Unfortunately (or fortunately, depending on your view) this just isn't the way the world works. Professional labs in industry and government do not rely on case-by-case risk assessments by staff scientists when it comes to safety. There is usually a blanket precautionary safety policy/plan that assumes that labs are a dangerous environment where unexpected things can happen. Professional scientists can sometimes take offense at these policies, interpreting them as an unfounded assumption by the organization that the scientists are not smart enough to determine whether an activity is safe or not. Maybe its a valid complaint, but when you get down to it, it's not really what the organization is doing, and as has been said here already, unexpected things happen in a lab, so even good risk assessments only get you so far in preventing accidents anyway. Still, I know a lot of professional scientists rebel against these policies and don't comply.
There's a valid complaint to be made that over reliance on blanket policies teach younger scientists not to be aware or evaluate the potential dangers of what they are doing, leading to a culture of complacency and reliance on precautionary policies rather than personal vigilance to ensure safety. On the other hand, there's also a valid point to be made that a person can't anticipate every source of risk in a constantly shifting laboratory environment that usually has a lot of moving parts (literally and figuratively). I've been working in a professional lab for many years, and while I like to think I am at least generally aware of the dangers of what I'm doing, I'd be lying if I said that I stop and do an in depth risk analysis of every lab activity I plan, and nor do I go around and ask everyone else in the lab what they are doing or do a detailed risk analysis for potential collateral damage. I, and I assume most professional scientists, operate largely by intuition and experience. Which is great and usually works to my advantage, but let's be honest, experience can itself often lead to complacency... what's the old adage - confident, cocky, lazy, dead? Automatically putting on PPE when I get in the lab at least gives me basic protections against my own complacency, and leaves me free to deal with the more unusual hazards that go along with specialized experiments that I might be doing on any given day.
Ultimately there's no scientific answer to what is the right balance of the need to protect (often inexperienced) laboratory workers from unseen dangers and the burden and expense of training individuals, buying PPE, and enforcing safety policies. One thing is for sure though: organizations that have professional labs will likely continue to err on the side of precaution because of the legal and regulatory framework within which these organizations must operate. A cynic may rightly claim that the policies exist not to protect the health of scientists but rather the bottom lines of the organizations that employ them. That's a little TOO cynical for me, but it's almost certainly an important consideration in drafting and enforcing safety policies (in fact, a lot of safety policies are legally required by organizations like OSHA in the US, so blame the nanny state if that's your bag).
Getting back to the main point - whether or not you should enforce laboratory safety policies as a primary school educator I guess is up to you. If your goal as an educator is to just teach the science - you are probably right, no harm is likely to come to the students by doing this experiment without safety goggles. (There's no point in getting angry at companies that publish lab procedures, though - for them its a matter of liability, and of course they are going to remind you to wear safety gear, no matter how innocuous the procedure sounds. It costs nothing to publish a few lines about putting on safety goggles and protect yourself from ridiculous lawsuits.) But you are simply way off base when it comes to the realities of working in a professional laboratory environment. Like it or not, blanket safety policies are the norm, and if your goal as an educator is to prepare students to become professional scientists and integrate them into what it's like to work in an industry or government lab, then you may well consider the value of getting them used to the culture and environment of professional science in addition to teaching scientific principles.
A few years ago I helped my daughter do a
science fair project at home. It was on browning of cookies. Certainly there are few "real hazards" involved that would necessitate PPE, at least none beyond what you encounter in daily food prep. (Interesting side point: why don't we wear goggles and lab coats for our more prevalent chemistry experiments in the home? I.e., cooking. On the other hand, I certainly wear safety goggles when charging my wet cell battery with acid at home. So at home I do case-by-case risk assessments). But we wore safety goggles anyway. Why? I told her it's because when you're doing a "real science" experiment, you always wear protection. I didn't even think about it. I guess that's a way of showing that, for good or ill, I've become accustomed to the culture of laboratory science to the extent that it's automatic, part of the uniform. On the other hand, she thought it was great fun to dress up like a scientist like daddy does every day. So, while you're doing all this whining and complaining about the injustice of having to wear goggles for an M&M experiment, you may consider that your students might actually like wearing the PPE or the way it conveys a sense of importance.
When I put my lab coat and safety goggles on at work, I admit to feeling like I'm gearing up to do something meaningful.
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Topic: Lab safety - false warnings. (Read 19173 times)