Toxicological Risk Assessment

Following an Extractables/Leachables (E&L) Study

ISO 10993-17:2023

Toxicological Risk Assessment of Medical Device Constituents

If you have performed an extractables/leachables (E&L) study to complete the chemical characterisation process of your device, then a toxicological risk assessment (TRA) of the findings from the E&L study may be required following the process described in ISO 10993-17:2023.

This process is intended to yield information which is useful in the overall biological risk assessment of the final product:

  • Whether constituents extracted from the medical device are at a quantity that could be a potential source of harm to health
  • A toxicological risk estimate based on the tolerable intake, or tolerable contact level, and worst-case estimated exposure dose for each constituent.
  • A worst-case estimated exposure dose for each constituent and subsequent toxicological risk estimation.
  • Derivation of a tolerable intake or tolerable contact level that is considered to be without appreciable harm to health.

Chorley Consulting have extensive experience conducting TRAs based on E&L data from a wide range of analytical laboratories. We can use a variety of tools to ensure relevant estimates of patient exposure and identify appropriate reference values.


Our Toxicological Risk Assessment Tools

Sometimes we all look to the gods for help. Assessing the biological safety of medical devices is an increasingly information-hungry process. To help us to help you, we have developed tools to streamline the process. We have named them after ancient Greek gods in the hope that they will guide us with their wisdom and preserve us from harm.

Metis is our database of toxicological profiles. It is named after Metis, an ancient Greek goddess of wisdom. Soteria is our tool, developed in-house, to streamline some of the processes within ISO 10993/17 (2023). It is named after Soteria, an ancient Greek goddess of safety and preservation from harm.

chorley consulting soteria

The recent update to ISO 10993/17 (2023) describes a process for the Toxicological risk assessment of medical device constituents, derived from either compositional information or analytical chemistry data (e.g. extractable data or leachable data).

The standard describes methods for a number of tools which may help the toxicologist reduce the number of chemicals which need to be evaluated. Estimate CMR & ED classification and exposure to aid MDR compliance.

Although use of concepts such as Total Quantity (TQ), Toxicological Screening Limit (TSL), Estimated Exposure Dose (EEDmax) and assumed release kinetics may reduce the burden for the toxicologist, establishing and justifying applicability as well as calculating some of the values from a large data set can itself be a time-consuming process.

To improve efficiency, we have developed Soteria, a validated Excel-based system, which we can use to check if chemicals fall within the scope of TSL, calculate TQ and EEDmax , and identify any CMR or ED substances (as defined in EU MDR).

  • Supports the application of ISO 10993-17 (2023).
  • Designed to support Toxicological Risk Assessment of medical devices.
chorley consulting metis

A critical step in evaluating the biological safety of your medical device is identifying the toxicological hazards posed by the substances in, or leaching from, the device. Sourcing this information can be a time consuming step and appropriate critical appraisal of the data requires relevant expert toxicological knowledge.

To help us streamline this process, Chorley Consulting have developed Metis, an in-house database of toxicological profiles of materials commonly used in medical devices.

The database contains fully referenced and internally peer reviewed summaries of toxicological data from a wide range of publicly available sources. Metis presently contains over 300 entries and is growing every day.

  • A curated database of toxicological profiles, specifically tailored for medical devices.
  • Over 300 Substances (and growing)
  • Continually monitored and updated.


Developing the most practical path forward for your product

Biological safety is a continuous process throughout the lifecycle of a medical device.

Scroll to Top