Eucalyptus oil as a home scent, and why a little is enough
Eucalyptus oil is a thin, almost colourless essential oil drawn by steam from the leaves and twigs of eucalyptus trees. It smells sharp, cool and camphor-like, and as a home scent a very small amount goes a long way.
By the editors of Aromatherapy Oil DiffuserUpdated 4 October 20265 min read
In short
- Eucalyptus oil is steam-distilled from the leaves; the Latin name on the back says which of several quite different kinds you have.
- It is one of the stronger oils on the shelf, so a diffuser needs fewer drops and shorter spells than with a citrus oil.
- It is never swallowed, stays away from young children and pets, and is a room scent rather than a treatment.
Which eucalyptus is in the bottle
There are hundreds of species of eucalyptus, native to Australia and now planted in warm countries around the world, and only a handful are distilled for their oil. The front of a label often says just eucalyptus. The Latin name on the back tells you which tree it came from, and they do not smell alike.
| Name on the label | Common name | How it smells |
|---|---|---|
| Eucalyptus globulus | Blue gum | The sharpest and most camphor-like; the smell most people expect |
| Eucalyptus radiata | Narrow-leaved peppermint | Softer and a little sweeter, less piercing |
| Eucalyptus citriodora or Corymbia citriodora | Lemon eucalyptus | Lemony, close to citronella, hardly camphor-like at all |
| Eucalyptus fragrance oil | A composed scent, no tree named | Built to smell of eucalyptus; the ingredient line usually lists parfum |
The sharp note in the first two comes from a compound called 1,8-cineole, which some labels list as eucalyptol. Lemon eucalyptus holds very little of it, which is why it smells like a different plant altogether. A bottle with no Latin name is best treated as a fragrance oil.
How it smells in a room
Eucalyptus is cool, green and a touch medicinal, the smell of a leaf crushed between finger and thumb. It is a top note, so it reaches the nose quickly and fades sooner than a wood or a resin. Many people find it clean and bracing; sniff the cap before you commit a whole tank to it.
It suits the rooms where fresh matters more than cosy: a bathroom, a hallway, a kitchen after frying. In a blend it sharpens lemon or peppermint, takes the sweetness off lavender and turns more herbal next to rosemary. In a sitting room of an evening, most people prefer it as the smaller part of a blend. If the device is still undecided, our side-by-side of water-tank and waterless machines shows which kind takes a loose essential oil.
Using it sparingly in a diffuser
The usual mistake is to dose eucalyptus the way you would dose orange. These steps keep it on the pleasant side.
- Read the leaflet for your machine. A water diffuser takes drops in the tank; a pod machine takes only its maker's pods, and loose oil has no place in it.
- Begin below the leaflet's upper figure for drops, and lower still when eucalyptus is one oil in a blend.
- Run a short spell with the door ajar, then switch off. The scent stays in the room after the mist has stopped.
- Step out and come back in before adding anything. A nose stops reporting a constant smell long before the smell has gone.
- Tip out the water and wipe the tank when you finish, or the next fill will carry eucalyptus too.
Room size counts as much as the number of drops. A machine made for a large living room will overdo a box room on any setting, and our overview of the reach each kind of diffuser states lists the square metres makers give, where they give any.
Children, pets and other cautions
Eucalyptus is one of the oils where care is most often advised around the youngest in the house. The common advice is not to diffuse it where a baby or young child sleeps or plays, and never to put it on or near a child's face. If there is a baby or small child at home, or you are pregnant or have asthma or allergies, a doctor is the one to ask before you use it.
Animals come next. Cats, dogs and birds are commonly said to cope badly with eucalyptus, so do not run it in a room an animal cannot leave, and keep both bottle and diffuser where nothing can lick them or knock them over. Ask your vet before diffusing around any pet.
Keeping the bottle in good order
Leave the oil in its dark glass bottle, upright, with the cap screwed down, in a cool cupboard away from the hob, the radiator and the windowsill. Air and daylight age it, and an oil that has turned flat, harsh or sticky goes in the bin. Wipe up drips at once, because neat oil can mark varnish and some plastics. It is flammable too, so keep it away from candles and gas flames.
Used this lightly, the smallest bottle on the shelf is the sensible buy. What a scent costs to keep going depends far more on the machine than on the oil, and our rundown of refill costs for each type of diffuser sets those figures out.
Eucalyptus chosen, machine still to pick?
Our guide sets out which diffuser takes which oil, the reach makers state for each type and what it costs to keep running.