Why Do Onions Make You Cry?

Unless you’ve avoided cooking, you probably cut up an onion and experienced the burning and tearing you get from the vapors. When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.

I know most of you guys know this, but I wanted to share this article anyways…if you want to know more go to this website

Rodrigo Monsalve


chemistry 1045 said...


It is really interesting to see that chemistry is involved in everything we do!
It could also give us the reasons why we cry from cutting an onion!!!

wow!!.. thanks for posting this interesting article!!!

chemistry 1045 said...

Ups!!! posted by NOHORA =P