Exploding the Rainbow

An advantage - and disadvantage - of online science

I get an email about an incident like this, a fire caused by a "rainbow" experiment, every few years, often with more far more tragic results. These tragedies never happen in an online chemistry class! What an easy selling point for academic administrators.

On the other hand, when one teaches future teachers who will be expected to provide rich and engaging live learning experiences, one feels an obligation to make sure they can walk into an on-ground lab and handle themselves, their chemicals, and their students with a realistic combination of confidence and caution. I can provide my online students with articles, videos and lectures about chemical safety, yet I am still uneasy. Perhaps it is a generational trait that I need the students to belly up to a fume hood sweating under protective gear, to resist the temptation to mouth pipette, to heft a stock bottle and re-store it safely, before I send them off to be the teacher, the guardian of class safety as well as the architect of amazing and wondrous adventures in science.

When I taught a blended "non-major" Consumer Chemistry class to undergraduates, I actually used a version of this experiment that was much less dramatic, required the expense of spectroscopes, and didn't work all the time, but involved nothing flammable (other than students themselves). It was done by student pairs rather than as a demonstration. After the experiment was over I had students compare their observations with a video of the more dramatic experiments and discuss safety considerations in the teaching lab. But I did have them working with open flame on rainbow day. And of course there were more days when no open flame was allowed because there were organic solvents in use. And did I mention that oxidizer cabinet?

How do we know how much risk is reasonable? Is any risk reasonable when you are reading about in a newspaper article or a blog? When you drop your own child or grandchild off at school?