Gamma-valerolactone (GVL) has been known for many decades as an excellent solvent that can now be made from sustainable materials. Although it is praised as very green and versatile in numerous publications, the GVL has never reached the level of a large industrial product. Relevant data on toxicity and biodegradability are also lacking. In this post we present such data. In addition, we are conducting a detailed study based on Hansen Solubility Parameters (HSP) and COSMO-RS calculations to identify harmful solvents that could potentially be replaced by GVL and to suggest a variety of other uses for this substance. Toxicity tests with aquatic plants, bacteria, invertebrates and a vertebrate cell line showed low acute toxicity of GVL to aquatic organisms. In addition, GVL was found to be readily biodegradable, which further strengthens its potential as a “green” solvent. Exact HSPs of GVL have been proposed and used in addition to COSMO-RS calculations to compare its solvent properties with those of classical organic solvents. A similarity between GVL and several aprotic, strongly dipolar solvents, such as the reprotoxic compounds No-Methyl-2-pyrrolidone (NMP) and dimethylformamide (DMF) found. Based on the results, it was found that GVL is of interest as a green solvent in the production of certain polymers or pharmaceuticals, as a cleaning agent in various paint and coating formulations and as a solubilizer in cosmetics, pharmaceuticals or agrochemicals. Together with a very significant drop in prices due to an intended large-scale production in Europe, the data presented should hopefully lead to the surge in use that this green solvent deserves.