Is it safe to run an essential oil diffuser at work in a closed office?
Avoid it in shared closed offices. Diffusers add VOCs and particles to air other people breathe.
What is in it
Essential oil diffusers put tiny droplets and vapors into indoor air. Tea tree, citrus, eucalyptus, and cinnamon oils contain terpenes and other volatile organic compounds, also called VOCs.
In a closed office, other people do not get to opt out. That matters for coworkers with asthma, migraines, pregnancy, fragrance sensitivity, or simply a need for unscented air.
What the research says
A 2025 Journal of Occupational and Environmental Hygiene study measured VOC and particle emissions from tea tree oil diffusers. Total VOC levels rose above background by 1 to 2 orders of magnitude. A heat diffuser produced higher terpene VOC levels than an ultrasonic diffuser, and several compounds exceeded long-term derived no-effect levels in that setup.
This was a pilot simulation with tea tree oil. It still supports a workplace rule: skip shared diffusers unless everyone has agreed. If scent is personal, keep it personal. If odor is the problem, use ventilation or filtration instead of adding fragrance to the air.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Volatile organic compound and particle emissions from the use of tea tree oil in essential oil diffusers. | J Occup Environ Hyg | 2025 |