WHY DO WE CRY WHEN WE CHOP ONIONS?

When we cut onion it releases a gas called propanethiol S-oxide. When mixed with certain enzymes in the onion, creates a sulfur gas. These gases then get to your eyes  & create a mild acid that irritates the eyes.

                         Propanethiol S-oxide
                                         +
                                   enzymes
                                         =
                                 sulfur gas