Tiered Hazard Assessment Implementing New Approach Methodologies for PFAS-Free Coatings in a Safe and Sustainable by Design Context

Poly- and perfluoroalkyl substances (PFAS) are widely used in industrial applications due to their functional properties; however, concerns related to their persistence and potential adverse health effects are driving regulatory restrictions and the need for safer alternatives. In response, the PROPLANET project aimed to develop PFAS-free coating solutions within the Safe and Sustainable by Design (SSbD) framework, integrating human health hazard assessment throughout the innovation process.

In PROPLANET, hazard assessment was implemented using a tiered approach across the coating development stages. Initially, existing toxicological information on individual coating components was collected through data mining of safety data sheets and regulatory databases, maily ECHA CHEM, to support the selection of safer substances and identify data gaps. Where relevant information was missing, New Approach Methodologies (NAMs) were applied to address data gaps and support early hazard profiling. In particular, in silico models were developed and applied to assess the mutagenicity of PFAS-free alternatives.

Building on this early screening, in vitro NAMs formed the core of the hazard assessment strategy for candidate coating formulations. A structured battery of assays, informed by Adverse Outcome Pathways, was applied to investigate key toxicological endpoints, including cytotoxicity, genotoxicity, inflammatory responses, carcinogenic potential, endocrine activity, and reproductive toxicity. Whenever possible, PFAS-free formulations were tested in parallel with PFAS-based benchmark coatings.

The outcomes of the hazard assessment informed coating development and supported the identification of candidates with lower hazard potential for further advancement. Overall, in vitro results indicated limited adverse effects for most PFAS-free alternatives compared to PFAS-based benchmarks, although some formulation-specific responses were observed and warrant further investigation. By embedding a tiered, NAM-based hazard assessment within the SSbD framework, PROPLANET supports the development of safer PFAS-free coatings and contributes to the advancement and acceptance of NAMs.