Why does lighting a match cover the smell of poop?

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Offline AndroidNeox

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Why is lighting a match so effective at covering the aroma left when one has performed a bowel movement? Is it just covering the odor or is there a chemical reaction actually eliminating some aromatic chemicals?

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Offline Pmb

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Re: Why does lighting a match cover the smell of poop?
« Reply #1 on: 28/01/2013 12:47:49 »
Why is lighting a match so effective at covering the aroma left when one has performed a bowel movement? Is it just covering the odor or is there a chemical reaction actually eliminating some aromatic chemicals?
Mythbusters did an experiment on this once. I believe that they determined that the flame burned up one of the components of the gas passed during flatulence while the sulfur covered the smell. One notable thing I recall was that a bic lighter didn't work, only a match worked.

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Offline Bored chemist

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Re: Why does lighting a match cover the smell of poop?
« Reply #2 on: 28/01/2013 22:13:46 »
One possible explanation is that sulphur dioxide (from the match) will react with hydrogen sulphide which is one component of the odour of flatus.
2  H2S + SO2 --> 3S +2H2O

The elemental sulphur (the 3S) doesn't smell.

However that reaction is quite slow: I wonder if a big part of the effect is simply covering up.

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Offline AndroidNeox

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Re: Why does lighting a match cover the smell of poop?
« Reply #3 on: 01/02/2013 22:22:45 »
I don't believe the match flame burns up the odiferous gases because only a tiny fraction of the air in the room is exposed to the flame.

Bored, your explanation seems more likely to me.