Yet another methanol flash fire has occurred with injuries when a high school teacher was demonstrating the “rainbow” flame test (C&EN, Nov. 9, 2015, page 6). While “rainbow” demonstrations have been conducted safely many times, they become dangerous if a large bottle of methanol is brought back to the demonstration to add more methanol. This same mistake has been repeated many times with catastrophic results.
There are important lessons to be learned by all of us, and it will take all of us working together to fix the underlying problems. In my view the incidents occurred because the teachers did not recognize the hazard. They thought they were pouring liquid methanol from the large bottle. They did not recognize that there was an “invisible cloud” of methanol vapors above the liquid methanol that rolled out of the bottle first to contact an ignition source—completing the three requirements for a fire. The vapors followed the gas laws when ignited, expanding at least seven times in volume as temperature and pressure rose instantaneously, producing a flash fire that pushed across the room to contact students. This likely happened because these teachers didn’t have adequate safety education.
The big lesson learned is that undergraduates (tomorrow’s teachers, graduate students, scientists) need a solid safety laboratory education—the long-term fix. Today’s undergraduates get safety training, not a safety education. Safety education teaches the “why” behind hazards so the student can understand and learn to respect the need for safety. Understanding the “why” teaches students the basis for safety measures and rules—making them more likely to use and follow them.
Safety education teaches the student to think critically about safety. More than once, I have heard, “There’s not room in the curriculum” for safety education. We need to rethink our priorities, values, and ethics. Among various topics in chemistry, safety is the only one that can result in serious injuries or death if it is not taught or valued.
Safety education needs to be included in the chemistry curriculum from the very beginning, teaching principle-based safety: Recognize hazards, assess the risks of hazards, minimize the risks of hazards, and prepare for emergencies. Many of our science teachers only take a few courses in chemistry, so we need to get to them early and often to give them as much of a safety education as we can before they move on to other majors—it is clear that flammable hazards need to be understood by these students.
In the short term, we need to communicate to teachers across the country about the potential hazards of “rainbow” demonstrations and how to prevent these flash fires. Teaching about the hazards of flammable liquids such as methanol should be part of this effort.
Alas, many of these teachers make minimal salaries and cannot afford joining organizations such as the American Chemical Society and the National Science Teachers Association that can provide advice about safety. As a result, they are not getting the word. We should all consider going to our own local school systems to talk with administrators about the “rainbow” flame test so they can get the word to their teachers.
Robert H. Hill Jr.
Stone Mountain, Ga.
Editor’s note: Hill is a member of the ACS Committee on Chemical Safety and councilor of the ACS Division of Chemical Health & Safety.