risk Mitigation

Where environmental risks are identified and cannot be excluded, applicants must implement risk mitigation measures, including:

Strategies to minimise environmental exposure
Safety and precautionary statements in:
- Summary of Product Characteristics (SmPC)
- Patient Information Leaflet (PIL)

These measures ensure informed use and responsible disposal of medicines.

General ERA Guidance

The Medicines and Healthcare products Regulatory Agency (MHRA) requires ERA submissions to be scientifically robust, internationally aligned, and relevant to UK-specific conditions.

Alignment with EMA

Applicants submitting:

Marketing Authorisation Applications (MAAs)
Variations or updates to existing products

must follow the European Medicines Agency (EMA) Guideline on Environmental Risk Assessment (2024 revision).

This ensures consistency with global regulatory expectations and harmonisation across regions.

UK-Specific Requirements

For UK submissions, the ERA must include:

Predicted Environmental Concentration (PEC) based on UK usage data

If UK-specific data is unavailable:

Data from EU Member States may be used
Provided it is scientifically justified and does not underestimate UK exposure

This ensures a conservative and protective approach to environmental safety.

Key Concepts

Environmental exposure refers to the various pathways through which medicinal products enter the environment, including patient excretion, manufacturing discharge, and improper disposal practices, all of which must be carefully evaluated during the assessment process.

Ecotoxicological assessment focuses on understanding the potential harmful effects of medicinal substances on living organisms, particularly aquatic species, soil organisms, and microbial systems, to determine whether environmental concentrations could pose risks.

Environmental fate describes how a medicinal substance behaves once released into the environment, including its degradation rate, persistence in different environmental compartments such as water and soil, and its potential to bioaccumulate over time.

MHRA Expectations

The MHRA expects:

ERA to be integrated into the product lifecycle, not treated as a one-time activity
Applicants to justify all assumptions and data used in the assessment
Clear identification of risks and implementation of mitigation strategies

Compliance ensures both regulatory approval and environmental responsibility.