Question: How does Febreze actually kill dirty smells? Their latest advert bugs me because I'm not sure how it works.

Stuart Archer answered on 19 Jun 2013:

Your body registers smells when the smelly molecule binds to a smell receptor inside your nose. Febreeze contains a molecule called ‘beta-cyclodextrin’, which is a donut-shaped made up of 8 sugar molecules joined together, dissolved in water (with a few other things to make it smell nice).

What happens when you spray it onto something is that the ‘smelly’ molecule will dissolve a little bit in the water and then get stuck in the hole in the middle of the cyclodextrin ‘donut’. Because the smell is now trapped in the hole, it can’t bind to the smell receptor in your nose. You can then wash the item in question, which washed out the cyclodextrin with the smell molecule trapped inside, removing it completely.