The following lists factors that influence the safety of an essential oil:
- The quality of the essential oil – only use pure, unadulterated essential oils (not fragrance oils – which are typically what you will find for sale at Walmart, TJ Maxx etc.) from reputable companies. If a company is selling an essential oil at a significantly reduced price, or selling various types of essential oils all at the same price, it is a red flag and may indicate that the essential oils are either adulterated or not true essential oils.
- Chemistry of the essential oil – Essential oils that are rich in certain constituents (for example aldehydes or phenols – which can cause skin irritation) require extra caution. Such essential oils may require that they are diluted to much lower concentrations than in ordinary circumstances, in order to prevent irritation of the skin.
- Method of application – Essential oils can be applied topically (on the skin), inhaled, diffused or taken internally (only if you are following the advice of a professional properly trained in internal use of essential oils). Each of the application methods will have different safety concerns that need to be taken into consideration.
- Age of the client – The age group most prone to adverse reactions or toxicity are infants, toddlers and young children. With young children certain essential oils should be avoided altogether (see the section below on Babies, Children & Essential Oils for more detailed information) or used under the guidance of a knowledgeable professional, at a highly diluted percentage. The elderly are also at a greater risk for skin irritation/sensitivities, so a lower concentration may be warranted for topical blends.
- Condition of the skin – Skin that is damaged, diseased or inflamed is more susceptible to dermal reactions & sensitization. Essential oils should never be applied undiluted to an area where the integrity of the skin is compromised, as the skin condition could be worsened causing larger amounts of oil than normal to be absorbed.
- Dosage/Dilution to be applied – When neat (undiluted) or higher percentage dilutions are used, it is more likely to cause an adverse reaction to the essential oil, like skin irritation or sensitization.