The science experiment that caused a flash fire, injuring 17 children and a teacher at Merrol Hyde Magnet School on Wednesday was not a surprise to chemical safety experts across the country. They have been warning schools about unsafe lab demonstrations for years. 

Word traveled fast to members of the American Chemical Society, Division of Chemical Health and Safety. Samuella B. Sigmann, a lecturer and Chemical Hygiene Officer at Appalachian State University in North Carolina, monitors chemical safety incidents. She has documented 32 similar incidents at school labs across the country, that injured at least 164 children and teachers. 

The experiments used in schools have names like Green Flame, Rainbow Flame, Whoosher Bottle, and Alcohol Cannon, and all involve alcohol-fueled flame tests. 

Sigmann says, “Safety professionals have been watching and trying to figure out how to prevent teachers from using flammable solvents in classroom experiments and demonstrations without proper ventilation and preventative controls in place.”  

Exactly how the fire started on Wednesday has not been released by Sumner County Schools. But it involved a chemical reaction caused by mixing boric acid and ethyl alcohol, according to Dr. Berchaun Nicholls, the Emergency Room physician who decontaminated and treated half a dozen children for burns at TriStar Hendersonville Medical Center.

Safety alerts have come from the American Chemical Society, the U.S. Chemical Safety Board, the National Science Teachers Association and the National Fire Protection Agency, among others. For years, they have been warning teachers to use alternatives to alcohol- based flame tests or at least use safety equipment like fume hoods.  

Dr. Ken Roy, Chief Safety Compliance Advisor at the NSTA, says, “schools have a legal responsibility, under duty or standard of care, to make sure teachers are trained in how to work with, store and dispose of chemicals in a safer way before working in school science labs with students.”

He says before any experiment or demonstration, teachers must do a hazard analysis, a risk assessment and a review of safety actions with equipment like safety goggles and gloves on hand. And there should be a dry run first, without students in place. The NSTA provides many resources like its safety portal and safety blog to help teachers.

Roy is also Director of Environmental Health and Chemical Safety for Glastonbury Schools in Connecticut. He warns teachers should never do an experiment involving alcohol and an active flame or sparks out in the open on a demonstration desk.  If they must use alcohol, instead of a safer alternative, do it under a lab fume hood.

“The most damaging demonstrations result from flame jetting,” says Dr. Roy, “because you cannot always see the flame, especially with some alcohols like methanol. Your hair and clothes may catch on fire. Your skin can also be severely damaged!”     

The National Science Teachers Association published this warning about the Rainbow Demonstration in 2014: 

These demonstrations present a high risk level for flash fires and deflagrations that can cause series injuries to students and teachers. On an open laboratory desk, invisible flammable vapors can be ignited by a flame, a spark (including static electricity), or a hot surface. Teachers who conduct these types of demonstrations outside of a fume hood put themselves and their students at unnecessary and serious risk during this demonstration.

Sigmann is publishing a journal article that she hopes will get the attention of science teachers. she believes lab demonstrations that go bad are often not accidental. “These are not accidents because they’re preventable and we must include more chemical safety education in the K-12 science teacher curriculum so they learn to work safely with chemicals in their classes”

Dr. Roy also does expert witness work in lawsuits where students have been injured in the lab. He cautions, “Schools need to understand they and their teachers have potentially serious liability” 

Chemistry lab demonstration fires have injured students as far back as 1998 in 19 states, including California, Florida, Georgia, Michigan, Texas, Nevada and New York.  

Some of those students who sued have won millions in damages. Two teens seriously burned at Western Reserve Academy in Ohio settled a suit for $18.9 million. 

One of those students is Calais Weber, who was burned over 46% of her body during a Rainbow Experiment in 2006. Weber was 15 years old at the time. She made a video safety message about the potential dangers in high school chemistry labs, produced by the U.S. Chemical Safety Board.