I looked at a number of sources of MSDS sheets for MEK and posted that one because it gave the most detail. All of the others I saw were quite similar with regard to MEK being (not) a carcinogen. Although not particularly carcinogenic, I wouldn't advise taking a bath in the stuff. In high concentrations, it can do some significant damage to liver and other organs. It is easily ingested by inhalation and by absorption through the skin. I seriously doubt that it is worse than CA, gasoline, laquer thinner, butyrate dope, some epoxies, nitromethane, lead-based solders, soldering/brazing flux, some paints, polyester resin (and hardener/catalyst), chrome plating solutions, cadmium from NiCads or lead from lead-acid batteries - to name a few things that hobbiests are routinely exposed to.

If you find a reference to an MSDS that is very different, please post the link. Not all information sources are the same and if there is another scientifically valid document out there, you would do us all a favor by posting it. More information is always better than less!

Ross