The U.S. Chemical Safety Board has urged museums and schools to stop using methanol and other flammable chemicals in science demonstrations in light of a flash fire that injured 13 people, most of them children, at museum earlier this month. (Associated Press)
Read this statement from the U.S. Chemical Safety Board and watch this video from Flinn Scientific about unsafe use of methanol in chemistry demonstrations.
- What is methanol? Is it used for anything besides science experiments?
- Methanol is an organic compound that is, according to the EPA, mostly used to make other chemicals, including biodiesel, inks, plastics, dyes, paints, and pharmaceuticals. Methanol is also used as an automobile antifreeze, and fuel in specialized vehicles such as Monster Trucks and Champ Cars. Click here to learn more about methanol as a fuel.
- Methanol is an alcohol—methyl alcohol. However, it is incredibly toxic and not ever used for consumption.
- Many chemistry demonstrations use methanol as an accelerant to show flames of different colors. What is an accelerant? How can one accelerant produce flames of different colors? What is the point of this demonstration?
- As its name implies, an accelerant can speed up (accelerate) a chemical reaction. Methanol is an excellent accelerant to show colored flames because it is highly flammable and burns nearly invisibly.
- In these demonstrations, the methanol is not producing the flames of different colors all by itself. Methanol burns nearly invisibly, so the colors are actually being emitted by the other substances being burned. (Chemists who make fireworks know all about this!) In the case of the museum in Reno, that substance was boric acid, which burns green.
- The point of the experiment is to demonstrate that flames “are as distinctive to each element as fingerprints are to people.”
- Thermal energy excites the electrons in an element’s atoms to a higher energy state (orbital). These electrons cannot remain in this excited state for too long and will emit energy in the form of light (photons) to return to their more stable, grounded state. The color of the light emitted depends on the energies of the photons emitted, which are in turn are determined by the energies required to move electrons from one orbital to another. Read this terrific little article from the brainiacs at Scientific American for a better explanation!
- A picture as pretty as this is worth a thousand words.
- Using methanol in school and museum science demonstrations has a long history. If a school or institution is not ready to listen to the U.S. Chemical Safety Board, what are some safety precautions all educators should follow when conducting experiments with methanol? (Watch the video above for some hints.)
- Follow a safety checklist! Here’s a good one from the good folks at NSTA, and here’s one to share with students.
- The chemists in the video suggest some general precautions:
- Always conduct experiments and demonstrations in a clean, well-defined space, and never have students or participants very close to the chemical reaction.
- Always make sure students and participants wear protective gear—including safety goggles and hairnets.
- Dispense alcohol (such as methanol) in small amounts.
- Cap the bottle of alcohol and move it far away from the experiment.
- Never add fuel to a fire. Do not pour alcohol onto a hot surface, flame, or other ignition source. Never add alcohol once a demonstration is underway.
- Get certified! Flinn Scientific offers free lab-safety certification courses.