Essential oils for internal use: Are they safe?
By Marco Valussi
No. But wait... this question really hides two of them. The first question is whether the risks involved in taking an essential oil by mouth are the same as when applying it on the skin. The second question is whether labeling an essential oil as food grade means that it is safer, of greater quality or more effective than an oil labeled as a cosmetic or as an aroma for environments.
- Let's answer the first question.
The oral (mouth) intake exposes us to very different risks than those involved in a topical (skin or mucosa) use. Absorption is much greater for mouth (up to 100%) than transcutaneous absorption (on average 4-5%), and the concentration and quantities that can be used for mouth are much higher. For this reason, the amount of essential oil that can enter the blood stream is greater and, therefore, both the possible therapeutic effects and the adverse effects could be more important. While gastrointestinal mucous membranes are made to help absorb nutrients, the skin has a much stronger protective and insulation function from the outside, and therefore protects us better from the absorption of potentially dangerous molecules.
So it is true that we can use on the skin oils that we would not us (or would use with more caution) by mouth, for example Tea Tree oil, Eucalyptus oil, Citronella oil, etc.
- As for the second question, the answer is no again
Let's take for granted that we're talking about real essential oils, not adulterated with synthetic substances, solvents, etc. If we are talking about real essential oils, then we know by definition that they may have been produced only by means of water steam distillation or cold pressing, two methods of obtaining that are intrinsically food-grade in the sense that they do not use solvents, only use mechanical and physical means to obtain the essential oil, and should only enter into contact with stainless steel and glass. The fact that an essential oil is or is not authorized for oral use, such as a food flavour, depends on the nature of the essential oil itself, not on the method used to obtain it, which is still the same. The calamus essential oil (Acorus calamus) is not allowed in oral intake, or suffers from severe limitations, for the risk of ingesting carcinogenic substances. The same goes for Wintergreen oil (Gaultheria procumbens): whether it is labeled as food flavour or a cosmetic, a spoon is enough to kill an adult. And this also leads us to considering the fact that the purity and quality of an essential oil are not relevant to toxicity issues. For example, when someone on the web states that non food-grade essential oils may contain adulterates, solvents, and so on, declares the false, since it is not the food label that ensures that essential oil does not contain them, but the same definition of essential oil.
The choice, at least in Europe, to go on the market with a label such as "food flavour", or "food supplement", "cosmetics" or "home-made products" depends merely on marketing and commercial choices, and also on resolutions on litigation. The fact that a company's lavender essential oil has a label that says "not for internal use" has nothing to do with the quality of the essential oil itself, which will be measured in other ways. Rather, it is likely that the firm would rather sport a more restrictive label to have no responsibility if a customer decides to ingest the contents of the flask in one go. Or because in some cases the label protects the consumer more, discouraging it from internal use. The most important thing to remember when looking at a label is the choice of terms used, which is revealing. A label that uses terms such as "essence" or "perfume" is suspect.