Substituting Funny Story

So I'm overseeing a group of IB Biology students on Wednesday. They are working on their projects and it's a pretty low-key day: responsible students so I don't have to get on their case too much. Then out of nowhere, one kid comes up and asks to use a scalpel. Probably a normal request in a Biology lab, but still one that causes hesitation. I respond by suggesting the use of scissors, which turned out to be totally appropriate since they were merely cutting braided nylon rope. A few minutes later, the same student with the same sheepishly apprehensive grin comes up and asks for some matches to light a Bunsen burner. I allowed myself to be talked into letting them use it, with the caveat that they would wear all the necessary protective equipment. A couple minutes later, you guessed it, the same student comes up asking if I know where the switch for the exhaust fan is. I don't have any clue. Starting to smell the smoke myself, I put the kibosh on the whole operation fearing that our classroom would trigger the fire alarm. Thankfully there was only 2 minutes left in the period. Whew!