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Green chemistry requires a metrics system that is comprehensive by the criteria included and simple in the application at the same time. We propose the application of multicriteria decision analysis for comparative greenness assessment of organic synthesis procedures. The assessment is based on 9 criteria (the reagent, reaction efficiency, atom economy, temperature, pressure, synthesis time, solvent, catalyst and reactant) for which data points are easily extractable from synthesis protocols. The criteria are given weights by two experts to differentiate their relative importance. Two datasets are created, one of the procedures for benzoic acid synthesis, the second one of procedures for γ-valerolactone synthesis. In both cases, the greenest procedure is identified and the remaining ones are ranked according to their greenness. The proposed assessment procedure incorporates more assessment criteria than product/waster ratio mass-based metric and is much less tedious than the application of life-cycle assessment.

The impact values for the environmental emissions of 52 solvents are estimated and expressed in monetary units. The impact values of solvents present in the air are calculated on the basis of 13 impact indicators and additional 2 impact indicators for solvents present in water. These impact values are weighed with the results obtained with a multi-compartment distribution model, allowing the calculation of the fraction of solvent emitted to the environment present in each of the compartments. The results show that the impact values of solvent emissions are in the range of 0.7–1179.51 $ L−1, with a mean value of 20.69 $ L−1, expressed in USD2019. These impacts are considerably lower for short-chain aliphatic hydrocarbons, alcohols, ethers, aldehydes, ketones, and esters. High impact values are obtained for long-chain aliphatic hydrocarbons, aromatic hydrocarbons, terpenes, and an extremely high value for carbon tetrachloride. Monetary values calculated to assess the solvent emission impact have the advantage that they are quantitative and easily applicable.

A novel procedure for assessing the environmental risk related to solvent emissions has been developed. The assessment of risk was based on detailed hazard and exposure investigations. The potential exposure related to different environmental phases was calculated using a basic multimedia model, which gives the percentage distribution of solvent in environmental compartments as a result. Specific hazards – toxicological, environmental persistence or photochemical ozone creation data have been assigned to each compartment. The environmental distribution of solvents gives the weights applied in the multicriteria decision analysis, which was applied to obtain the full ranking of solvents. The results show that alcohols and esters can be considered as low environmental risk solvents, whereas chlorinated solvents or aromatic hydrocarbons are the most problematic. The assessment procedure holds promise for solvent selection during process design as well as in finding alternatives to hazardous solvents used in existing processes.

The study reported herein is aimed at the greenness assessment of 267 derivatisation agents that are frequently applied in analytical chemistry and related disciplines. Multicriteria decision analysis allowed obtaining three rankings of derivatisation agents applied in liquid chromatography, gas chromatography and chiral analysis. The criteria of assessment included the safety information obtained from material safety data sheets and physicochemical and environmental parameters predicted with relevant models. As for some of the agents predicted data were not available, these agents were assessed with a smaller number of criteria, within the ranking of low confidence. The results of the study will help to apply greener derivatisation agents, wherever the green chemistry principle of avoiding derivatisation cannot be fulfilled.

The study offers a multivariate statistical analysis of a dataset, including the major metrological, “greenness” and methodological parameters of 43 analytical methodologies applied for aldrin determination (a frequently analyzed organic compound) in water samples. The variables (parameters) chosen were as follows: metrological (LOD, recovery, RSD), describing the “greenness” (amount of the solvent used, amount of waste generated) and general methodological parameters (sample volume, time of analysis, injection volume) and scores of greenness assessment with NEMI and eco-scale. The results of the study show that all analytical methodologies have been grouped into three clusters. The first one consisted of “non-green” LLE and SPE methodologies and the other two consisted of solventless or virtually solventless methodologies. The NEMI and eco-scale scores are well correlated, which indicates the similarity between these two assessment scales. A self-organizing maps technique is not feasible for easy and quick labeling of analytical methodologies in terms of their greenness. However, the multivariate analysis of analytical methodologies can give information about clustering of methodologies to “green” or “non-green” groups and some extra information about relations between objects inside clusters of interest.

Correction for ‘A solvent selection guide based on chemometrics and multicriteria decision analysis’ by Marek Tobiszewski et al., Green Chem., 2015, 17, 4773–4785.