Ionic Liquids / Non-Volatile Solvents
When salts can be designed to perturb their crystal structure adequately such that they are a liquid at room temperature, they are known as room temperature ionic liquids RT-IL). These liquids have been demonstrated to be effective solvents in a wide range of applications all while having negligible vapor pressure. This is important as lack of vapor pressure avoids one of the most concerning routes of exposure for most volatile solvents, that of respiration. Another major concern with traditional solvents is how they impact the atmosphere. With RT-IL, this type of atmospheric transport is not possible.
While the lack of vapor pressure is an elegant attribute for this class of solvents, it is also critical that these solvents are designed for reduced toxicity as well.