Toxic Air Contaminant Emission Factors


The District has published approved toxic air contaminant (TAC) emission factors for various source types in the workbook SBCAPCD-Approved TAC Emission Factors.xlsx.  Additional source types will be added when approved.

The District’s Approved Emission Factors for Toxic Air Contaminants discusses the emission factors approved by the District for calculating TAC emissions for health risk assessments.  The TAC emission factor document also presents formulas to calculate both maximum hourly and average annual emissions for each equipment type.  For any method or emission factor not listed in the document, contact the District for approval.  When available, use site-specific emission factors from District-approved source tests.

A complete list of changes to the TAC emission factor workbook and document since they were originally published in August 2018 can be found in the history of updates to approved emission factors for toxic air contaminants.

Links to References

Links are provided in the District’s Approved Emission Factors for Toxic Air Contaminants for all references available online.  References not available on other websites are included below:

  • Landfill Gas Fired IC Engine:  In April 2013, Total Air Analysis, Inc. conducted source testing on a landfill gas fired internal combustion (IC) engine at Marian Medical Center.  The source test report is available here.  This engine is equipped with an oxidation catalyst and is operated by J&A Santa Maria, LLC.  This internal memorandum lists the District-approved emission factors for landfill gas fired IC engines with oxidation catalysts.
  • Landfill Gas Fired Flare:  In September 2010, Total Air Analysis, Inc. conducted source testing on a landfill gas fired flare at the Santa Maria Landfill.  The source test report is available here.  The District modified the resulting emission factors in the June 2014 spreadsheet, Landfill Gas Fired Flare Toxic Emission Factors.xls.
  • CARB’s VOC Species Profiles:  The California Air Resources Board (CARB) published the Identification of Volatile Organic Compound Species Profiles in 1991.  This document is used to determine emission factors for oil and gas fugitives.

Other Information

  • Detailed requirements on performing health risk assessments are included in the District’s Modeling Guidelines for Health Risk Assessments, Form -15i.
  • More information about air toxics is available on the District’s Air Toxics for Business webpage.