Is it true that you can set a puddle of gasoline on fire with a cigarette thrown into it?

In many action-packed films you can see how a seemingly harmless cigarette butt becomes the cause of a fire. We checked how realistic such scenes are.

In Eldar Ryazanov’s film “The Incredible Adventures of Italians in Russia” (1973) there is a famous episode, in which Tano Cimarosa's character throws a smoldering cigar towards a gas station. A few moments after the cigar lands in a puddle of gasoline, the station takes off into the air. This technique has gained no less popularity in the West - for example, it can be seen in the beginning of the film “The Usual Suspects» (1995), as well as in key scenes of the films "Pay» (1999) with Mel Gibson and "3000 miles to Graceland» (2001) with Kevin Costner.

It may seem to the average person that the answer to this question can be easily obtained by comparing two numbers. Temperature at the tip of a lit cigarette - in the region of 700–950 °C. Temperature gasoline combustion - around 232 °C. It seems that this ratio does not promise any obstacles. However, let's see how things work in practice.

In 2013, Fire Technology magazine published study Howard Marcus and Justin Gaiman of the Bureau of Alcohol, Tobacco, Firearms and Explosives of the US Department of Justice. The purpose of the study was practical - according to statistics, about 2,400 residential fires in the United States annually are associated with gasoline, and half of them are classified as intentional. Experimenters made more than 4,500 attempts to ignite gasoline using smoldering cigarettes of various brands, but none of them were successful. And this despite the fact that the most different conditions were created - a cigarette butt was thrown into a puddle, into a container with gasoline, or vapors of this substance were sprayed in its direction. As tests have shown, the reason for the failure is that the temperature of the cigarette drops significantly at the moment when it is not inhaled. In addition, the main ignition hazard is not the gasoline itself, but its vapor. In the open air (for example, at a gas station), the probability of the required concentration of these vapors (1–6%) is extremely low. In addition, according to scientists, fire is also prevented by the rapid formation of ash on the cigarette. In other words, to set a gasoline puddle on fire, you need to take a drag from a cigarette near its surface.

Long before scientists, back in 2005, the hosts of the show “MythBusters” came to a similar conclusion. In a special release, dedicated to Hollywood cliches, they found that a cigarette can potentially ignite gasoline in an open container, but it will only have enough temperature for this at the moment of inhaling. Thus, ignition was regarded as very unlikely, and such attempts are fraught with serious burns to the face.

The methods of the show “MythBusters” are not always convincing from a scientific point of view (in this case, at least due to their much smaller scale), so it would be redundant to mention this program against the background of a scientific article. If not for one important circumstance.

In September 1986, a fire broke out in an apartment building on the southwest side of Chicago. fire, which killed brothers Guadalupe and Julio Martinez. The surviving Martinez siblings told police that their neighbor had previously threatened to set the building on fire in retaliation for the death of her brother, who was believed to be the victim of a Latino gang. However, the neighbor and several other local residents pointed to an 18-year-old boy named John Galven. And although the young man had an alibi (he was sleeping with his grandmother on the night of the fire), the police eventually arrested him and several people close to him. The fact is that the detective in charge of the interrogation handcuffed Galven to the wall and literally tricked him into confessing, promising freedom in exchange for the surrender of his “accomplices.” One of the important elements of the case was the establishment of the circumstances of the arson - as stated, the teenagers threw a bottle of gasoline on the porch and then threw a cigarette butt into the resulting puddle. As a result, three guys aged 18, 20 and 22 were sentenced to life imprisonment.

21 years have passed. One day, John Galven watched another episode of the show “MythBusters” in his cell - the same one we told you about above. He hastily contacted his lawyer, who was preparing the grounds for her third motion to reconsider Galven's case. The timing coincided with news that the detective who interviewed 18-year-old Galven had been caught in other cases of forced confession. Shortly before this, the same Bureau of Alcohol, Tobacco, Firearms and Explosives conducted experiment, only on a smaller scale than years later (2000 attempts instead of 4500). All experiments failed, but Galven's battle with the judicial system lasted for many more years. In 2017, a hearing was held at which an arson expert spoke in favor of Galven, and only this year, 2022, the three victims received a final verdict. acquittal sentence - after a total of 105 years in prison for a crime they did not commit. And although an important motive for re-examining the case was the criminal behavior of the police detective, natural scientific arguments also played a role in the verdict. You cannot set a gasoline puddle on fire with a thrown cigarette butt. At the same time, smoking is still usually prohibited at gas stations - if only because a match or lighter. Anyway, We categorically do not recommend conducting such experiments on your own.

Cover photo: Flickr

Not true

What do our verdicts mean?