Can you please tell me why it'sthat according to the state of california everything causes cancer?

It's stupid. America has a gravely dysfunctional tort law system that is ruining things for everybody but lawyers. Scientific illiteracy extends high in government. Since essentially any substance can be made to cause cancer in lab animals at ridiculous doses, the warnings were developed to try to keep lawsuits at bay. The real losers are good, ordinary, confused people.