Fart Facts: Fart Myths

Landen's uncle Ryan sent over this great info on fart myths from a fairly recent episode (Episode #48) of Discovery Channel's Mythbusters.  This info is a reprint from the Unofficial Mythbusters Blog:

(If you're visiting today from the Digg post you can see a better version of the fart lighting episode here)

These are the 3 myths they tried to bust:

• You can die from the fumes of your own flatluence: busted
• Beans and bubbly drinks increase your flatulence: confirmed
• Matches burns up the smell of farts: busted

Flatulence Myths

Deadly farts

Myth: A bean-loving man, living in a small  poorly ventilated room, suffocated from his own farts.

Adam built a bathtub-based flatus (fart) catcher that trapped the exhaust in a small Flatulence Containment Unit (FCU). Rob Werden of replicaprops.com acquired an FCU from this episode (seen here, held by Adam):

credit Rob Werden, used with permission

He also got a resin casting of Adam's head (for ballistics gel molds) and a crew cap, which you can checkout on the Mythbusters fan club message board. There are also some pretty cool replica props on his site, especially if you're a Smallville fan.

Amusingly enough, Grant issued a call on the MythBusters fan club message board for volunteers to provide "flatulence samples." Those volunteers were spared camera footage of them inside the fart catcher, but viewers were treated to the sight of a pale Adam in speedo catching his bubbles.

Finding the components of flatus

The water was too cold and Adam was unable to deliver the goods at first. "I wasted a really good one at six o' clock this morning." After a good wait, Adam bubbled up a good 13.5mL flatus and followed with several more. Adam and Jamie sent Kari with four of Adam's flatus samples to have tested at UCSF. They found that Adam's samples were mostly air -- nitrogen, oxygen, and a little bit of argon -- but there was also some methane, carbon dioxide (CO₂), the smelly bits: hydrogen sulfide and methyl mercaptan.

Reaching deadly concentrations with flatus

They started with testing the carbon dioxide component, as it can be deadly in high concentrations and it was also present in larger quantities

Affects of CO₂ concentrations on human health:

• 2% cerebral dilation, increased blood pressure, nausea, confusion
• 8% nausea and vomiting
• 10% death within minutes

Largest flatulence rate they recorded in their study was 170mL/hour. Based on this rate, they pumped in eight hour's worth of flatus CO₂ into a small chamber with Buster. The CO₂ concentration reached 0.06%. At that rate, it would take 100 days to reach a lethal levels. Breathing causes more CO₂ buildup, so they put Jamie in the chamber next and measured the change in the CO₂ concentration. The levels reached 0.14% in 20 minutes and 1.28% in 4 hours. At that rate it would take 36 hours to reach deadly levels. Faster, but still unlikely.

They calculated how long it would take to reach deadly concentrations from other components of flatus:

• Methane (deadly at 2%): 441 days
• Hydrogen sulfide: 22 years

busted

Do some foods lead to more flatulence?

Myth: Some foods (e.g. beans, bubbly drinks, meat) can lead to more flatulence

The gas contained in flatus can come from several sources: butt burp (i.e. swallowed air makes its way all the way through your system), gas byproducts from food.

For three days, the MythBusters kept diaries of their farting to get a good baseline for their farting:

• Kari: 3 times
• Jamie: 6
• Adam: 10

For the test the effect of various foods, Adam is given beans, Kari is given bubbly drinks ("oh, I hope my dentist isn't watching"), and Jamie is given meat.

After 24 hours on their new diet:

• Kari: 5 farts
• Jamie: 6 farts
• Adam: 22+ farts

meat: busted

bubbly drinks, beans: confirmed

Does lighting a match dissipate the smell?

Myth: a lit match can eliminate the smell of a fart

Adam made a small, sealed chamber and they pumped it full of the smelly gases in flatus. They measured the concentration of a the gases before and after remotely setting off a match. They first pumped in hydrogen sulfide and found no change in the levels of concentration after they lit the match. They then tried the same test with methyl mercaptan and found the exact same result. Based on this test, they could already bust the fact that lighting a match consumes the smelly gases in any way, but they still wanted to see if a match masked the smell of the gases.

Lucky researcher John Hunt was brought in to be the official nose to given his own ten-point scale judgement of the smelliness of the box before and after the lighting of the match:

• Hydrogen sulfide: 5.5 pre-match, about the same post-match
• Methyl mercaptan: 4 pre-match, 2 post-match

busted

Wikipedia breaks it all down in nice and simple fart chart