Air fresheners are everywhere. In public toilets, at work, in your house and sometimes hanging from the mirror in your car, but how do they work?
Do they really eliminate odours? Can they hurt us? How are they different from perfume?
Here’s everything you need to know about air fresheners…
How do Air Fresheners Work?
Air fresheners use “volatile substances”, which simply means that the molecules easily change form from liquid to gas (even at room temperature). Our sense of smell is tuned in to detect gas molecules drifting around the air, more so than it is to detect liquids.
Spray air fresheners, which are still the most popular freshener type, are aerosols. The word aerosol means “dissolves in air”, so the liquid that shoots out of an air freshener under pressure quickly evaporates when released into the standard pressure of open air.
The aerosol propellant is mixed with fragrance molecules before being released into the air, where it covers up the bad odours. Most of the time, they simply replace a bad smell with a stronger, nicer smell. Certain air fresheners also aim to reduce your sensitivity towards smells; so, instead of masking once scent with another, they anesthetise your nose to reduce your sensitivity to bad scents (reducing their unpleasant impact).
How do Odour Eliminators Work?
Most air fresheners don’t actually kill a bad smell. Rather than remove the smell from the room, masking fresheners simply cover a bad smell with another scent, which appears more pleasant to our senses. So, what about the air fresheners that claim to eliminate bad smells? How do they do it?
The key to odour eliminating air fresheners is a molecule called cyclodextrin. This is a donut shaped molecule suspended in a water carrier. Due to cyclodextrin’s hydrophobic interior, it attracts the odour molecules in the air. As the water dries, the molecules on the interior of the cyclodextrin are encapsulated inside, therefore reducing their volatility and minimising their smell.
Are Air Fresheners Harmful?
Whilst there are articles around that would argue otherwise, when used in moderation and safely, air fresheners are not dangerous.
When used sparingly and sensibly, standard air fresheners aren’t likely to cause any trouble. However, it’s important to remember that they’re not advised for people with serious lung conditions or allergies towards the air freshener’s contents.
How are Air Fresheners Different from Perfumes?
Aside from costing a lot more, perfumes are quite different from your standard aerosol air fresheners. Perfumes use compounds that are “unstable”, meaning the water molecules break away from each other, diffusing in the air. This process is sped up by heat and a surface area exposed to air, which is why perfumes are ideally placed on open areas on the skin, such as the neck.
Air fresheners, on the other hand, either drift around in the air to mask a bad smell or bind with other volatile smells to neutralise them.