I am no chemist but regular paint is usually water based. You can paint all day and the fumes will not harm you. You can have paint on your hands and arms all day, wash it off, and typically wont show any signs of irratation. The incubator while not 100% air tight still is reletively self contained.
I can't imagine unless you were planning to spray it on with a power painter how it would have any ill effect.