NCEC led peer-reviewed paper highlights the ecotoxicological effects of chemical mixtures

NCEC led peer-reviewed paper highlights the ecotoxicological effects of chemical mixtures
13 April 2021

The National Chemical Emergency Centre (NCEC), part of Ricardo, is pleased to announce that one of its environmental chemistry experts is the lead author of a peer-reviewed paper on the ecotoxicity of chemicals and the risk they pose to aquatic invertebrates. This demonstrates NCEC’s ecotoxicology expertise in a regulatory context and highlights the growing concern over chemical mixtures and persistent, mobile and toxic (PMT) chemicals in the environment.

Many regulations require an assessment of the ecotoxicological endpoints to be made before a chemical is registered and approved for use. Under the EU’s Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation, ecotoxicity testing is a requirement for all substances manufactured or imported into the European Union (EU) in amounts of 1 tonne or more per year. The study, conducted by Megan Griffiths, Regulatory Ecotoxicologist at NCEC, applied the methods of some of these tests to investigate the ecotoxicity and risk of alkaloids to the aquatic invertebrate Daphnia magna. The full peer-reviewed paper can be viewed here.

The paper highlights the discrepancy between single chemical exposure experiments and the risk of chemical mixtures in the environment, as well as the general need for better quality information on ecotoxicity and environmental fate properties for the regulatory assessment of chemicals. These two issues have garnered much attention in recent years, with regulators now taking action set to address them.

How does ecotoxicity data affect chemical organisations?

Ecotoxicity data underpins the hazard and risk assessment of substances. It is used for Classification, Labelling and Packaging (CLP) Regulation ((EC) No 1272/2008); persistent, bioaccumulative and toxic or very persistent and very bioaccumulative (PBT/vPvB) assessments; and calculation of predicted no-effect concentrations (PNEC) and derivation of environmental quality standards (EQS). In particular, PBT/vPvB assessments can have far-reaching implications on the labelling and use of biocidal active substances, plant protection products, human and veterinary medicinal products, and chemical substances manufactured in or imported into the EU in amounts of 10 tonnes or more per year. Substances identified as PBT under REACH are classified as substances of very high concern (SVHC). Therefore, they are subject to severe restrictions on their use and are likely to be phased out altogether. A substance can meet the toxicity criteria if the long-term, no-observed effect concentration (NOEC) or concentration causing 10% effect (EC10) for aquatic organisms is less than 0.01 mg/l. The use of expert input from NCEC can help enable you to conduct tests to a high standard or provide robust scientific justifications as to why they can be waived, which is critical to generate appropriate regulatory outcomes for chemical products.

If your substance(s) have already passed the PBT/vPvB assessment, they may meet the criteria for a new forthcoming SVHC class. As part of the Green Deal, the European Commission launched a Chemicals Strategy for Sustainability Towards a Toxic-Free Environment. This includes a proposal to amend Article 57 of REACH to include the following in the SVHC list in 2022:

  • Endocrine disruptors.
  • Persistent, mobile and toxic (PMT) substances.
  • Very persistent and very mobile (vPvM) substances. 

While the specific PMT/vPvM criteria are yet to be released, these regulatory developments will cause new challenges for industry and put increasing pressure on the need for high-quality, reliable environmental fate and ecotoxicology data – and NCEC can support in this process. 

The EU’s chemicals strategy for sustainability also includes an action to introduce a mixture assessment factor (MAF) to risk assessments under REACH to address potential exposure to unintended mixtures in the environment. The risks posed by incidental mixtures of chemicals in the environment are likely to be greater than those determined by the current practice of assessing chemicals individually. Also, potential synergistic effects of chemical mixtures, a mechanism explored in the peer-reviewed paper, remains a concern. The MAF may help to address this issue in risk assessments by applying an additional safety factor. 

While intended to promote the safety of humans and the environment, the forthcoming changes under the EU’s chemicals strategy for sustainability will make an already complex regulation harder to navigate and comply with. NCEC’s team of environmental chemistry experts can guide you through the process of ecotoxicity and environmental fate tests and help to design, monitor and evaluate them to support you with regulatory compliance. They can also apply non-standard testing approaches (such as quantitative structure-activity relationship (QSAR) and read-across) and identify data requirements that can be waived to reduce unnecessary animal testing, time and cost.

If you have any questions about the ecotoxicity testing of chemicals or any other REACH regulatory queries, please contact us at [email protected]. Alternatively, please use the form on the right hand side so that we can provide you with the expertise that you need to support your products and improve regulatory outcomes for your business.