I won't suggest that MEK (methyl ethyl Ketone) is good for you but in many respects it is not much different in terms of toxicity than any other solvent, including materials such as acetone that we use very casually. Certainly, it is far less toxic/carcinogenic than gasoline. The following link is to an MSDS sheet for MEK

http://www.chemvip.com/ChemVIP%20Active/Products5.nsf/($All)/CD18FB9B3A7C33E486256B4C00623E72/$File/NONE-EN-CEL-NA-MSDS-061.pdf?OpenElement

Ketone peroxides, on the other hand tend to be much worse.

Ross