Toxicity

I have been working with metals for about 2 years and have recently
become concerned (probably should have sooner) about the toxicity of
some of the substances I am working with. I am wondering if anyone
out there can clarify what is and is not harmful to touch or breathe.
Yesterday while spreading a mixture of boric acid and alcohol on a
piece, I thought I really should investigate this issue.

thanks - Lori