CARB’s Regulation for the Reporting of Criteria Air Pollutants and Toxic Air Contaminants

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CARB’s Regulation for the Reporting of Criteria Air Pollutants and Toxic Air Contaminants


The Regulation for the Reporting of Criteria Air Pollutants and Toxic Air Contaminants (known as the Criteria and Toxics Reporting Regulation, or CTR) was developed in response to Assembly Bill 617 (AB 617), which specified that CARB require the operators of stationary sources to annually report their emissions of criteria air pollutants and toxic air contaminants using a uniform statewide system of reporting. In addition, CTR was developed to meet the needs of numerous other CARB programs, like the community right-to-know tenets established in AB 197, and the toxic air contaminant emissions data necessary to evaluate health risks according to the AB 2588 “Hot Spots” program. 


Stationary sources of air pollution, like refineries, power plants, chrome plating shops, auto body shops and gas stations, emit a variety of air pollutants. For many types of stationary sources, the operator of the facility is required to obtain an operating permit from the local air district. Acquiring a stationary source permit involves many steps, including, but not limited to, determining compliance with all applicable rules and regulations, ensuring the appropriate level of emissions controls are applied, and estimating the potential airborne emissions from the facility.


While CTR does not establish any specific emission reduction requirements, CTR supports the efforts of other air quality programs by:

  • Increasing both the number of sources and the number of individual toxic air contaminants to be reported from stationary source facilities;
  • Establishing a consistent annual reporting frequency for facilities subject to CTR;
  • Providing the data needed to identify areas of concern throughout the state, leading to more information on pollution exposure in impacted communities; and 
  • Tracking progress in emissions reduction efforts

CTR establishes a process to identify facilities that should be included in the emissions inventory program, and requires those facilities to report emissions data. As an example, Figure 1 on the following page shows the facilities within the Southeast Los Angeles (SELA) Community that are currently providing annual emissions data, and Figure 2 shows the facilities that will be added to the inventory by 2027. Implementation of CTR reporting requirements will double the number of California facilities reporting emissions data to CARB from about 28,000 to over 60,000, over the course of seven years.  The figures below visually demonstrate CTR’s value. CTR will improve the quantity and quality of the emissions data that will be available to policy makers and the public.


Figure 1: SELA Facilities Reporting 2020 Emissions Data

The blue dots on this map represent the facilities that are currently on CARB’s pollution mapping tool. The yellow dots are additional facilities for which emissions data are available on CARB’s Facility Search Tool website.











Figure 2: SELA Facilities Reporting Annual Emissions in 2027

The dots on this map represent additional facilities for which emissions data will be available by 2027, when CTR is fully implemented.

Going Forward


Beginning in 2022 and continuing through 2028, the CTR phase-in process will substantially expand emissions reporting requirements for a majority of permitted facilities, increasing both the number of sources and the number of individual contaminants to be reported to CARB, until nearly every source of air pollution permitted by a California air district will be reporting on an annual basis.


CTR is a step forward in creating uniformity and consistency in emissions data reporting across the 35 air districts in California and ensuring the quality and completeness of emissions data. Reported emissions data from facilities forms the basis of CARB’s inventory of emissions data from stationary sources.


CARB will be working with facility operators, air districts, and others to implement CTR. Emissions data is available at CARB’s Facility Search Tool website at: https://ww2.arb.ca.gov/our-work/programs/ab-2588-air-toxics-hot-spots/facility-search-tool