A commonly-performed chemistry demonstration at W. T. Woodson High left five students and a teacher injured on Friday morning after the experiment started an out-of-control fire. All of the students’ injuries were serious enough to warrant hospitalization, with two of the five being transported by helicopter. One student is in critical condition.

The experiment in question, commonly referred to as “the rainbow experiment”, is meant to show how the color of fire depends on the compound undergoing combustion. Similar experiments are virtually ubiquitous in high school level chemistry classes, with one even making an appearance in the TV show Breaking Bad.

The exact cause of the accident is not known with certainty. However, students present at the time of the accident describe the teacher “adding more alcohol straight from the bottle” in an attempt to keep the reaction going after the flame had begun to die down. Shortly thereafter, the students near the front of the room were suddenly engulfed in flames. One student describes it not as an explosion, but more of a “sideways fireball”.

 Of the 31 students and 2 teachers present, 5 students and one teacher were injured.
Following the accident, the school was evacuated. The fire was still burning by the time firefighters arrived and had damaged 50% of the room, but fortunately it was subdued before it spread further.

This is not the first time the rainbow fire experiment has caused accidents. According to the American Chemical Society, the demonstration should not be performed indoors. "These demonstrations present an unacceptable risk of flash fires and deflagrations that can cause serious injuries to students and teachers," the ACS said.

An extremely similar incident occurred in 2004. Once the colored flame began to die down, the teacher attempted to add more fuel before the small fire had completely gone out. That accident left a 15-year-old student with burns to 40% of her body. The student in question describes her experience in the video below.

The effort required to avoid this sort of accident is minuscule, and yet it continues to occur year after year. This serves to demonstrate the unfortunate reality that safety measures are often neglected at every level of chemistry. When accidents are uncommon it is very easy for even professionals to become complacent. Although it is vital to remain vigilant at every level, it may be especially true for those teaching younger students. Demonstrations at the elementary and high school levels are for more than sharing the beauty of chemistry. They are also an opportunity to lead by example, and to instill in students a healthy respect for the dangers involved.

Written by: Aisling Williams


Jackman, T., Shapiro, T. R., and Brown, E. (2015) Six injured in chemistry classroom fire at Woodson High School in Fairfax. Washington Post. The Washington Post.

(2015) Chemistry Experiment Sparked Explosion in Va. High School. NBC4 Washington.

Gilligan, Vince. "Breaking Bad - Pilot." Chemistry Class. HBO. N.d. YouTube. Web. 30 Oct. 2015

Matt Ackland (mattacklandfox5). Twitter.

USCSB. "After the Rainbow." YouTube. USCSB, 10 Dec. 2013. Web. 30 Oct. 2015.