The answer to the question in the title is yes and no as the response depends on variable factors. Please read on.
My research indicates that there is a potential problem with essential oil diffusers generally in regards to pets. The information comes from the respected ASPCA Animal Poison Control Center and Cats Protection. Essential oil diffusers are more popular than in the past. The Happy Tails Emergency Veterinary Clinic paints a very black picture about the dangers of essential oils but their focus is on the concentrated form. But if the concentrated form of some essential oils can be toxic to pets it does support the conclusion that the diffused oils (diluted) are not entirely safe either.
Happy Tails state this: According to the ASPCA Poison Control Center these are the top 10 most toxic essential oils for cats:
- Wintergreen oil
- Peppermint oil
- Pine oil
- Eucalyptus
- Clove oil
- Tea tree/Melaleuca oil
- Citrus oil or those containing d-limonene
- Ylang Ylang
- Cinnamon oil
- Pennyroyal oil
Cats Protection says these essential oils are the most toxic to cats:
- cinnamon oil
- citrus oil
- clove oil
- eucalyptus oil
- lavender oil
- pennyroyal oil
- peppermint oil
- pine oil
- sweet birch oil
- tea tree oil
- wintergreen oil
- ylang ylang oil
Concentrated and dilute versions
But the important point is that these oils are toxic in neat, non-diluted form to cats and dogs but when very diluted and diffused into the environment they are not hazardous to pets. BUT the ASPCA provides cautious advice on using them. That’s important particularly as keeping cats indoors is popular too.
RELATED: Will steaming fresh eucalyptus branches in my shower harm my cats?
Variety of formulations
They can’t provide a clear black-and-white answer on their toxicity as it depends on concentrations and the variety of oil.
For instance, at one end of the scale there is tea tree oil which due to variability in concentrations and formulation may be toxic and is best avoided.
Care handling concentrates
Cats should not get the concentrated liquid of any essential oil on their paws as they’ll ingest it. Fastidious self-grooming makes the domestic cat vulnerable to chemicals in the environment.
Basic advice
For all diffused essential oils, the ASPCA advice is:
“Using an oil diffuser for a short time period in a secured area — one that your dog or cat cannot access — is not likely to be an issue.”
That is quite cautious advice and it might surprise some cat owners who like essential oils. It may encourage them to change what they are doing.
Shower diffusers
In the shower the diffused particles are carried on water droplets. Perhaps this makes the product more effective. Some cats like to join their caregivers in the shower room or in the shower itself e.g., the wild cat hybrids. This combination may make the cat more vulnerable to the potentially toxic effects of essential oils.
Beneficial to humans
Essential oils are seen by afficionados as a remedy for a range of maladies such as anxiety, nasal congestion (sinusitis), sore muscles and skin conditions for example.
Conclusion
In concentrated form essential oils are an actual or potential danger to pets, some more so than others. In diffused (dilute) form there are probably safe but as the ASPCA say they should still be used with some caution. The strong indication is that this popular product is not well-suited to the domestic cat. This is interesting as the physiology of the domestic cat and human is similar. I wonder if humans should rethink the use of essential oils especially if they live with an indoor cat?
Postscript
I sense that there is a P.S. here. There is an increase in the number of full-time indoor cats to keep them safe from outdoor hazards – road traffic and predators (in the USA and other countries). As the goal is to keep indoor cats safe, diffusing potentially slightly hazardous chemicals into the indoor environment where there are trapped may be unwise. It certainly might undermine the goal.