Essential oils safety
These safety guidelines are not a complete safety reference for the proper use of essential oils. When in doubt, consult your physician and/or a qualified and trained aromatherapy practitioner.
Essential oils should never be used undiluted on the skin. There are instances when experienced aromatherapy users and practitioners make exceptions to this precaution, but only once significant essential oil knowledge is gained should you ever attempt to apply an undiluted oil on the skin. Lavender and tea tree are listed by a large number of aromatherapy sources as being oils that can be used undiluted. Undiluted use of lavender and tea tree, however, should be discouraged as severe sensitivity still could occur in some individuals. Again, the safest rule of thumb is to never use any essential oil undiluted.
Some oils can cause sensitization or allergic reactions in some individuals. When using a new oil topically for the first time, do a skin patch test on a small area of skin (it's easy). The How to Perform a Skin Patch Test page provides details.
Some essential oils are phototoxic and can cause irritation, inflammation, blistering, redness and/or burning when exposed to UVA rays. For more information, learn about phototoxicity and phototoxic essential oils.
Some essential oils should be avoided during pregnancy or by those with asthma, epilepsy, or with other health conditions. Be sure to research/review the safety precautions associated with each essential oil that you use.
Less IS More. When using essential oils, use the smallest amount of essential oil that will get the job done. If 1-2 drops are called for, for example, don't use more than that. Essential oils are highly concentrated. (As a sidenote, some companies or their representatives may suggest that you use as much as you want -- it's in their best interest that you go through your oils faster so you then need to reorder more frequently. Generally speaking, it takes a lot of plant material (i.e. flower petals, leaves, needles, bark, wood, root, etc.) to obtain the botanical's essential oil by steam distillation. It's wasteful to use more essential oil than is needed for your particular application.)
Not all essential oils are suitable for use in aromatherapy. Wormwood, pennyroyal, onion, camphor, horseradish, wintergreen, rue, bitter almond and sassafras are examples of some of the essential oils that should only be used by qualified aromatherapy practitioners, if ever at all.
Never let children use essential oils without the presence of an adult knowledgeable about their use. Most essential oils smell wonderful and many essential oils such as citrus oils can smell like they are "yummy" and safe to drink. ALWAYS keep your essential oils away from children. Treat the oils like medicines that are poison in unknowing hands.
Essential oils should not be taken internally without guidance by a qualified practitioner or until you have gained adequate knowledge and understanding of the risks and safe internal applications and dosages. Even though essential oils are cold pressed or steam distilled from a range of citrus and common spices like Lemons, Oranges, Grapefruits, Allspice, Basil, Black Pepper, Cinnamon, Clove, Fennel, Ginger, Rosemary and a number of other botanicals that are routinely ingested without the need for precautionary usage info, essential oils are highly concentrated and should not be ingested without thorough understanding of appropriate usage and risks for each oil.
Essential oils are flammable. Keep them out of the way of fire hazards.