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Essential Oils are NOT Essential

essential oils aromatherapy VOCs

Essential oils are used in many fragrances, cleaners, cosmetics, and aromatherapy. They are often sold as a natural alternative to industrial chemicals. Although they are “natural”, are they safe? How do they impact indoor air quality?

A recent study published in the Journal of Air Quality, Atmosphere & Health found significant volatile organic compounds (VOCs) emissions from essential oils. The research published in the paper, “Volatile chemical emissions from essential oils” reports on 24 essential oils including tea tree, eucalyptus, lavender, orange, peppermint, lime, and coconut.

Each essential oil emitted between 20 – 140 VOCs. The most prevalent VOCs were:

  • alpha-pinene
  • Limonene
  • Acetone
  • Linalool
  • alpha-phellandrene
  • beta-myrcene
  • Camphene
  • Ethanol
  • beta-pinene
  • 3-carene
  • Eucalyptol
  • Acetaldehyde
  • Beta-phellandrene
  • Gamma-terpinene
  • M-cymene
  • beta-trans-ocimene
  • Methanol
  • Terpinplene

Of these, perhaps the most concerning are acetaldehyde, acetone, and methanol. All three are chemicals that are regulated by OSHA for occupational exposures.

Does this mean you need to toss out all your essential oils? You will need to weigh the benefit you receive from them (nice fragrance, smooth skin, etc.) with the potential risks with VOC exposure. Your VOC exposure is typically worse doing a manicure, but that is a one-time event. Many people have essential oil diffusers constantly running and often right next to the bed. I remember breaking the heart of a client when our VOC testing showed that elevated levels in her home were mostly due to her beloved essential oil diffuser.

Just because something like essential oil is natural, doesn’t mean that it’s healthy.

Ian Cull

Ian Cull is a nationally recognized expert in the field of indoor air quality. He is the Chief Science Officer of Indoor Science, a company he started in 2004. He speaks around the world on air quality topics and is a training provider of the Indoor Air Quality Association. Mr. Cull is a Licensed Professional Engineer (PE) and Certified Industrial Hygienist (CIH). His degree is in Environmental Engineering from the University of Illinois - Urbana Champaign. Mr. Cull has developed 50 air quality related courses for the IAQA University and is the author of the book, “Fundamentals of Mold Remediation”. In his words… “Besides being passionate about indoor air quality, I enjoy cycling, music, the Chicago Bulls, and having fun with my three kids.”

28 thoughts on “Essential Oils are NOT Essential

    I just had a question for you! I was considering switching to using EO’s in exchange for commercial cleaning products, but I’ve read this information elsewhere and now am not sure what the best thing to do is. Would natural cleaning products like Method be better than using oils in terms of health or are there worse ingredients in those productS?


    I suggest you do some research on cleaning chemistry. Many surfaces just require water and soap (a surfactant) for cleaning. A solvent, “natural cleaner”, or oils may not be necessary for everyday cleaning.

    Thank you for this information. I wish I could share it on my Facebook page and other platforms because many of my friends are really into natural medicine, as I am. However I’m more interested in the truth about essential oils rather than making my homemade oils, ointments and soaps smell irresistible, so people will buy them to use on themselves and their children. Nobody wants to hear this, and their never going to believe someone like me. Again thank you for this information

    My daughter in law started having really bad dizzy spells and actually fainted. We called the paramedics and her vitals were fine, she has also had lots of blood tests which were clear.
    I said to her this problem started when you got the diffuser and started burning essential oils. This resulted in her stopping the use of them, and she is fine now. She believes she was allergic to VOC. I have them now but I am ok with them as I do not have any allergies ha ha perhaps as I am older and better immune system.
    Thought you would be interested to know, makes you wonder how many more people are feeling ill because of this and do not realise.

    Hi. Going through smoky times here in Oregon. Aqi bad outside. Doors & windows are taped and following all the advice about mitigating risk. Putting my essential oils away. What is impact of humidity on indoor air quality? Any other suggestions?

    Humidity can impact indoor air quality. 40-60% is the ideal range, although others say 30-60%. You could also use a HEPA-based air purifier to supplement particle removal. Ones with activated carbon and other sorbents will also help to remove gases.

    Hi Ian, could you please describe HOW a plant turns into a poison during the making of the oils? Teatree and lavender are not admitting VOCs from their flowers in nature. Can you please describe how this transformation happens?

    Plants produce many chemicals- some with the purpose of protecting them from insects or microorganisms. Some of these organic compounds are volatile and thus they are considered VOCs. Heck, even humans give off some VOCs as part of their normal metabolism! Natural doesn’t mean harmless. Many trees produce formaldehyde, a known carcinogen.

