Sources and methods

The SSbD SSG web app performs a bespoke solvent selection analysis based on user input, combining the established solvent selection guide style with modern principles from the Safe and Sustainable by Design framework.

Safe and Sustainable by Design

Safe and Sustainable by Design (SSbD) is a framework to encourage the substitution of hazardous substances with superior alternatives that reduce risk and improve sustainability. Guidelines have been issued in 2022 and then 2026 [1]. It is a voluntary exercise supported by the European Commission. One key aspect of SSbD is a 'safety and sustainability assessment'. It is this 'safety and sustainability assessment' that is the inspiration for SSbD SSG. The health and safety aspect is based on risk characterisation ratios, which compares exposure to Occupational Exposure Limits. Exposure has been determined using the same principles as the ECETOC Targeted Risk Assessment tool [2]. The risk to the environment is based on environmental fate and the hazards arising from chemical releases. Environmental impacts (climate change and freshwater use) are also computed. The user can also predict the reaction conversion in different solvents. This requires prior knowledge of the solvent effect governing the kinetics of the reaction. SSbD SSG has preset reaction data for which the conversion at a given time can be calculated. The user can add their own reactants for Green Chemistry metrics.

References

References to physical property data are given in the Database section. Exposure is taken from 'ECETOC TRA version 3: Background and Rationale for the Improvements' [2]. The energy use of processes was derived from the model of Piccinno et al. (2016) [3]. Predicted conversions are obtained using the Variable Time-Normalised Analysis of Burés (2016) [4].

Calculated properties

Some predicted data is used in SSbD SSG. Calculated physical property data is used sparingly, mostly for water solubility, vapour pressure, bioconcentration factor and atmospheric halflife when experimental data was not available. The Open (Quantitative) Structure-activity/property Relationship App (OPERA) was used to obtain these values (as indicted in the Database section) [5]. Hansen Solubility Parameters were calculated using the method of Mathieu (2018) [6]. Environmental partitions between air, water, soil and sediment were calculated using the procedure of Mackay et al. (1992) [7]. Antoine coefficients were calculated with CoolProp (Bell et al., 2014) [8]. Unknown specific heat capacity values obtained with the method of Růžička & Domalski (1993) [9].

Disclaimer

This tool advises appropriate solvent selection based on a combination of experimental data, predicted data, and modelled scenarios. The actual risk to health, safety and the environment depends on conditions and practices that may not be precisely represented by this tool. SSbD SSG does not replace existing safety protocols and risk assessments. Hazards posed by reactants, catalysts etc. are not included in this web app. SSbD SSG was developed with Claude Code (Anthropic's Claude Sonnet 4.6 AI model), which assisted with JavaScript implementation, SVG rendering, and logic porting from Python. The SSbD guidance issued by the European Commission is subject to change and may diverge from the approach used in this tool. Email james.richard.sherwood@gmail.com with questions and comments.

Acknowledgement