Clean Air Act (CAA): Primary federal air quality law that regulates air emissions from stationary and mobile sources. Authorizes EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and regulate emissions of hazardous air pollutants.

EPA Regulations: Environmental Protection Agency's implementing regulations for air quality and emissions control, including specific standards, monitoring requirements, and enforcement procedures.

National Ambient Air Quality Standards (NAAQS): EPA-established standards for six principal pollutants ('criteria' air pollutants) that set permissible levels of atmospheric concentration.

Mobile Source Emission Standards: Federal standards specifically governing emissions from vehicles and other mobile sources, including requirements for manufacturers and operators.

Federal Vehicle Emission Standards: Specific requirements for vehicle manufacturers regarding emission control systems and maximum emission levels for different vehicle categories.

State Implementation Plans (SIPs): State-level plans for meeting federal air quality standards, which may include additional or more stringent requirements than federal standards.

State Environmental Protection Laws: State-specific legislation governing environmental protection, which may impose additional requirements beyond federal regulations.

Local Air Quality Management Districts: Regional regulatory bodies that implement and enforce air quality regulations at the local level, often with authority to impose additional requirements.

California Emission Standards: Notably stricter vehicle emission standards set by California, which other states may choose to adopt instead of federal standards.

Industry-Specific Regulations: Sector-specific emission requirements that vary based on industry type, size, and potential environmental impact.

EPA Reporting Requirements: Mandatory reporting obligations for emissions data, compliance status, and environmental impact assessments to the Environmental Protection Agency.

Risk Management Provisions: Legal requirements for assessing, managing, and documenting emission-related risks and potential environmental impacts.

Environmental Impact Assessment: Requirements for evaluating and documenting the potential environmental effects of emissions and proposed mitigation measures.

Municipal Requirements: City or county-specific regulations that may impose additional emission control requirements or restrictions based on local conditions.