I tis grainier than solvent based paint, and it is not safer by any means....it is NOT WATER BASED it is water bourne, meaning that water is the carrying agent for the pigments....and some of the pigments like phtallo blue are a carcenogin. Always use a mask, and ventilate.
It depends on what you are painting.....For automotive use, I don't recomend doing it at all because all of the paints are harmful in some way. But if you have to then use aut air as it is less flamable than solvent borne paints. But still as poisonous in a lot of cases.