It depends on the coating, you will need to open the container and observe the coating. After gradually bringing frozen paint up to room temperature (70 degrees F), open the can and stir it. If the paint looks like a fresh, never-been-frozen can of the same product, it should be safe to use. When inspecting a thawed can of paint, be especially wary of lumps, thickening or solid pieces that can't be broken. If any are present, the paint should not be used. In general, it's best to prevent such problems by protecting paint - especially water-based latex paints - from freezing temperatures.