Expansion of a Paints and Coatings Solvent Guide: Combining Solvent Guides and Hansen Solubility Parameters for Greener Solvent and Solvent Mixture Selection

A substantive update to the 2024 paints and coatings solvents guide, scoring an additional 40 solvents, including those used as strippers, has been provided. The ranking of alternative solvents and solvent mixtures based on sustainability (or other) scores and Hansen Solvent Parameters (HSP) has been facilitated through modification of Albrecht and Strube's 2025 software. Two examples of scoring approaches are exemplified. Circle diagrams, showing a range of possible solvent mixtures as alternatives for a given solvent (or solvent mixture) have been developed and exemplified for two key solvents where there is particular interest in replacement, dichloromethane and N-methyl pyrrolidone. The nature of solvents and solvent mixtures required to map HSP space using both pharmaceutical and paints and coatings specific solvent lists has been plotted, highlighting under-served areas of solvent space for future research.