Fart lighting is the practice of igniting the gases produced by human flatulence, often producing a flame of a blue hue, hence the act being known colloquially as a "blue angel", "blue dart", or in Australia, a "blue flame". The fact that flatus is flammable, and the actual combustion of it through this practice, gives rise to much humorous derivation. Other colors of flame such as orange and yellow are possible with the color dependent on the mixture of gases formed in the colon.
In 1999 author Jim Dawson argued that fart lighting has been a novelty practice primarily among young men or college students for decades, but is discouraged for its potential for causing injury. Such experiments typically occur on camping trips and in single-sex group residences, such as tree-houses, dormitories, or fraternity houses. With the advent of video sharing features online, hundreds of self-produced videos, both documentary as well as spoof, have been posted to sites such as YouTube. The people appearing in the videos are predominantly young males. In his book The Curse of the Self: Self-Awareness, Egotism, and the Quality of Human Life author Mark Richard Leary explains how a great deal of unhappiness is due to people's inability to exert control over their thoughts and behavior and that "stupid stunts", including lighting flatulence, were a way to make an impression and be included in group bonding or hazing.
Methane burns in oxygen forming water and carbon dioxide often producing a blue hue (ΔHc = -891 kJ/mol), as:
CH 4(g) + 2O 2(g) → CO 2(g) + 2H 2O(g)
Hydrogen sulfide also combusts (ΔHc = -519 kJ/mol) to
2H 2S(g) + 3O 2(g) → 2SO 2(g) + 2H 2O(g)
The odor associated with flatus is due to hydrogen sulfide, skatole, indole, volatile amines and short-chain fatty acids. These substances are detectable by olfactory neurons in concentrations as low as 10 parts per billion, hydrogen sulfide being the most detectable.
Some of the gases are produced by bacteria which live in symbiosis within the large intestines of humans and other mammals. The gases are created as a by-product of the bacteria's digestion of food into relatively simpler substances. The oxygen and nitrogen component of flatus can be accounted for by aerophagy, while the CO2 component results from the reaction of stomach acids (HCl) with pancreatic bile (NaHCO3).
Because the methane, hydrogen sulfide, and hydrogen present are flammable, igniting the resulting gases can result in burns or explosions as well as the desired flame. Clothing, hair, or skin may catch fire and skin tissue can be damaged.
In popular culture
Many find a comedic value in fart lighting and the activity is increasingly represented in pop culture possibly because "for adults, the allure of the vulgar is regressionary and often secretly pleasurable." Fart lighting has been a novelty practice primarily among males or college students for decades.
Radio personality Howard Stern cites a fart-lighting scene for losing his popular show's first NBC affiliate when WVIT in Hartford canceled the show.
In the 1999 episode "Spontaneous Combustion" of South Park, spontaneous human combustion is attributed to people's flatulence acting as the ignition. Shortly after the characters are introduced, one character, Kenny McCormick dies after attempting to light one of his own farts on a dare. (His deaths from odd causes are a running gag in the series). The children make this dare in response to seeing Terrance and Phillip light each other's flatulence in the movie-within-the-movie, Asses of Fire. The entire town is admonished to not to hold in their flatulence even in social situations where the practice could be inappropriate. Also, in the very first episode of South Park - "Cartman Gets an Anal Probe" - Cartman shoots fire out of his sphincter by virtue of an alien satellite dish inserted in his rectum.
A Bud Light 2004 Super Bowl commercial featured a horse-drawn carriage in which a couple is building romance and the man hands a woman a lit candle. While he leans down to retrieve the Bud Light; the horse farts and the gases, ignited by the candle flame, cause an explosion and we see the results of the woman's "blown out" hair and soot-covered face. At the end of the commercial, a passer-by refers to it as a "Rocket Sleigh".
In the 1996 film Jack, the title character who is portrayed by Robin Williams, and his friends from school ignite farts in a tree house.
In the film Beavis and Butt-head Do America (1996) the pair encounter their fathers in the desert. Over the encounter, the elder man resembling Butt-head offers to show something really cool, then farts into the campfire with atomic results.
In the April 2007 episode "Aunt Myra Doesn't Pee a Lot" of the sitcom Two and a Half Men, Jake's dad Alan asks how did Jake get candle wax on his pants, Jake confirms is was due to his lighting farts.
On 2 May 2000, a U.S. patent was issued for a "Toy gas fired missile and launcher assembly", a product that would allow one's "colonic gases" to be stored for later ignition to "fire the missile into space."
^Zanakis, Michael F.; Philip A. Femano (2 May 2000). "Toy Gas Fired Missile and Launcher Assembly". U.S. Patent Office, Patent number: 6055910; Filing date: Jun 1, 1998; International Classification - F42B 406. Retrieved 2008-01-10.