I work in a chemistry lab, Fri-Sat-Sun from 11 pm to 11 am.
Before I get to the lesson, I should caveat that on Sunday, I had a nasty stomach sickness, not sure why, but I only got about 2 hours of sleep in. Keep in mind this is after putting in 12 hrs Sat. night/Sun morning. Anyway, it was about 1050 am on Monday, so I had 10 minutes before I got off work. Rather than doing nothing, I decided to fill some repipetting jugs with their corresponding chemicals. I got to the potassium thiocyanate jug, started pouring.....KABLAM!! It was like the 4th of july. liquid shooting straight to the ceiling, a huge white cloud...etc... The lab was evacuated. Air tests confirmed the presence of cyanide gas, which makes sense, since potassium thiocyanate was one of the reactants. After the dust settled, so-to-speak, we found out that I had inadvertantly poured 30% hydrogen peroxide into the KSCN bottle. Being a strong oxider, it reacted violently, producing HCN, SO2 and who knows what else. Fortunately, no one got hurt from the incident. I finally got to go home at 1:15, truly exhausted and truly embarassed. The lesson: double check your labels when pouring from one container to another. Oh, and if you only get 2 hours of sleep prior to starting a 12 hour night shift, you might just want to consider calling in sick. I was going to, but changed my mind at the last minute.