Air Toxics Overview | AB 2588 Air Toxics “Hot Spots” Program | Air Toxics and Health | Air Toxics for Business | Air Toxics Regulations

Advisories

• 1/29/26:  The District’s DICE Screening Tool, User Guide and Background Document for performing diesel engine HRA screenings were updated.  See the District’s DICE Health Risk Assessment Screening Tool (opens in a new tab) webpage for more information.
• 1/26/26:  The District’s Approved Emission Factors for Toxics Air Contaminants document as well as the spreadsheet of approved TAC emission factors, SBCAPCD-Approved TAC Emission Factors.xlsx, were updated;  a complete list of changes can be found in the history of updates to approved emission factors for toxic air contaminants (opens in a new tab).  More information can be found on the District’s Toxic Air Contaminant Emission Factors webpage.
• 11/12/25: The District’s Modeling Guidelines for Health Risk Assessments (APCD-15i (opens in a new tab)) was updated; see the history of updates to Form -15i (opens in a new tab).
• 2/28/25: The District’s  Modeling Protocol Tables for HRA Report were updated; see the history of updates to Modeling Protocol Tables for HRA Report.
• 11/12/24:  The District’s Meteorological Data webpage was updated with new files and a map of the site locations.
• 12/29/23:  The District’s Guidelines for Preparing Air Toxics Emission Inventory Plans and Reports (opens in a new tab) were updated; see the history of updates to ATEIP/R Guidelines.  The Modeling Protocol Tables for ATEIP were not updated at this time; the most recent version is dated August 2021.
• 12/31/20:  The Air Toxics Certification form apcd-15c.pdf was newly published; this form must be submitted with all HRAs, ATEIPs, ATEIRs, and RRAPs.

Guideline Documents

• Modeling Guidelines for Health Risk Assessments: Form-15i (opens in a new tab).  All refined health risk assessments must follow the current version of this guideline document.  Along with a health risk assessment report, the completed Modeling Protocol Tables for HRA Report must be submitted for all refined health risk assessments.
• Gasoline Station Health Risk Assessments: Form -25T (opens in a new tab).  All health risk assessments for gas stations must be accompanied by this completed form and follow the current version of the form.
• Guidelines for Preparing Air Toxics Emission Inventory Plans and Reports (opens in a new tab).  All Air Toxics Emission Inventory Plans and Reports must follow the current version of this guideline document.  The completed Modeling Protocol Tables for ATEIP (opens in a new tab) must be submitted with the Air Toxics Emission Inventory Plan.

Air Toxics Forms

• District’s Air Toxics Certification Form-15c.
• AB 2588 Quadrennial Update Form (opens in a new tab).
• District’s Quadrennial Update Summary Addendum Air Toxics Form-15u (opens in a new tab).

Air Toxics Calculations

• Prioritization Calculation Score Spreadsheet:  SBCAPCD Prioritization Calculation Spreadsheet.  Use this spreadsheet to determine stationary-source wide prioritization scores, as documented in the SBCAPCD Prioritization Guideline Document (opens in a new tab).
• SBCAPCD-Approved Emission Factors for Toxic Air Contaminants: TAC Emission Factors Spreadsheet.  Use this spreadsheet and the District’s Approved Emission Factors for Toxic Air Contaminants (opens in a new tab) to determine the appropriate emission factors and calculation methodology for various source types.
• Alternate Refined Acute Calculation Template: ARAM Calculation Spreadsheet.  Use this spreadsheet and Appendix H of the District’s Form-15i (opens in a new tab) to calculate AERMOD emission inputs for the alternate refined acute risk analysis.

Performing Health Risk Assessments

• The HARP modeling program can be obtained from CARB’s website (opens in a new tab).
• District-approved meteorological data for use in AERMOD are available on the District’s Meteorological Data (opens in a new tab) webpage.

Reference Material

• US EPA: Hazardous Air Pollutants/Unified Air Toxics WebSite (opens in a new tab).  Basic facts, pollutants and sources, technical resources.
• US EPA: Unified Air Toxics WebSite Health Effects Notebook for Hazardous Air Pollutants (opens in a new tab).  Fact sheets and additional information on effects on human health of substances that are defined as hazardous by the 1990 amendments of the Clean Air Act.
• California Air Resources Board Air Toxics Program (opens in a new tab).  Information about AB 2588, toxics monitoring data, news, ATCMs, and more.
• California Air Resources Board Consolidated Table of OEHHA/ARB Approved Risk Assessment Values (opens in a new tab).  Table of all cancer potency values and noncancer acute, 8-hour, and chronic Reference Exposure Levels (RELs) that are available for use in the AB 2588 Air Toxics “Hot Spots” Program.
• Office of Environmental Health Hazard Assessment (opens in a new tab).  OEHHA is responsible for conducting health risk assessments of chemical contaminants in air and developing risk assessment guidance.
• “Hot Spots” Fee Table and Flow Chart (opens in a new tab).  Use this link to determine a facility’s state fee.   Annual state fees are based on risk and size of the facility.  “Hot Spots” fee categories, complexities, fee amounts, and description of each risk category are shown on this link.
• California Air Toxic Emission Factors (CATEF) Search (opens in a new tab).  Use CARB’s database to search for air toxic emission factors.

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