Where shall I begin?
1). Making batteries in a general chemistry lab, when the period ended I was in a rush to get out of the lab and right to lunch. I wasn't really thinking too much at this point, and grabbed both the anode and the cathode of the battery at the same time. I got an incredible shock and my fingers were twitching for a few hours afterwards. Not fun.
2). In my analytical lab in college, I was doing the analysis of the metal content in a U.S. Nickel and was using both concentrated nitric and sulfuric acids for different parts of the analysis. Sadly, I didn't label my beakers. When the period ended and I went to clean up, I put my thumb into a beaker to pick it up with my already full hands. (Bad mistake). What I thought was water was actually 98% H2SO4! It started eating right through my thumbnail, and I really couldn't put it down quickly since the lab was very crowded. I finally managed to move over to the sink area so that I could put the beaker down in area where it wouldn't get knocked over, and also wash my thumb. Unfortuneately, some idiot forgot to put the cap on the bottle of concentrated nitric acid, so as I'm moving my full hands over towards the sink, my right forearm caught the top of the HNO3 bottle. I now have a very nice nitric acid scar on my right forearm that really hurt when I first got it. My thumb was pretty badly burned by the sulfuric acid, but the nail grew back and there's no permanent damage.
3). This one's not really an accident, but more of a chemical exposure incident. My freshman year of college I was responsible for the chemical inventory at my school. (I.E. I had to check and make sure that everything was there that was supposed to be, and nothing was in a dangerous state). The cyanide/cyanate/thiocyanate/etc. section was a very big section. I spent about four hours down there one day, and it was very damp and not very well ventillated. All you could smell was the odor of bitter almonds from the cyanide gasses in the air. (Mind you it wasn't at a lethal level, but you could notice the smell). For the next few days, I had a massive headache and no energy at all. That kind of sucked.
4). In an organic lab my sophomore year of college, we were working with that lovely diethyl ether stuff. Some of it spilled onto my jacket which I was wearing since it was nearly time to go. I used a paper towel and soaked up as much ether as I could, then I set it out by the fume hood so that it could evaporate away and not pose a hazard. Quite a few minutes later, when I finally got everything taken care of that I needed to, I went and got my jacket which was nice and dry and didn't appear to have an odor. I get outside and take out my cigarettes and my lighter. I go to light the cigarette when "WHOOOOOOSSSHHHHH" a big ball of flame engulfs me. It was a very quick flash, but all the hair on my face and my forearms were gone. Apparently there was still some ether vapors on my jacket which ignited when I lit the cigarette. Thankfully, there wasn't a whole lot and the hair on the top of my head didn't burn. It scared the bejesus out of me, however. (And I didn't notice the ether smell because I had been exposed to it for so long that my nose had grown numb).
5). My senior year of high school my chemistry teacher asked for volunteers for a chemistry demonstration to be given at night for the general public. I volunteered as I loved chemistry and she was putting me in charge of an alkali-metal demonstration. A friend of mine also was helping out, and he just wanted to put the biggest piece of sodium he could find in some water. He grabbed a chunk about the size of a large gumball and went to throw it in a small beaker filled with water. Seeing how if the sodium hit the water there would be a huge explosion, I quickly put my hand over the water and the sodium fell into my bare hand. I suffered some very minor chemical burns to the palm of my hand, but it could have been far worse. Still, that hurt like a mother-fu**er!
6). High School Chemistry Lab. We needed some glass tubing for a lab we were doing, and it needed to be bent in a specific configuration. All the school had was some old straight glass tubing that the previous chemistry teacher had used many, many, many years ago. So we had to go and bend the tubing in a flame. We started heating the tubing up and it began to turn a little bit yellow. Then it turned a brownish-red color, then it started emitting fumes as a red liquid dripped out the end. Apparently the tubes had been used to collect bromine in the past, and the bromine that seeped into the tubing was leeching out as it was heated. Sadly for me, I was between the tubing and the air vent in the ceiling and got a nice whiff of the bromine. It has a foul, horrendous, nasty odor that is appropriate for its name. It smelled exactly like a skunk that took a bath in bleach.
7). Yet another high school lab "accident." I needed to weight out a specific amount of sodium silicate for a lab were doing later in the week. (During my study hall I'd go into the chem lab and make solutions for my teacher since it was better than sitting on my ass in the library). I used the electronic balance and started to pour out the powdered sodium silicate. Unfortuneately, the silicate was in a VERY fine powder form and a lot of it became airborne. I inhaled a great deal of it and had a lot of trouble breathing. I quickly just went over to a window and tried to get some fresh air. The worst part about that is the fact that sodium silicate is right up there with asbestos. It's not something you want getting into your lungs.