The ease of synthesis, affordability, and adaptability of deep eutectic solvents (DESs) across a wide range of industries, including the chemical, biological, and material sciences, have made them attractive substitutes for conventional solvents. Variability in toxicity associated with their formulations and exposure situations throws into question the generalization that they are more biodegradable than traditional solvents. Even though DESs are less harmful than ionic liquids (ILs), they provide serious biological and ecological hazards. The toxicity profiles of DESs are reviewed in this chapter, with a focus on how they interact with various living things. These interactions depend on the composition, concentration, and interactions between the various components. With information on their breakdown pathways and the part that their structural elements play in determining environmental impact, their biodegradability is also being discussed. This chapter will also cover some of the most popular analytical metrics for evaluating greenness and their intended usage.