    In the making of essential oils, the concentrations of these chemicals may be dramatically increased. So you could have an unnatural concentration of a natural chemical.

    I see you maintain a blog about healthy living… I would be happy to contribute if you do an article about indoor air quality.


    Hi Ian, I’m A health consultant and I help people figure out what sort of environmental poisons they’re exposed to in their lives So they can reduce the impact and create a healthier being. I found this article on essential oils very interesting. how can I get some more information on this? Information like the specific companies that were tested. Often people consider all diffusers “ essential oils” because there are some essential oils in the product. but there are so many products out there with varying degrees of chemicals in them I think it’s important to have more clarity. could you please help me by providing more information detailing the companies that were studied? I would appreciate the assist.
    Thank you for your time.


    I would suggest contacting the authors of the study, which are listed as Neda Nematollahi, Spas D. Kolev, and Anne Steinemann. I was not involved in the study itself.


    Hi, and thanks for sharing the study results. It seems that the VOCs are from additives, though, not from the oils themselves. 100% oils do not have additives. In support of this, I see the list of additives in your article. Those people using 100% oils are not in danger of volatile organic compounds. Would you agree? People should know that a mix of chemicals with a little EO is good for anyone and certainly should not be heated in an enclosed area. Same with candles…never.

    Many of the chemicals listed are the essential oils and not additives. Just because something is natural, it doesn’t make it harmless. I advocate people balancing the benefits and potential harms when deciding about using essential oils.

    Hi! It is my understanding that VOC in essential oils liberate if the diffuse uses heat at low temperature. But the ones that use cold to diffuse oils , don’t liberate VOC.

    Is this true ?
    Thanks ,


    The warmer the oil, the greater the rate of off-gassing VOCs. However, even at room temperature, essential oils will off-gas VOCs to some degree. The smells (vapors) of essential oils are VOCs.

    What is considered a high level of VO’s? You found these oils to be between 20-140 VOC is this high? When weighing the pros and cons I would like to do know this :) Thank you!


    The articles should say that essential oils can emit between 20-140 different types of VOCs. 20-140 is not a concentration of VOCs but rather the number of different volatile organic compounds (VOCs). The health impact of each individual VOC is unique. Some cause problems at relatively low concentrations and others don’t cause problems until they are at relatively high concentrations.


    So glad I found this! I work in a shop that sells soaps heavily scented with essential oils, we often have the diffuser running all day, have essential oil room mists and perfumes constantly being sprayed around the shop by customers, I have begun to suffer frequent headaches and migraines, could this be due to the essential oils? I feel like everyone at the company thinks I’m crazy to suggest it. Hope you can help!

    That would be a good question for a doctor. In a general sense, certain indoor air quality pollutants could cause headaches, but I am not qualified to provide a diagnosis in this case. Anecdotally, I have heard of people getting headaches when entering cosmetic stores.

    I was wondering if there are essential oils out there that do not release VOC, yet still smells good?

    I’m not familiar with any such essential oils but it would be interesting to do a test on several products. If you like an aroma and it isn’t having a noticeable effect on anyone, then you probably don’t need to worry about this. But if you have sensitivities or you are trying to have the best indoor air quality possible, I would steer away.

    No, essential oils do not impact air quality. True and natural essential oils come from nature itself.

    Pollutants like asbestos and radon also come from nature itself. Just because something is from nature doesn’t mean that it is risk-free.

    Like many things, there is a benefit and a risk. Let me not dissuade you too much from enjoying the benefits of essential oils… just be aware of some of the risks.

    Whoa! I am disfusing thieves essential oil, which contains eucalyptus, for 3 days non stop to get rid of mold in a bathroom vanity. On day 1 now. My Young Living distributor said she did this on mold in her mother’s home on a window, but no one lived there. I am in my apartment doing this. The diffuser is not beside my bed, but in my bathroom vanity. Should I stop as this is creating VOCs? Indoor Air did VOC testing for me with toxic paint fumes in another apartment. Christa

    If you live in an area with good outdoor air quality, I would recommend outdoor air ventilation over adding something into the indoor air.

    Essential oils are being marketed in ways that have increased their per capita usage to levels never seen before. Any consequences from long term exposure at these levels won’t show up till years later. By then it will be too late. We are in the guinea pig phase of a great human experiment. In the end, there is no substitute for clean air.

    Thanks Ian…another colleague of mine told me about this…this past week. Kind of scary as I’ve been a regular user of EO’s for years. Thanks for sharing on your blog.