Nanotechnology is the manipulation and control of matter in the nanoscale (size range from approximately 1 nm to 100 nm) in order to make use of unique size- and structure-dependent properties which are different from those associated with individual atoms or molecules or with bulk materials.
The potential benefits of nanomaterials are considerable, and include applications as diverse as agriculture, medicine, energy, information technology, water and wastewater treatment, remediation of environmental pollution, aerospace, construction and chemical industries; as well as consumer products, including textiles, cosmetics and foods. There are already over 1,000 nanotechnology-enabled consumer products¹.
Specific regulation for nanomaterials, to ensure that they do not pose a risk to either the environment or human health, is beginning to be enacted by regulatory authorities in North America, Europe and elsewhere. These often have provisions for additional data requirements, labelling or nanomaterial-specific risk assessment.
wca has wide-ranging experience working with both government and industry clients on the hazard and risk assessments of nanomaterials:
- We have reported to UK Government on whether current ecotoxicity guidelines and frameworks are fit for purpose when testing nanoparticles.
- We produced a comparative assessment of the ecotoxicity of silver ions and silver nanoparticles to support derivation of a silver Environmental Quality Standard under the Water Framework Directive.
- We ran a workshop in 2007 with international participants (regulators, academics and industry) to develop a framework for environmental testing of nanoparticles.
- We have undertaken a review of the regulatory legislation and guidance on the risk assessment of nano materials for our clients.
- We are preparing a REACH registration dossier to cover a nano form of a substance.
- We have contributed to an article in Ecotoxicology, discussing practical considerations for conducting ecotoxicity test methods with manufactured nanomaterials.
Nanotechnology under REACH
On the 18th of October 2011 the European Commission (EC) adopted theRecommendation on the definition of a nanomaterial. According to this Recommendation a “Nanomaterial” means:
- A natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50 % or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm – 100 nm.
- In specific cases and where warranted by concerns for the environment, health, safety or competitiveness the number size distribution threshold of 50 % may be replaced by a threshold between 1 and 50 %.
- By derogation from the above, fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm should be considered as nanomaterials².
Although the REACH regulation does not make any specific provision for nanomaterials, the Commission has confirmed that, as REACH makes no reference to the size of materials, nanoparticles are substances and therefore subject to the provisions of REACH. However, there are unique considerations that must be addressed when implementing REACH for nanoparticles, some of which have been addressed by the RIP-on programmes (1: Substance Identification; 2: Information Requirements; 3: Chemical Safety Assessment) and the publication by ECHA of nanomaterial-specific annexes to the endpoint specific technical guidance. Specifically, substance identification, testing or non-testing strategies for fulfilling nanomaterial data requirements may require the modification of standard methods, or necessitate the additional characterisation of test materials (i.e. particle size and particle size distribution). Properties and behaviours of nanoparticles can change in conjunction with parameters such as particle size or particle coating (surface treatment), which requires careful consideration. Nanomaterial properties can also be influenced by changes in the physico-chemical properties of environmental (fresh or marine water) or test media, with particle size often varying as a result of aggregation or agglomeration of primary particles in aqueous media.
We have experience working with clients on the registration of nanomaterials. We have advised them on the best approach for the registration of nanomaterials (i.e. the preparation of novel dossiers or updating existing “bulk” dossiers) and suitable robust approaches for addressing data requirements, including non-testing approaches such as read-across. Our expertise on ecotoxicity testing of nanomaterials enables us to critically review the available literature and identify reliable data sources.
² Handy RD, van den Brink N, Chappell M, Mühling M, Behra R, Dušinská M, Simpson P, Ahtiainen J, Jha AN, Seiter J, Bednar A, Kennedy A, Fernandes TF, Riediker M (2012) Practical considerations for conducting ecotoxicity test methods with manufactured nanomaterials: what have we learnt so far? Ecotoxicology, vol. 21, pp. 933-972