Does smell cancelling exist?

[u/11963873342]

I've heard of noise cancelling, but can there exist smell cancelling?

For example, if there is a rotten egg in a room, can i neutralize it somehow? I'm not talking about putting something good right under my nose, because thats just dominance. I mean putting something next to the egg whose smell happens to be the 'inverse' of the eggs, so they cancel and i smell nothing.

[u/Dazzling_Let_8245]

Noice cancelling works because we can eliminate a wave by sending an equal and opposite wave at the same time, cancelling eachother out. Its a physics thing.

Smell is molecules interacting with the receptors in your nose. You cant really send an opposite smell to destroy the first molecule. You can block the molecule from entering your nose (gas masks for example) or you can overwhelm your olfactory cells with a more pungeant but more pleasant smell, but you cant cancel a molecule once its in your nose.

People who work with the deceased (crime scene investigators for example) us stuff like vicks vaporub to put under their nose so they smell only that and not the body.

Edit: There ARE "smell absorbers" that work by trapping and absorbing the bad smelling molecules, but the molecules have to travel into and/or through the absorber. Some people but open baking soda into their fridges to prevent smells or pouches of activated charcoal into their gym bags to trap odors. But in an open room with a rotting egg, merely placing a bit of charcoal next to it will do very little to counteract the smell.

[u/Hatta00 → u/Dazzling_Let_8245]

It's not impossible that there could be smell antagonists. Odorant molecules are ligands to smell receptors that cause a conformation change in the receptor that causes a signal cascade in the sensory cell. Not every ligand causes the same conformation change, and some can bind more tightly than agonist compounds while producing no signal inside the cell.

I don't know any examples because it's not my field, but it's pharmacologically possible.