Why is oil paint illegal?

Oil paint is not illegal in general, but oil-based paints have been restricted or banned in some areas due to VOC regulations and environmental concerns, leading to myth that oil paint is illegal. Oil-based alkyd paints contain high levels of volatile organic compounds, VOCs, which contribute to air pollution and smog, so many states like California and regions have strict VOC limits, banning sale of high VOC oil-based paints for architectural use, requiring low VOC alternatives like water-based latex or waterborne alkyd. Some municipalities restrict use of oil-based paints for exterior due to environmental rules. Artist oil paints are not illegal, but some pigments containing lead, cadmium, or cobalt may be restricted. Also, oil-based paints are flammable due to solvents, so storage regulations apply. So oil paint is not illegal everywhere, but high VOC oil-based house paints are banned or restricted in many US states and EU due to environmental laws, which is why many think oil paint is illegal. You can still buy oil-based alkyd enamel in many states for industrial and trim use, but low VOC versions are required in strict areas. So reason for restriction is VOC air pollution, not that oil paint itself is illegal.