Naptha has been banned around here for about twenty years, along with other conspicuous smog-formers. Staggering quantities of related chemicals were once used in the area. The regulation has nothing to due with human heath and carcinogens (which is the responsibility of the EPA), but with
smog per se, per Calif Air Resources. If you don't like these regulations, then you can always move
to Bakerfield or Houston and cough and wheez.