Individual states are allowed to implement regulations for themselves unless the federal EPA has developed a national regulation that covers the issue. States can be more restrictive than the EPA, but they cannot require something that conflicts with federal requirements. California has implemented Proposition 65 that requires labels alerting consumers that the product contains an ingredient that is either a carcinogen or a reproductive toxicant. This warning shows up in many places; the easiest to see is the label on refueling pumps at gas stations. Do you think that these types of initiatives are useful? Why, or why not?