I did say preciously that this was tert-butyl lithium. This is usually a solution that you have to very carefully syringe our of a bottle making sure that absolutely no air (it reacts violently with oxygen in the air) or moisture (the water vapor in the air) gets to it. If you ge this wrong it can catch fire. It is usually dissolved in what is essentially petrol, so very flammable. People have died using this.
Now you have asked again I remember a worse one….bis(trimethylsilyl)mercury. This is very similar to a very very very horrible compound dimethylmercury that did kill someone from a single drop on their glove:
It goes straight through the glove, the skin and into your blood. Mercury is very toxic in the blood. The compound I was using is supposed to be a lot less dangerous because it is a solid (a very evil green looking solid), not a liquid and it is very reactive so should breakdown before it can get into your blood. Still, nobody has ever tried to see how toxic it is for obvious reasons and logic tells us that it is likely to be game over if it did find its way through your skin…..never agian!
I should add that when you are a profesional chemist, despite how dangerous somethings potentially are, you can be focused and careful enough when handling compounds like this that the actual risk to you or anybody else is tiny. Way less than crossing the road probably. Also, nobody ever makes you do anything you don’t want. I researched the risks fully and made sure I understood completely what to do in all situations and chose to work with these compounds. Biologists face the same decisions when working with potentially very dangerous bacteria and viruses.