February 2015: The World Health Organization (WHO) Chemical Risk Assessment Network has issued updates on network projects including: review of chemical-specific adjustment factors (CSAF) in risk assessment; and assessing immunotoxicity risk associated with exposure to nanomaterials.

According to the latest newsletter from the Network, the WHO Collaborating Centre on Water and Indoor Air Quality and Food Safety at NSF International, through the WHO Chemical Risk Assessment Network, is leading a working group to review the strengths, limitations, and research needs in the application of chemical-specific adjustment factors (CSAF) in quantitative risk assessment. The working group is reviewing and summarizing the state of the science since the 2005 introduction of the International Programme on Chemical Safety (IPCS). Research involves the identifying examples of assessments where data-derived inter- and/or intra-species factors were considered or adopted. The manuscript is expected to be available for review in 2016.

The newsletter also highlights a new initiative on nanoparticles. Nanoparticles interact with components of the immune system more than any other organ, and the potential effects of nanomaterials are not often tested for risk assessment purposes within regulatory frameworks. In response to this, the WHO Collaborating Centre for Immunotoxicology and Allergic Hypersensitivity at the National Institute of Public Health and the Environment in Bilthoven, the Netherlands, is developing environmental health criteria to assess the risk of immunotoxicity associated with nanomaterials.

The WHO Chemical Risk Assessment Network is a voluntary collaborative initiative to improve chemical risk assessment globally by facilitating interaction between institutions on chemical risk assessment issues and activities, to ensure better assessment of risks to human health from exposure to chemicals. [Publication: WHO Chemical Risk Assessment Network Newsletter]