Dangerous learning: CSB safety bulletin cautions against certain lab demonstrations
The U.S. Chemical Safety Board (CSB) has released a safety bulletin called “Key Lessons for Preventing Incidents from Flammable Chemicals in Educational Demonstrations” based on three recent serious incidents in Nevada, Colorado, and Illinois where children were burned while observing laboratory demonstrations involving flammable liquid methanol.
Demonstrations of flames
The first incident described in the CSB safety bulletin is the September 3, 2014, accident at the Terry Lee Wells Discovery Museum, known as “The Discovery,” in Reno, Nevada, where thirteen people, most of them children, were injured. Two CSB investigators were deployed to the site and interviewed personnel who were directly involved.Just 12 days after the fire in Nevada, a second similar accident occurred on September 15th at the SMART Academy in Denver, Colorado, severely burning a 16-year-old high school student. Most recently, on October 20, 2014, less than five weeks after the incident at SMART, three Cub Scouts and one adult were injured during a demonstration using methanol at a Cub Scout event in Raymond, Illinois.
All the incidents involved demonstrations of flames – usually with a color additive – using methanol as the flammable liquid. In all three cases there was a flash back to the methanol bulk containers, and fire engulfed members of the viewing audience who were not protected by any physical barriers.
The safety bulletin notes that these incidents are similar to others the CSB has identified in which laboratory demonstrations involving flammable materials have resulted in fires and injuries. These include a 2006 accident at an Ohio high school that severely burned then-15-year-old student Calais Weber. The accident took place during a demonstration of a chemical “rainbow” that involved combusting salts with methanol. Calais’ story was described in a CSB safety video released in December 2013, called “After the Rainbow.”
A "fire tornado"
The CSB found that the accident at The Discovery took place during a “fire tornado” demonstration, where salts of different elements are burned in a dish along with methanol-soaked cotton balls, while spinning on a rotating tray. This produces a colored flame that looks like a tornado.
However, on the day of the accident the cotton failed to catch fire as expected. Additional methanol was added from a four-liter (about a gallon) bottle. CSB investigators determined that unbeknownst to museum personnel, the cotton ball was likely already smoldering, which ignited the freshly added methanol. A flash fire raced back into the large bottle - and burning methanol from the bottle sprayed toward the nearby audience of adults and children.
CSB Chairperson Rafael Moure-Eraso said, “ When performed safely these kinds of demonstrations can engage students and visitors and stimulate their interest in science. But methanol, the hazardous chemical involved in The Discovery and two other recent incidents the CSB has investigated, is classified as a highly flammable liquid, and users should adopt strict safety controls.”
Methanol can ignite at room temperature and has the potential for dangerous flash fires, especially when large quantities are present. The threat is quite similar to gasoline. However, CSB investigators learned that methanol is readily sold to schools and museums in four-liter containers.
Learning from YouTube video has limitations
The CSB also found that The Discovery developed the fire tornado demonstration based on YouTube video and additional online resources, where descriptions of accident risks or comprehensive safety instructions were not provided. And museum personnel who wrote procedures for the demonstration did not have an adequate background in chemistry or safety. The demonstration was performed approximately 15 feet away from museum visitors, with no barrier between the audience and the flames.
Similarly the CSB found that in the incident at SMART in Denver, the school lacked adequate safety procedures and a lab safety training program. The accident occurred during a demonstration activity of flammable properties which involved igniting a small pool of methanol to create a flame. When the flame did not rise as high as anticipated, additional methanol was added from a four-liter bulk container resulting in a 12 foot flash fire.
No training for teacher
The CSB found that the teacher was not aware of the potential for a methanol flash fire and had received no training about the hazards related to demonstrations involving large quantities of methanol or other flammable materials. This incident resulted in four students being burned in the flash fire, one seriously.
Likewise the October 20, 2014, accident demonstration at a Cub Scout event in Raymond, Illinois, occurred when methanol was poured from a container onto boric acid near an open flame. Similar to other incidents, the flame propagated back into the bottle and resulted in a flash fire that burned members of the group and seriously injured one Cub Scout. Like The Discovery incident, this demonstration involved burning methanol with boric acid to produce a green colored flame.
The CSB safety bulletin outlines key lessons learned as a result of the CSB’s investigation into these incidents:
- Due to flash fire hazards and the potential for serious injuries, do not use bulk containers of flammable chemicals in educational demonstrations when small quantities are sufficient
- Employers should implement strict safety controls when demonstrations necessitate handling hazardous chemicals — including written procedures, effective training, and the required use of appropriate personal protective equipment for all participants
- Conduct a comprehensive hazard review prior to performing any educational demonstration
- Provide a safety barrier between the demonstration and the audience
Chairperson Rafael Moure-Erason said, “These key lessons, if followed, will prevent future injuries. Educators should substitute or minimize the use of flammable chemicals and perform an effective hazard review prior to conducting an educational demonstration. Safety must be the absolute priority and educators should demonstrate chemical safety concepts as well as the science topic.”