Air freshener, the seven kinds and what each one actually does
An air freshener is anything made to change the smell of a room by putting a fragrance into the air. It comes as a spray, a gel or block, a plug-in, a timed spray, reed sticks, a candle or an electric diffuser, and none of them removes the cause of a smell.
By the editors of Essential Oils DiffuserUpdated 29 October 20265 min read
In short
- Every kind adds a fragrance; none removes a bin, damp or a wet coat. Ventilate and clean first, scent second.
- A spray works for a moment, a gel, plug-in or reed bottle gives a faint background, a candle or an electric diffuser scents the hours you choose.
- Fragrance or parfum on the label means a composed scent; essential oil means the oil of one named plant.
What an air freshener does, and what it cannot
Every air freshener releases fragrance into the air, and your nose picks up the fragrance rather than the odour underneath. The thing that smells is still in the room, and once the fragrance thins out the bin, the damp corner or the wet dog is back.
So the order of work matters: open a window, wash the bin, dry out the damp, and then ask whether you still want a scent. Used that way an air freshener is a finishing touch; the other way round it hides a problem.
The seven kinds, side by side
| Kind | How it works | How long it lasts |
|---|---|---|
| Aerosol or pump spray | A burst of fragrance in fine droplets, strongest at once | The shortest; it fades as the droplets settle |
| Gel or solid block | Fragrance evaporates from a block as it shrinks | Until the block has dried down |
| Plug-in | A low heater in a socket warms a wick in a bottle of scented liquid | As long as the refill lasts on the setting you choose |
| Automatic timed spray | A battery unit releases a metered puff at a set interval | Until the can is empty |
| Reed sticks | Scented liquid climbs the reeds and evaporates from the tips | Until the bottle is empty, faint and constant |
| Candle | Fragrance lifts from the warm wax around the flame | Only while it is lit |
| Electric diffuser | A machine puts out oil as a fine mist at a setting you pick | For the hours you set |
Each kind in a few lines
- Spray: for a moment, the loo after use or the hall before a visitor rings. The droplets settle, so keep it off polished wood and food.
- Gel or block: quiet and cheap; it is noticed most in a small shut space.
- Plug-in: an upright socket, nothing draped over it, and a lower setting than you think.
- Timed spray: a wall box with a can inside; the longest interval the room gets away with.
- Reed sticks: the softest background of all. Turn the reeds now and then so the wet ends face the room.
- Candle: scent with light and warmth, and the care any flame needs.
- Electric diffuser: the only machine here. Most take a few drops of oil in water and make a cool mist; some take sealed pods of blended oil and give a dry mist.
What the diffuser adds is control: a dial for strength, a timer for the hours and a refill you choose; what you pay for is the machine up front. Our comparison of electric diffusers for UK homes puts seven side by side on stated room size, run time per fill and refill cost.
Where each kind belongs in a home
- Hallway: faint and constant, a reed bottle or a gel.
- Loo: a spray for the moment or a timed spray on the wall; the window or extractor does the real job.
- Kitchen: extractor and window first, a candle or a spray after cooking. Never a plug-in next to the hob.
- Living room: a candle or an electric diffuser for the evening, off when you leave.
- Bedroom: the least of all. A diffuser on its lowest setting with a timer, a faint reed bottle, or nothing.
- Cupboard and wardrobe: a block or a sachet, never a flame or a plug, and air the space out first.
A room with a socket and a surface at hip height is where a diffuser earns its place. The seven diffusers we set side by side on stated room size shows which suit a large open-plan room and which a bedroom.
Fragrance or essential oil on the label
The front of a pack says what it smells of; the back says what it is. Fragrance or parfum on the ingredient line means a composed scent, blended from aroma compounds that may be synthetic, natural or both. It is the norm in sprays, gels and plug-ins, and why those can smell of fresh linen or sea air.
Essential oil means the oil distilled or pressed from one named plant, usually with its Latin name beside it. A pack that says with essential oils can still be mostly fragrance, and many packs print no full ingredient list at all. Neither word is a safety mark, and both belong away from children, pets and bare skin.
If the label decides it for you, a diffuser keeps the choice in your hands: a water diffuser takes the essential oil you buy, a pod machine the maker's blended oil. Which diffuser takes loose oil and which takes pods is set out in our comparison, with what a millilitre or a pod costs.
Weighing an electric diffuser?
Seven electric diffusers side by side on stated room size, run time per fill, noise and what a millilitre of oil or a pod costs.