During the solution-mixing process, staff might easily select an incorrect amount of a drug or an incorrect type or amount of solvent, without realizing they’ve done so. The solution would then be mixed incorrectly, but the label would indicate the intended dose and solution, making the error invisible to the person administering the drug. Human factors studies have shown that the risk of such errors is especially high when workers are busy, distracted, tired, or working in an environment not designed for safety. Using pre-mixed solutions reduces the possibility of an adverse drug event due to a mixing error. Pre-mixing also saves time for pharmacy and nursing staff.