California Air Resources Board

An air pollution control device that traps particulates by forcing gas streams through large permeable bags usually made of glass fibers. For more information, visit our baghouse training website.

A provision in air district permit regulations that allows a facility to accumulate credits for reducing emissions beyond regulatory limits (emission reduction credits) and then use or sell those credits at a later date.

A vehicle that runs on electricity stored in batteries and has an electric motor rather than an internal combustion engine. These vehicles also meet the requirements of the Zero Emission Vehicle Regulation.

A term used to describe the "best" measures (according to U.S. EPA guidance) for controlling small or dispersed sources of particulate matter and other emissions from sources such as roadway dust, woodstoves and open burning.

The most up-to-date methods, systems, techniques and production processes available to achieve the greatest feasible emission reductions for given regulated air pollutants and processes. BACT is a requirement of NSR (New Source Review) and PSD (Prevention of Significant Deterioration). For more information, visit our BACT website.

An air emission limitation that applies to existing sources and is based on the maximum degree of reduction achievable, taking into account environmental, energy and economic impacts by each class or category of source. (See also Best Available Control Technology.)

Biological sources such as plants and animals that emit air pollutants such as volatile organic compounds. Examples of biogenic sources include animal management operations and oak and pine tree forests. (See also natural sources.)

An intermediate gasoline distribution facility where delivery of gasoline to and from the facility is solely by truck.

An agency of the California Department of Consumer Affairs that manages the implementation of the motor vehicle Inspection and Maintenance Program. For more information, visit our the Smog Check website.

A day that is not officially determined by meteorologists and air quality managers to be a no-burn day. Burn days vary by air basin on any given day.

A nonprofit association of the air pollution control officers from all 35 air quality agencies throughout California. CAPCOA was formed in 1975 to promote clean air and to provide a forum for sharing of knowledge, experience and information among the air quality regulatory agencies around the state. CAPCOA is an organization of air quality professionals -- leaders in their field -- who promote unity and efficiency and strive to encourage consistency in methods and practices of air pollution control. For more information, visit our CAPCOA's website.

The state's lead air quality agency consisting of an 11-member board appointed by the Governor, and just over thousand employees. ARB is responsible for attainment and maintenance of the state and federal air quality standards, California climate change programs, and is fully responsible for motor vehicle pollution control. It oversees county and regional air pollution management programs.

A legal limit that specifies the maximum level and time of exposure in the outdoor air for a given air pollutant and which is protective of human health and public welfare. CAAQSs are recommended by the OEHHA and adopted into regulation by the ARB. CAAQSs are the standards which must be met per the requirements of the California Clean Air Act (CCAA).

A California law passed in 1988 which provides the basis for air quality planning and regulation independent of federal regulations. A major element of the Act is the requirement that local air districts in violation of the CAAQS must prepare attainment plans that identify air quality problems, causes, trends and actions to be taken to attain and maintain California's air quality standards by the earliest practicable date.

A state government agency established in 1991 for unifying environmental activities related to public health protection in the State of California. There are five boards, departments and offices under the organization of Cal/EPA including the California Air Resources Board (ARB), State Water Resources Control Board (SWRCB) and its nine Regional Water Quality Control Boards (RWQCB), Department of Pesticide Regulation (DPR), Department of Toxic Substances Control (DTSC) and Office of Environmental Health Hazard Assessment (OEHHA). The Cal/EPA boards, departments and offices are directly responsible for implementing California environmental laws, or play a cooperative role with other regulatory agencies at regional, local, state and federal levels. For a full list of Cal/EPA organizations, see Cal/EPA's home page.

A California law that sets forth a process for public agencies to make informed decisions on discretionary project approvals. The process aids decision-makers to determine whether any environmental impacts are associated with a proposed project. It requires environmental impacts associated with a proposed project to be eliminated or reduced and that air quality mitigation measures are implemented.

An initiative to add hydrogen fueling infrastructure in California to meet the demands of hydrogen vehicles deployed in the state.P For more information, visit the California Hydrogen Highway Network website.

Gasoline sold, intended for sale, or made available for sale as a motor vehicle fuel in California subject to the California Phase 2 reformulated gasoline standards.

Gasoline sold, intended for sale, or made available for sale as a motor vehicle fuel in California subject to the California Phase 3 reformulated gasoline standards.

A petroleum-derived liquid that is intended to be a product that will become California reformulated gasoline upon the addition of an oxygenate, such as ethanol.

A California Public Utilities Commission investor-owned utility program initiated on January 1, 2007, to provide incentives for installing solar distributed generation projects.

A group of diseases characterized by uncontrolled invasive growth of body cells leading to the formation of malignant tumors that tend to grow rapidly and spread (i.e., metastasize).

An enforceable limit on total emissions for the facilities covered under the cap-and-trade program. The cap is set for each compliance period of the program by the state and emissions are reduced as the cap declines over time.

Cap-and-trade is a regulatory approach used to control pollution by setting a firm cap on allowed emissions while employing market mechanisms to achieve emissions reductions while driving costs down. In a cap-and-trade program, a limit, or cap is put on the amount of greenhouse gases that can be emitted.

Gasoline sold, intended for sale, or made available for sale as a motor vehicle fuel in California subject to the California reformulated gasoline standards.