Following up on the flash fire during a “tornado” demo in a Nevada museum, the U.S. Chemical Safety & Hazard Investigation Board released a statement today containing details of the incident and warning against using methanol in combustion demonstrations.
CSB investigators responded to the museum fire, and their description of what happened confirms what the Associated Press reported:
Our investigative team determined that the incident occurred during a “fire tornado” demonstration where salts of different elements were combusted in a dish in the presence of alcohol-soaked cotton balls, while spinning on a lazy Susan-type rotating tray. This produces a tornado-like colored flame that rises in the air. The incident happened during a version where boric acid was to be burned in the presence of a methanol-soaked cotton ball. When the cotton failed to ignite it was realized that it had not been adequately wetted with methanol. More methanol was added to the cotton from a four-liter (one gallon) plastic bottle. Unknown to personnel, the cotton ball was likely continuing to smolder, and it ignited the freshly added methanol and flashed back to the bottle. Burning methanol then sprayed from the bottle toward the nearby audience of adults and children visiting the museum.
The CSB statement, by chairman Rafael Moure-Eraso, goes on to say that:
Methanol is an essential chemical and an emerging energy resource with a multitude of important industrial and environmental uses. But in the cautionary words of Greg Dolan, CEO of the Methanol Institute, which represents the manufacturing community, “Like gasoline, methanol is a toxic and flammable chemical and should only be handled in appropriate settings, and that would certainly not include museums and classrooms.”
Methanol readily emits heavier-than-air flammable vapors and the liquid has a low flash point, meaning it can ignite at room temperature in the presence of an ignition source. This creates an unacceptable risk of flash fire whenever any appreciable quantities of methanol are handled in the open lab or classroom in the presence of pervasive ignition sources, such as open flames, heat sources, or sparks. There is also a significant risk of flashback to any nearby methanol bulk container, as was the case in this last incident in Reno, Nevada. …
Today I am calling on all schools, museums, and science educators to discontinue any use of bulk methanol – or other similar flammables – in lab demonstrations that involve combustion, open flames, or ignition sources. There are safer alternative ways to demonstrate the same scientific phenomena, and many teachers are already using them. Any use of methanol or other flammables should be either avoided completely or restricted to minimal amounts, which have been safely dispensed at remote locations. Bulk containers of flammable liquids must never be positioned or handled near viewing audiences, especially when there are potential ignition sources present.