Many people like myself received a diffuser either for Christmas or bought one for their essential oils this past year. Many people also have cats. And many people, like me, assume essential oils, being natural and from the earth, are harmless, since they are used for healing. And like many indoor plants, oils can be harmless but can actually be downright deadly to cats. This is where we need to stop assuming and it was time to do some homework.

Toxic Oils for Cats

Typically once essential oils are discovered, people begin collecting different types, purchasing kits of mixed blends with may different oils in each bottle. Also, among this trend – which is how I would describe the sudden rise of usage, even though oils have been diffused for years – comes sketchy oils. These can be made by companies not sourcing ingredients correctly and/or using cheap fillers. As a result, consumers must be careful of these brands and strive to source from only reperable sources. After all, you or Mittens wouldn’t want to actively breathe in chemicals?

How do oils work?

After being absorbed by the skin, they then metabolize by the liver. It’s this aspect that makes cats and oils not get along. Cats have a more difficult time metabolizing oils. It all comes down to their liver, where they do not possess glucuronyl transferase, a liver enzyme. Without this, they are unable to eliminate certain toxins from their body, and this includes essential oils. After time and exposure, these toxins build up and can cause serious damage with symptoms not surfacing for weeks, months, or even years.

Toxic Essential Oils to Cats

Many essential oils contain phenolic compounds, which cats are highly sensitive to. Basically, the higher the concentration of the essential oil (such as one not diffused with carrier oil), the higher the toxicity. The higher the concentration of the essential oil (i.e. 100%), the greater the risk to the cat. Hot oils like cinnamon, nutmeg, and thyme contain the highest levels of phenol and can be the most offensive to cats.

What is a phenol? Time to get sciencey. “Also known as carbolic acid, phenol describes a group of aromatic organic compounds consisting of a phenyl group bound to a hydroxyl group. Although similar in molecular structure to an alcohol, phenols have their hydroxyl group attached to an aromatic hydrocarbon ring, whereas an alcohol’s hydroxyl group is bound to a saturated carbon atom.”*

Are Essential Oils Safe for Cats

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Certain oils can also negatively affect humans. While I diffuse many single oils, like lavender and peppermint, I instantly get a headache with any oil blend (usually an orgy of oils altogether). A key component is the purity of the oils too. As mentioned above, if the quality of the oils are poor, they are infinitely more dangerous than pure oils. Today, most diffusers produce much more saturated scents. If people can be sensitive to these smells, imagine how assaulting these scents can be to Mittens.

I know, I know, now you are left with a bunch of toxic oils and you don’t know what to do with them. You can always use these oils in a room with a closed door, such as a bathroom when taking a shower. Also, if possible, you can take your diffuser to work and use those oils. This is what I did, and I sleep so much better at work now.

If anything, please remember:

-Avoid hot or toxic oils. If you need to diffuse for health reasons, provide air circulation and avoid diffusing in areas where cats primarily reside (ie, your bedroom if they sleep next to you at night).
-Diffuse safe oils no more than a few hours each day, allowing rest periods for the scent to dissipate. Safe oils include Frakensense, Lavender (100% pure oil only), and Myrrh. -Never apply oils directly to your cat unless specified by a vet.
-If you apply oils to your hands, wash before petting Mittens.
-If you have been diffusing toxic oils for a while, keep a close eye on your cat, watching for symptoms of lethargy and monitoring eating/drinking and the litter box for signs of distress.
-Call the ASPCA line or your vet with questions about oils.
-When in doubt, don’t diffuse it.

*Info from, a very helpful site for all things pets and toxic chemicals.