Are doTERRA Essential Oils safe? Safe enough to be used in one of the busiest Hospital Emergency Rooms in the nation. For over a year, the doTERRA emotional oils have been diffused in the Vanderbilt Hospital Emergency Room to help the staff feel better emotionally in their extremely stressful environment. Before the use of doTERRA essential oils, 41% of staff members felt work-related stress very often. After the use of doTERRA essential oils, only 3% felt work related stress very often. 84% of the staff strongly agree that the use of doTERRA essential oils creates a better work environment!