So we're undertaking a purge of our chemical stockrooms.
A few years ago, before I arrived, another teacher performed a chemical inventory, but nothing was removed and only a few things were marked for disposal. Hey, that's an interesting thing when we're talking about chemicals: disposal.
Depending on what it is, there are different ways to dispose of things. Flinn scientific lists more than thirty ways to dispose of whatever quantities of chemicals you may have left after performing a lab, or at the end of the year. Some get neutralized, some get double bagged, some get flushed with lots of running water. But when you've got forty years worth of chemicals stored up, many of which haven't been used in at least ten years, then disposal becomes a different matter.
step one: Remove the chemicals you don't intend to use in the next two years or so. We filled three lab benches worth and sorted them loosely: flammables, acids, bases, organic, inorganic, solutions, solutions with heavy metals, unknowns. We moved prolly one hundred or so flasks, jars, and beakers of stuff. And we kept finding more.
Why, oh why, do we have five jars of potassium permanganate solution? Why do we have six of ferric chloride, and twelve of potassium thiocyanate? Five jars of potassium nitrate in my little stock room alone. And why is this flask of red solution labeled H2O? What IS this purple stuff?
step two: Evaluation. The next day, a rep from an environmental services company came to look at our waste and estimate the cost for disposing of all of it. We imagined best case scenarios (they take it all right now for $20!) and worst case scenarios (they gasp in horror, clutch their pearls, refuse to take any of it, and fine us for endangering students!).
What happened was somewhere in the middle, of course. The rep segregated everything by hazard class, noting that we had a little something in every single hazard class -- from low level stuff that we could flush on our own, to high hazard stuff that will need a bomb squad just to open it and determine if they can transport it. I'm not even kidding about the bomb squad.
step three: Wait. I wait to see how much they want to charge us to get rid of all this stuff. And there are two very important lessons I've learned.
First, don't purchase chemicals without considering its future disposal. Seriously, this is a good idea for everyone pollution-wise. Don't go ahead and do stuff now without thinking about who has to deal with it later.
Second, for pete's sake, teachers! Stop labeling things as unknown! Yes, you want your students to figure it out in the lab, but when you've been gone for five years I'm not playing a game of guess the ions just to clean up your mess!