How to dilute essential oils: a simple safety guide

Essential oils are the most concentrated things on our shelves. A single drop of lavender holds the work of a great many flower heads, and that potency is exactly why these oils should never go on skin neat. Dilution is not a compromise, it is simply how essential oils are meant to be used. After two decades behind the counter at Herbaty Organics, the question our founder Dr. Hamza Nassrallah hears most often is the simplest one: how much is enough? Here is our practical answer.

The simple dilution rule

Work in drops per tablespoon. One tablespoon, about 15 ml, of carrier oil is your base. Roughly 20 drops make up a millilitre, which gives you three numbers worth remembering:

• 1 percent, 3 drops per tablespoon. For the face, for sensitive or mature skin, and for anything you plan to use daily.
• 2 percent, 6 drops per tablespoon. The everyday choice for a body blend, and the one most people want.
• 3 percent, 9 drops per tablespoon. A sensible ceiling for most adults, on a small area, for a short stretch of time.

Blend straight into a bottle, cap it, and roll it gently between your palms. When in doubt, use less. A lighter blend smells just as lovely and sits far more kindly on the skin.

Choosing your carrier

The carrier does the real work here, spreading a few drops safely across a larger area, so pick one you actually enjoy wearing. Sweet almond oil is the classic all-rounder: mild, faintly nutty, and slow enough on the skin to be pleasant for a massage blend. Jojoba oil is technically a liquid wax, which is why it feels light, absorbs quickly and keeps its character for a long while in the cupboard. Fractionated coconut oil, sold as MCT oil, is clear, odourless and stays liquid, so it will not compete with the scent of your blend. Any of our carrier and infused oils will do the job; the differences are texture, aroma and how quickly they sink in.

Patch test, every time

Mix your dilution first, then dab a little on the inner forearm and leave it be for 24 hours. If the skin stays calm and comfortable, carry on. If there is any redness, itching or stinging, wipe the area with plain carrier oil, wash gently with a mild soap, and set that particular oil aside. Repeat the patch test whenever you try a new oil or open a new bottle. Skin can be particular, and it is allowed to be.

Oils that ask for extra care

Some oils are naturally hot on the skin and deserve a lighter hand. Cinnamon bark is the strictest of all, and the simplest answer is to keep it out of skin blends entirely and enjoy it in a diffuser. Keep clove bud, oregano, thyme and lemongrass to 0.5 percent at the very most, and treat the diffuser as the easier home for all of them. Peppermint is stronger than its friendly scent suggests, and it is not suitable for young children at all. Cold-pressed citrus oils are a separate matter: bergamot especially, along with lemon and lime, can leave skin far more sensitive to sunlight, so keep them off any skin that will see the sun within 12 to 24 hours.

Handling, household and storage

We will always be plain about this: essential oils are for external and aromatic use only. Never swallow them, never add them to food or drink, and never apply them inside the mouth or nose. Keep every bottle tightly capped and well out of reach of children, since the lovely smells are exactly what makes them tempting. Pets deserve the same caution. Cats in particular do not process these compounds well, so diffuse only in a ventilated room with the door left open, and never apply oils directly to an animal.

Light, heat and air slowly change an essential oil, and an oil that has oxidised is more likely to irritate skin. Keep your bottles in dark glass, tightly capped, in a cool cupboard away from sunlight, never on a warm windowsill or a steamy bathroom shelf. Write the date you opened each bottle on the label: citrus and pine oils are happiest used within a year of opening, while most others keep well for two or three. Blends made with a carrier follow the shorter clock of the two, so make them in small amounts and use them while they still smell fresh.

Since 2005 our advice has not changed: measure, dilute, patch test, store well. If you would like to browse before you blend, our essential oil collection lists what each oil smells like and where it comes from, and if you are ever unsure about a particular oil, write to us. We would much rather answer a small question than hear about a sore forearm.