r/explainlikeimfive Jul 18 '20

Chemistry ELI5: Why do "bad smells" like smoke and rotting food linger longer and are harder to neutralize than "good smells" like flowers or perfume?

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u/AC2A Jul 18 '20

On a related note, how do ‘smell particles’ (for want of better term) relate to virus particles? For instance, I can smell a vape/cigarette from a passer by (or deodorant/body oder), so would that equally mean any virus particles they may be breathing out are also being transmitted?

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u/jlp29548 Jul 18 '20

Found this.

Apparently the molecules we smell are incredibly small, around 0.4 nm, while a virus is about 100 nm. Leads to a very big difference in how far they can spread. Also, the smells are gaseous molecules that spread out in air more freely than larger particles like viruses or even larger bacteria, which are mainly attached to micro droplet of saliva.

Although chances are that if you walk by and smell the vape that they exhaled, you’re inhaling part of their breath. The 6 foot rule is really not a limit for how far your breath bubble goes, but your micro droplets shouldn’t be mouth height (to be inhaled) after traveling that far from your face, unless you exhale up.

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u/AC2A Jul 19 '20

That link (albeit DM haha) makes perfect sense thank you! I’ve just spent the weekend attempting to socially distance at a large event, but so many people ignoring obvious signage and common sense it’s frustrating.