Acrylic paint is water-based, so it is not flammable. Oil-based formulas, on the other hand, such as polyurethane, alkyd and varnish, are flammable. Both water- and oil-based media, however, contain pigments that are hazardous when not properly disposed.
Unlike oil paint, which uses natural oil as the binding medium for the pigment, acrylic paint contains synthetic resin. Because of this, it dries quickly and is soluble in water. However, unlike watercolor paint, acrylic paint is no longer water-soluble once dried.
Acrylic paint had been produced in Germany as early as the 1920s and the 1930s, but it was only in the 1950s that it became a popular medium in the fine arts. One of the first masters who used it was David Hockney.