Why Do Our Eyes Burn On Chopping Onions?

 

Chopping onions can be the most difficult task while cooking, because the unbearable burning and watering of eyes when onions are cut into slices. But why does it actually happen? Well, the answer lies in Chemistry.

When an onion is chopped, the onion cells present inside release acidic chemicals like amino acid sulfoxides, along with some sort of enzymes. These react with each other to form a compound named syn-Propenthial-S-Oxide.

This chemical is a volatile one and can easily turn into gas. When it comes in contact with our eyes, it reacts with the liquid that lubricates our eyes, causing burning sensation.

However, the burning subsides after some time as our lacrimal glands produce disinfecting tears in order to wash off the acid.