When working with essential oils, it is absolutely imperative that you have an understanding of the safety issues involved. Essential oils are much safer than over-the-counter drugs and chemicals, but it’s still important to know what you’re doing and know that some concerns exist. There are dozens of books about essential oil safety, so we won’t get into it too deeply here.
Aromatics International has a page devoted to Essential Oil Safety. We recommend browsing it, and if you use oils regularly you may want to look into one of the great books on the topic.
Internal Use
For instance, some practitioners and teachers recommend internal use. Internal use requires knowledge of Anatomy, Physiology, and the chemistry of essential oils. Oils should be used via the skin and inhalation only unless someone understands the potential interaction of drugs and essential oils, knows the safe oils to use (the safety issues are different for skin and internal use), and knows the right dose and route of application appropriate for internal use. Internal use also requires an understanding of pharmacokinetics–effects of the body on the oil, how the body metabolizes the oil and eliminates it, and what organs might be effected. It sounds complicated because it is—and that’s why we don’t widely recommend internal use.
When using the oils on the skin at a 1-3% dilution or through inhalation, most safety concerns are just not relevant. The oils are very safe. However possible skin irritations can occur if an oil is old/oxidized.
Phototoxic Concerns and Irritation
Certain oils like Peppermint and Lemongrass can be highly irritating. Other oils, like Lemon and Grapefruit can be phototoxic. If one were to use these oils inappropriately it could cause skin burns and in some instances permanent discoloration to the skin. As you can imagine, anyone using essential oils in bath/skin products or therapeutically needs to be aware of these concerns.
Use on Animals
Essential oil use on animals needs to be supervised by a vet and Aromatherapist to formulate correctly. Essential oils should NOT be used on small animals, cats, birds or small dogs. The results can be dangerous for your pet. Best results are with large animals like horses or cows.
Babies
Never use essential oils on the skin of babies under one year of age. Even up to ages three or four you want to be very cautious and only use mild oils at 1%. If you would like to use oils, you can diffuse the oils into the room at any age!


