Essential oil safety: dilution, photosensitivity and what the label allows

Most of what is written about essential oil safety online was written for the American market. The bottle you buy in Germany, Austria, Switzerland, the United Kingdom or Ireland is labelled under European rules, and on some oils the two say different things. This page collects the parts that actually apply here.

Dilution: the one number worth memorising

Essential oils are concentrated plant extracts. Undiluted on skin they can cause irritation and, over time, sensitisation — a reaction that does not go away once it has developed. Dilute in a carrier oil before applying to skin. Fractionated coconut oil, jojoba, sweet almond and plain olive oil all work.

The arithmetic is easier in drops than in percentages, because a bottle of carrier oil is usually 10 ml or 30 ml:

Strength Drops per 10 ml carrier Typical use
0.5 % 1–2 drops Face; anyone over 65; anyone with sensitive skin
1 % 3 drops Children over six; daily body use
2 % 6 drops Adults, general body use
3–5 % 9–15 drops A small area, for a short period

More is not better. Above roughly 5 % the risk rises and the benefit does not.

Never on skin undiluted, and never in eyes, ears or on mucous membranes. If oil does get in an eye, wipe with a carrier oil — not water, which spreads it.

Photosensitivity: citrus oils and sunlight

Several cold-pressed citrus oils contain furocoumarins, which react with ultraviolet light. Skin that has had them applied and is then exposed to sun or a sunbed can burn or discolour, sometimes days later, and the marks can last months.

The oils usually flagged are the expressed citrus peels — bergamot above all, then lemon, lime, grapefruit, bitter orange. Steam-distilled versions of the same fruits generally are not photosensitising, and neither is expressed sweet orange in normal use. Because the distinction is between one bottle and another rather than between one fruit and another, the bottle is the authority: every product page on this site records whether that specific oil is flagged for photosensitivity in Europe.

The usual guidance is to keep treated skin out of direct sun and away from sunbeds for twelve hours after applying. Diffusing is not affected.

Food use: the label on the bottle decides

This is the difference that catches people out. In the United States a wide part of the doTERRA range is sold with supplement labelling and used in food. In the European Union and the United Kingdom, an oil may only be used in food when it is sold and labelled as a flavouring, and only in the amounts that label states.

Two oils make the point: Bergamot and Wild Orange are routinely used in American recipes but are not labelled the same way here. An American recipe that drops them into a cake is not transferable.

The safe rule: if the bottle in your hand does not say it is for food, it is not for food — regardless of what a blog written in Utah says. Every oil in the directory carries its European food-use status.

Children, pregnancy and pets

Storage, shelf life and the bottle itself

Heat, light and air are what degrade essential oils. Keep them capped, upright, in the dark, away from the cooker and the bathroom window. Citrus oils oxidise fastest — roughly a year or two once opened — and oxidised citrus is more irritating to skin than fresh, which is a practical reason not to keep a half-used bottle for five years.

The batch number printed on the label is what doTERRA’s published test results are indexed against.

What this site will never tell you

That an essential oil diagnoses, prevents, treats or cures anything. It does not, and claiming otherwise is both untrue and — in Europe — not permitted. Oils are pleasant, useful household and cosmetic ingredients. If something needs a doctor, it needs a doctor.

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