The OECD’s Working Party on Manufactured Nanomaterials (WPMN) was established in 2006 when engineered manufactured nanomaterials (EMNs) started to be used in a variety of commercial applications. Several concerns were raised both by scientific community and authorities on how they should be addressed in the regulatory context and, especially, how they should be assessed in order to identify potential risks for human health and environment. Hence, its main objectives were to promote international co-operation in the identification of the key safety aspects of ENMs and to assist member states in their efforts in hazard evaluation of EMNs [].

Properties of materials on the nano-scale, typically within the range of 1-100 nm in at least one dimension, can be different from those on a larger scale as for example, increased surface charge and reactivity. In practical terms, EMNs biological effects do not depend only by the chemical composition but also by their physical and chemical characteristics. These novel characteristics offer possibilities for new exciting applications in a broad range of sectors such as: medicine (e.g., drug delivery by nanocarriers or liposomes), environment (e.g., waste-water treatment with carbon nanotube filters), energy production (e.g., solar cells using silicon nanocrystals), and consumer products (e.g., food, cosmetics).

Conversely, due to their specific properties, EMNs may require additional testing beyond the standard panel of tests used for traditional chemicals, to ensure that impact on human health and environment is fully understood. Evaluation of specific regulatory requirements dealing with EMNs potential risks is also needed.
After about six years of work, WPMN has come to the conclusion that completely new testing approaches for ENMs is not necessary and the traditional procedures for testing and assessment chemical safety (i.e., OECD Testing Guidelines, TG) are in general appropriate for assessing the EMNs safety. Nevertheless, intrinsic properties of ENMs have to be taken into account to eventually accommodate TGs accordingly (Recommendation of the Council on the Safety Testing and Assessment of Manufactured Nanomaterials [C(2013)107], adopted in September 2013 [C/M(2013)16].
To date, OECD continues to review existing TGs to identify and implement the necessary changes required for their application to EMNs.

Since 2006, more than 100 public reports have been produced by WPMN covering different methodological and safety aspects of ENMs. Reports are available at: date five working groups are active within the WPMN and a panel of national experts participate to their activities:

  • testing and assessment
  • exposure measurement and mitigation
  • risk assessment and regulatory programmes
  • safe(r) innovation approach (SIA)
  • advanced materials

As a future challenge, WPMN will continue to anticipate emerging safety issues resulting from the new nano-innovative materials that are being developed. Because of this rapid innovation, a gap can arise between technological innovations and development of suitable risk assessment tools. A way to minimise this gap is the development of ‘Safe(r)-by-Design’ approach according to which industry try to reduce uncertainties and risks for human and environmental safety moving the risk assessment in the early phase of the innovation process covering the whole innovation value chain. The WPMN will strongly pursue this approach.