: Older epoxies used solvents to reduce viscosity, and these organic solvents
: were malevolent compounds. The "100% solids" have no volatile
: organic solvents (MEK, toluene, xylene, MIBK, etc.) and so are far safer
: to work with. The epoxy resin is relatively harmless, but the curing
: agents, particularly the amine-based formulations found in most
: boatbuilding hardeners, can cause sensitization. Cycloaliphatic amines are
: nasty too, but you're not likely to run into them building boats. There is
: a far broader range of during agents and diluents than of epoxy resins.
: Curing agents come from all sorts of mineral and vegetable sources, and
: they are not benign. Their specialty is reacting with epoxy, but they're
: not particular about reacting with whatever else they bump into. If they
: can cause rash on your tough hide, imagine what they could do to your
: tender lung tissue. You can't go wrong by wearing a respirator. Make that
: a real one, with activated charcoal "Organic Vapor" cartridges,
: the black ones.

: This also applies when sanding epoxy, because the stuff frequently takes days
: for full cure, and a lungful of partially cured epoxy dust is much worse
: for you than the hardener fumes. Consider this. Asbestosis is a lung
: disease caused by breathing asbestos-like particles. Microscopically these
: particles are not much different than epoxy sanding dust. Notice the
: operative word "asbestoslike particles". It is not just the
: chemical composition of the particle that is harmful, but its size and
: shape. OSHA has determined that the TLV for this irritant is 0.00. There
: is no known safe concentration, infection can be caused randomly by just
: one discrete particle. There has been a lot of press here recently about
: Libby, Montana, where 3/4 of the population has some type of lung problem,
: from an asbestos mine 10 miles out of town that has been shut down for
: years.

: So what is the upside? Temporary comfort and convenience. The downside is
: nasty lingering death. Tough choice, huh?
Pete, so far the best reponse. Logical and to the point. You bring up another question, I used an asbestos cartridge(the pink ones) when sanding the epoxy. Do you think this was a safe enough choice. Also it has never neen a matter of comfort as I believe in safety, but as you are aware it is one more expense that if not needed... I'm talking about the black ones that you are referring to. Thanks for a reasonable response. Elliott