Chemists used to basically bathe in Benzene back in the day. I’ve heard that they as a group tended to die in their 60’s. Most teaching Chem labs tend to work with small amounts of chemicals today and try to avoid the nasty stuff if possible.
When I went to Belgium I visited
the Red Star Line museum The Red Star Line was a passenger ship company that brought millions of immigrants from Europe to the US in the early 20th century. In order to depart for the US, passengers were required to scrub themswlves down with benzene and let it soak in to kill any potential lice eggs.
Also their luggage was autoclaved (yep, with hot stean) and then drenched in disinfectant.
Benzene, C6H6 and Zyklon B (aka HCN) are very different chemicals and I'm not advocating HCN as a delousing agent. The difference is that the body copes with small amounts of HCN very well as small amounts can be naturally found in food whereas C6H6, an aromatic hydrocarbon, isn't. C6H6 does damage in an altogether different way and its effects are cumulative.
Incidentally, as I've mentioned in an earlier post I've always been very careful to avoid exposing myself to C6H6, but less so to HCN. I used to use HCN in photographic processing and as I mentioned once before on HN I was affected by its fumes—and I'm still here to mention the fact (but I'm not for a moment suggesting that people be lax when using the stuff).
