A spray bottle filled with an unknown liquid was left on the shelf under the precision flat. It was left next to a random bottle on isopropyl alcohol, which doesn’t actually tell me anything because it was full and thus not the source of the spray bottle’s contents.
What is in this bottle? Water? Alcohol? A detergent? Something acidic or alkaline? Is it toxic? Flammable? I have no way of knowing, so I have to treat this bottle as a chemical hazard. It’s the only safe way to proceed.
Label your liquids. This has happened several times before, often with liquids that were obviously potentially toxic and caustic. (Best I can tell someone once mixed Simple Green with Ammonia, which is stupid on a variety of levels.) These had to be disposed of as chemical waste, because I couldn’t make assumptions about what they were.