Essential oils, the safe and simple way.

Essential oils for beginners: how to use them safely at home

What an essential oil is

An essential oil is the concentrated scent of a plant, pressed from citrus peel or distilled from leaves, flowers, wood or resin. One small bottle holds the aroma of a lot of plant material. That is why a few drops go a long way, and why the same few drops can irritate skin when they come straight from the bottle.

People have used aromatic plants for centuries in baths, balms and cleaning. Today the main uses at home are simple: a pleasant smell in a room, a scented body oil or bath, and a fresh note in homemade cleaners. Essential oils do not treat, cure or prevent illness, and a good guide never says they do.

How to dilute essential oils

Mix essential oils into a carrier oil, such as jojoba, sweet almond or fractionated coconut, before they touch your skin. A standard dropper gives roughly 20 drops per ml, so a 10 ml roller holds about 200 drops of carrier. Two drops of essential oil in it gives about 1%.

Start at the low end. Patch test a little of the diluted blend on the inner arm and check it over the next day. If the skin turns red, itchy or warm, stop and wash it off with soap and water.

Diffusing safely

Most ultrasonic diffusers need 3 to 5 drops per 100 ml of water. Run them for 30 to 60 minutes, then give the room a break and some fresh air. A diffuser running all day keeps the air loaded with scent, which can bother people with sensitive airways and pets that cannot leave the room.

• Small room or bathroom: about 3 drops per 100 ml.
• Bedroom or office: about 4 drops per 100 ml.
• Open living space: about 5 drops per 100 ml.
• Clean the tank every few uses, as the maker says.

Kids, pregnancy and pets

Children have thinner skin and smaller airways. Peppermint and eucalyptus stay away from the faces of babies and young children, and no oils go near a baby under three months. If you are pregnant or breastfeeding, take medicines or have a health condition, ask your doctor or pharmacist before using essential oils.

Cats are especially sensitive to some compounds in essential oils, and dogs have far stronger noses than we do. Never put oils on a pet, keep diffuser sessions short and leave a door open so the animal can walk away. Ask your vet before diffusing around a pet with health problems.

Reading the label

"Therapeutic grade", "pure" and "premium" are marketing words, not official standards. A useful label tells you the plant's Latin name (Lavandula angustifolia, not just "lavender"), the part of the plant, the country of origin, how it was made (steam-distilled or cold-pressed) and a batch number. Amber or blue glass with a dropper cap is a good sign; clear glass and plastic are not.

Storage and shelf life

Heat, light and air make oils oxidise. Oxidised oils smell sharper and are more likely to irritate skin. Store bottles in a cool, dark cupboard with the cap tight, and write the opening date on the label.

When an oil passes its date or smells sharper, it can still freshen a cleaning spray. It just should not go on skin.

Your first four oils

You do not need a 30-bottle kit. Four oils cover most home uses and get used up while they are fresh:

• Lavender (Lavandula angustifolia): soft and floral, the classic evening oil.
• Sweet orange (Citrus sinensis): bright and cheap, lovely in the morning diffuser.
• Cedarwood (Cedrus atlantica): dry and woody, it anchors any blend.
• Tea tree (Melaleuca alternifolia): clean-smelling, a classic for cleaning sprays.

Try the scent family finder above to see which four fit your nose, then the dilution calculator for exact drops.