However, there has been recent evidence that essential oils can be toxic to cats (whether inhaled, applied to the skin, or taken internally). This is because a cat’s liver is unable to correctly metabolise the various compounds of essential oils. For more information, see the external link further down this page, under Sources and Related Links.
Is basil essential oil toxic to cats
No, in my opinion, basil essential oil is not toxic to cats, but should be used as if they are a small child. It can be irritating to sensitive skin and eyes just like humans. But basil is safe to use around cats in normal methods and amounts.