How Fart Lighting Works

Why You Can Light a Fart on Fire

Fart on Fire
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Did you know you can light farts on fire and that the color of the flame will depend on your personal biochemistry? Here's a look at how fart lighting works, the chemicals responsible, and how to light farts safely.

Why Are Farts Flammable?

Farts (the informal name for flatus or flatulence) result from normal bacteria in the digestive tract breaking down food into simpler chemical compounds. Everyone hosts their own personal colony of bacteria, so the gas signature you produce is your own unique flammable aroma. The color of the flame depends on personal biochemistry.

Gases in Farts

Although the exact chemical composition of farts varies from one person to the next, there are six common gases:

Hydrogen, hydrogen sulfide, and methane are flammable gases that will produce a flame when exposed to an ignition source, such as a match or lighter. With the energy from the ignition, the flammable gases react with oxygen from air and flatus to produce oxides and water. The smell of farts results from hydrogen sulfide as well as indole, skatole, short-chain fatty acids, and volatile amines.

Colored Fart Flames

Hydrogen is the most abundant gas in most farts, so most flatus burns with a yellow to orange flame. However, if you are a member of the population that produces flatulence high in methane, you may yield a blue flame. This is relatively uncommon, so producing the 'blue angel' or 'blue dart' is considered a sort of special talent in certain circles. In order for the flame to be blue, the concentration of methane needs to be high. Eating foods high in sulfur (e.g., broccoli, cabbage, kale) may enrich methane content in flatulence. However, this only matters if you already host the right bacteria.

The gases depend more on the species of bacteria than on the foods you eat, although diet certainly impacts the quantity of flatus that is produced and stored in the rectum. The only way to change the color of your farts, as far as I know, is to switch out the bacteria in your gut for a new set. To some extent, this occurs naturally over time. Illness or exposure to certain antibiotics can wipe out the bacteria, allowing others to colonize.

How To Light a Fart on Fire (Safely)

Okay, so lighting gas on fire is not an inherently safe project since the flammable gas is released from inside your body, but if you are curious about the color of flame your fart produces or just feel like igniting flatus because it's funny, there are some tips that will help protect you and the person lighting the fart:

  1. Wear clothing. Not only does this protect onlookers from seeing body parts they may not wish to view, but it protects delicate skin from burns. Assuming you fart forcefully, plenty of gas will make it through the barrier to produce a display. Natural fibers (e.g., cotton, silk, wool) are less likely to catch fire or melt than synthetic fibers (e.g., nylon, polyester).
  2. If possible, light the fart with a long-handled match or lighter. This reduces the chance of burning one's hand.
  3. Not that they would, but don't let people get up close and personal viewing the project. Protect eyes and faces (and noses).
  4. Just in case something goes wrong, be prepared to put out a fire. Smother a fire by dropping and rolling or covering the affected area/object with a nonflammable material. Water works to extinguish fart fires.
  5. It's really not advisable to light farts when intoxicated. This applies to all fire projects. You're less likely to be thinking clearly and your ability to react to an emergency may be impaired. Your friends will upload embarrassing videos and text pictures to everyone on the planet. You know the drill.

People do get burned lighting farts, so by no means is this practice encouraged.


  • Ohge, H; Furne, JK; Springfield, J; Sueda, T; Madoff, RD; Levitt, MD (November 7, 2003). "The effect of antibiotics and bismuth on fecal hydrogen sulfide and sulfate-reducing bacteria in the rat". FEMS Microbiology Letters. 228 (1): 137–4 2. doi:10.1016/s0378-1097(03)00748-1
  • Suarez, F; Furne, J; Springfield, J; Levitt, M (May 1997). "Insights into human colonic physiology obtained from the study of flatus composition". American Journal of Physiology. 272 (5 Pt 1): G1028–33. PMID 9176210
  • Tangerman, Albert (2009). "Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices". Journal of Chromatography B. 877 (28): 3366–3377. doi:10.1016/j.jchromb.2009.05.026