IVL Swedish Environmental Research Institute

ProScale is a regulatory-aligned, screening-level chemical footprinting method for assessing the potential human toxicity and ecotoxicity impacts of substances, materials, and products throughout their respective life cycles. The ProScale Suite comprises four complementary modules: ProScale for Workers (ProScale-W), ProScale Service Life (ProScale-SL), ProScale Environment (ProScale-E), and ProScale for Indirect Human Exposure (ProScale-IE). This guidance document presents the ProScale methodology, including the key elements that constitute a ProScale score and the four principles underpinning the method: i) utilize hazard and exposure information already generated within regulatory practice, ii) be compatible as a screening-level tool for Safe and Sustainable by Design (SSbD) applications, iii) adopt a conservative approach to deal with data gaps and uncertainties and iv) bridge risk assessment (RA) and life cycle assessment (LCA) paradigms. ProScale scores are derived by combining hazard and exposure information and translating these into an LCA-compatible format through system-level parameters.

Exposure information is based on methodologies recommended in the European Chemicals Agency (ECHA) Guidance on Information Requirements and Chemical Safety Assessment (CSA) under REACH (EU Regulation No. 1907/2006). ProScale-W and -SL use the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) Worker and Consumer Targeted Risk Assessment (TRA) tools, respectively, whereas ProScale-E and -IE estimate potential exposure using Environmental Release Categories (ERCs) and Specific Environmental Release Categories (SPERCs). All modules share a common hazard basis derived from substance classifications under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and the EU Regulation No. 1272/2008 on Classification, Labelling and Packaging of substances and mixtures (CLP). Human-health hazard classifications are applied in ProScale-W, -SL, and -IE, while environmental hazard classifications are applied in ProScale-E. The hazard information from GHS/CLP is modified using hazard modifiers to account for substance potency. This guidance also provides a comprehensive overview of the updates, revisions, and additions introduced in ProScale 2.0 compared to ProScale 1.5.