---
title: Why onions make you cry
date: "2002-10-19T12:00:00Z"
categories:
  - links
wp_id: 1084
description: I explore the chemical reaction triggered by cutting onions, where specific enzymes release a gas that turns into a mild acid upon contact with moisture, causing the eyes to sting and produce tears.
keywords: [onions, chemistry, syn-propanethial-s-oxide, lachrymatory factor, sulfur, biology]
---

[Why onions make you cry](http://www.msnbc.com/news/822066.asp?cp1=1). [via Potti](http://potti.blogspot.com/)