Chemical mixtures: help us define ‘MixTox’ before work starts

People, animals and the environment can be exposed to multiple chemicals from a variety of sources. EFSA is launching a ground-breaking initiative to propose methods for carrying out risk assessment for this complex issue. We are calling on stakeholders from science and civil society in Europe and beyond to help shape this work before it starts.

Building on recent international developments and previous work at EFSA on pesticides and contaminants, our scientists have started to develop new approaches for assessing risks to humans and the environment from exposure to multiple chemicals in the food chain: “chemical mixtures” and their “cocktail effects”.

EFSA is already developing methods to assess combined toxicity for groups of pesticides and contaminants and for compounds with multiple sources of exposure (e.g. dietary plus non-dietary).

Dr Tobin Robinson, head of emerging risks at EFSA, said: “Understanding how combined chemicals behave is complex and the number of combinations is potentially infinite. So our goal is to focus on developing practical frameworks and methodologies that help us to assess the combined toxicities of chemicals in different areas of risk assessments relevant to EFSA.

“Ultimately, to help safeguard Europeans and the environment, these methods need to support and inform risk managers in their decision-making,” he added.

What is “MixTox”?

EFSA’s Scientific Committee has laid the foundations for this multi-year project – called MixTox – by setting up a working group to develop guidance aimed at harmonising methodologies for assessing human and ecological risks resulting from exposure to multiple chemicals. EFSA is also developing new scientific tools for modelling combined toxicity through joint research projects involving several institutions.

What have we done already?

This development builds on several years of preparatory work by EFSA and its European and international partners. In 2013, EFSA launched a cumulative assessment group methodology for pesticides and completed a review of international frameworks dealing with human risk assessment of combined exposure to multiple chemicals. In 2015, EFSA hosted top experts from around the world at a scientific colloquium on this topic. Data collection on combined toxicity for animal health and ecological risk assessment has been completed and further analysis is on-going. (For more background see our new topic on chemical mixtures.)

Have your say now

Achieving this goal will take several years from collecting data, to developing tools and bringing together scientific expertise and regulatory authorities in Europe and beyond. We are therefore calling on scientists, scientific advisory bodies and civil society to support and contribute to this work now.

This consultation on the scope of this work (the terms of reference) aims to gather your initial insights and perspectives on EFSA’s proposed approach. We would also like to hear about any similar plans or initiatives underway that would allow us to work towards a common goal.

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