Polymers, including natural proteins (such as DNA) and artificial materials (such as nylon and polyester), are examples of macromolecules. materials scientist Someone who studies the ways in which the atomic and molecular structure of a material relates to its overall properties.
Emission standards for engines and vehicles, including emission standards for greenhouse gas (GHG) emissions, are established by the US Environmental Protection Agency (EPA).The EPA authority to regulate engine emissionsâand the air quality in generalâis based on the Clean Air Act (CAA), most recently amended in 1990.ther states have a choice to either implement the federal emission standards, or else to adopt California requirements (CAA section 177).
Regulatory Authority. The Clean Air Act, as amended, both directs and authorizes the U.S EPA to establish standards regulating the emissions of mobile sources and to establish a compliance program to implement and enforce the mobile source emission control program.n establishing emission standards and elements of the compliance program, EPA must follow the requirements of the Clean Air Act and the Administrative Procedures Act in the Agency's rulemaking activities.