Two New York city high school students suffered burns when a popular chemistry experiment sent a plume of fire across the science lab, leaving one 16-year-old in critical condition, The New York Times reports. The accident occurred less than a month after a federal safety agency created a video message for educators warning of the dangers of the demonstration.
The Beacon High School teacher, whom the Times described as “known for safety consciousness,” was performing the so-called “rainbow experiment,” which shows how different salts produce different colored flames when burned. In front of 30 students, she used methanol as an accelerant, and the experiment exploded. The two closest students were engulfed in flames—Alonzo Yanes was burned severely on his face and body and Julia Saltonstall “saw her thin T-shirt burned off her torso in an instant” and received more minor burns, the Times reports.
The recently issued video from the U.S. Chemical Safety Board, titled “After the Rainbow,” documents the experience of Calais Weber, who suffered severe burns on nearly half her body as a 15-year-old in 2006 when her chemistry teacher performed the same experiment. An investigator with the safety board told the New York Times that there have been at least seven similar incidents.
Ken Roy, the chief science safety compliance consultant for the National Science Teachers Association, told me that people have been doing the experiment for years, but it’s an unsafe one. “Methanol is absolutely unpredictable. It produces vapor clouds. If there is a spark or open flame it’s a death bomb.”
It is possible to make the experiment safer, he said in a phone interview, though not fully safe.
“I prefer people don’t do this. If you must, you should do it under a fume hood. There should be eye protection, and you never take methanol, a bottle of it, and pour it when you have an open flame.”
Roy said that teachers can show the variations in colors another way.
“You soak the salt with a wood splint and when it dries you put it in the burner,” he said. “There’s no methanol and it still gives off that characteristic color.” He also urges teachers to research safety online and to consult safety data sheets to understand the hazards of particular chemicals before using them.
You can find more of his suggestions in this NSTA blog post.