I did not know that yesterday!

This isn't the most pleasant topic, but questions relating to the bowels are usually worth answering. After all, if we can help prevent just one unnecessary odor, then we've done noses the world wide a great service.

The MadSci Network offers several theories about why matches neutralize odors. The site also notes that smell is subjective, meaning it's possible the "match effect" is in our heads. However, if you're willing to play along and assume a match really does work, there are a few possible reasons why.

When a match is struck, it produces sulfur dioxide, a "very pungent substance, to which the smell receptors are extremely sensitive." MadSci explains, "You can smell a minute amount of sulfur dioxide, but when you have done so, you will not smell anything else for a while." So, the match doesn't really get rid of the odor -- it just covers it up. This seems the most likely explanation, but MadSci presents a few other possibilities, including "oxidation of smelly substances in the flame" and "absorption of smelly substances onto the smoke."

The TV show "MythBusters" covered this topic and concluded that matches mask the methyl mercaptan found in flatulence and feces. So, a match may not eliminate odors, but it will push them to the background. Most of the time, that's good enough.

Source: ask.yahoo.com