The California State Assembly has passed legislation sponsored by Environmental Working Group and Earthworks to require oil and natural gas drillers to make public a complete list of chemicals they use in oil and natural gas hydraulic fracturing (“fracking”) operations. The fracking issue has raised alarms in communities nationwide because some chemicals injected into the earth to break up rock formations and free oil and gas are known human carcinogens such as benzene, xylene, toluene and diesel fuel.