Sent in by Pauline
Editor: We've done a bit of research and it doesn't look good. We're not sure exactly which brand of epoxy coating you're considering, but we've looked at MSDS sheets for three different brands, and they're all essentially similar, with warnings to wear a respirator and cover all exposed skin.
That means the vapors from a product like the ones we researched can enter your body through your skin and affect your nervous system. The good news is that epoxy means a catalyzed reaction, which means the product cures relatively quickly, and then nearly all offgassing stops.
So should you do it? Based on the information we found, our verdict is no. We'd think twice about hiring someone to put an epoxy floor in our home, and we certainly wouldn't do it ourselves. But you should ask for the MSDS for the product you are considering: companies are required to give them to consumers upon request, and they're written in plain English, so they're relatively easy to understand.
What instead? Several companies make paint that can be used on raw concrete, including AFM, which makes a product called Concrete/Floor Paint (it used to be called Deckote). That, or another paint over a top-quality primer, plus a few layers of water-based polyurethane finish, will likely give you a finish that will function nearly as well as epoxy... and one that's a lot safer to apply.
Image via the CDC's page on NIOSH-approved respirators... the only kind you should wear when working with hazardous materials