All solvent based paints Alkyd resins, enamels, lucites, cellulose lacquers, water bourne enamels and shellac all have solvents in them that are flamable, toxic and depending on the type of solvent and the quantity and how you are exposing yourself to it have different effects on the liver, kidneys, skin, lungs, throat, sinuses, nervous system, etc. All paint products have info on the label regarding their toxicity and what you need to do to protect yourself.
If there is no info on the container you can ask your supplier for a Material Safety Data Sheet (MSDS) this will tell you what the product has in it, what it does to your body, how to protect yourself and whether or not it remains toxic after it is dried.
If you ask me a particular product I can look it up for you (requests within reason, I have a life)
I strongly recommend using a respirator when using anything that produces fumes, vapor or dust. Better safe than sorry and it cuts down on the boogers. Also, judging from all the beer you guys talk about drinking(me too) I'd thing you have better things to metabolize with your livers than Methyl ethyl ketone.
Eric '62 serII