Question

If we soak onion in water the irritation is reduced. Why?

Answer 1

It is due to the presence of a chemical, propanediol s-oxide in the onion. This is easily volatile. When we cut onion, some of the cells are damaged and the chemical comes out. It becomes vapor and reaches our eyes resulting in irritation and tears in eyes. If we soak onion in water, the chemical is diluted and it cannot reach our eyes. So the irritation is reduced.