"Hot Spots" Inventory Guidelines

This page last updated May 29, 2020

The AB 2588 Air Toxics "Hot Spots" Emission Inventory Criteria and Guidelines Regulation (Guidelines, or EICG Regulation) provides direction and criteria to facilities on how to compile and submit air toxics emission data required by the "Hot Spots" Program.   The current regulation was approved by the Office of Administrative Law on August 27, 2007.

Webinar to Discuss Proposed Amendments to the EICG Regulation 

The California Air Resources Board (CARB) held a webinar on April 30, 2020, to discuss proposed amendments to the EICG Regulation. These proposed amendments are necessary to ensure comprehensive and up-to-date reporting of emission inventories and subsequent evaluation of health risks. The proposed amendments are also designed to support community-focused efforts at CARB to reduce criteria pollutant and air toxic emissions from California’s most disadvantaged communities. We invite you to join us and provide your feedback during the webinar at the date and time below.

DATE:  April 30, 2020 (see below for recording and materials)

Webinar Materials
  • Additional Supporting Documents 
    1. Appendix A: Proposed List of Substances to be Reported (workshop draft)
    2. Appendix C: Examples of Chemicals Expected by Process and/or Industry Sectors (workshop draft)
    3. Appendix E: Proposed Requirements for Smaller Facilities (workshop draft)
    4. Scientific Review Panel: Interim Findings Regarding the Chemical List

For questions about the webinar, please contact:
Anne Klein, Air Pollution Specialist or
Gabe Ruiz, Manager, Toxics Inventory and Special Projects Section

Subscribe to GovDelivery for Air Toxics "Hot Spots" Criteria and Guidelines notifications

Scientific Review Panel Evaluation

As part of our preparations for amending the current regulation, CARB staff solicited support from the Scientific Review Panel (SRP) in evaluating the proposed updates to the chemical substances list in Appendix A of the regulation. The following documents were provided to the SRP for their review:

SRP Chemical List Introduction.pdf ‐ Transmittal document requesting SRP review of the proposed updates.
Existing Appendix A.pdf ‐ A list of the substances in Appendices A‐I to A‐III of the current regulation.
Master List of New Proposed Substances.pdf ‐ A list of over 800 new substances proposed for addition to Appendices A-I to A-III, along with a list of over 500 substances that were evaluated but are not being proposed for inclusion.
New Proposed Appendix A‐I by Category.pdf This is the subset of the Master List: new substances proposed for addition to Appendix A‐I, grouped into the following eight categories:
a) Carcinogens
b) Developmental and Reproductive Toxicants
c) Pesticides
d) Metals
e) Other Inorganics
f) Pharmaceuticals
g) Neurotoxins
h) Other

Master List of New Proposed Substances.xlsx
‐ An Excel version of the Master List of new substances proposed for addition, separated into tabs for Appendices A‐I, A‐II, A‐III, and substances that were evaluated but are not being proposed for inclusion.

Current Regulation (approved by OAL on August 27, 2007)

Regulation (CCR) (pdf - 42k)
Emission Inventory Criteria and Guidelines Report (Sections I-XI) ( doc - 325k ) ( pdf - 325k )
Appendix A (List of Substances) ( Excel - 178k ) ( A-I pdf - 115k ) ( A-II pdf - 64k ) ( A-III pdf - 55k ) (Notes pdf - 64k )
Appendix BI (Reporting Formats) ( doc - 104k ) ( pdf - 104k )
Appendix BII (Reporting Forms) ( doc - 1,913k ) ( pdf - 1,913k )
Appendix C (Facility Responsibilities) ( doc - 195k ) ( pdf - 195k )
Appendix D (Source Testing) ( doc - 91k ) ( pdf - 91k )
Appendix E (Requirements for Smaller Facilities) ( doc - 75k ) ( pdf - 75k )
Appendix F (Screening HRAs) ( doc - 57k ) ( pdf - 57k )
Appendix G (Documents Incorporated by Reference) ( doc - 55k ) ( pdf - 55k )

Formal Rulemaking Documents

The Emission Inventory Criteria and Guidelines are used for preparing emission inventory plans and reports to develop site-specific inventories of air emissions of toxic substances. The Guidelines do the following:  1) specify which facilities are subject to air toxics emission inventory reporting and update reporting; 2) specify information a facility operator must include in a facility's air toxics emission inventory plan and inventory report; 3) identify specific classes of facilities that emit less than ten tons per year of criteria pollutants that are subject to the Hot Spots program and specify their emission inventory reporting requirements; 4) specify source testing requirements, acceptable emission estimation methods, and the reporting formats to be used; 5) establish groups of the substances to be inventoried; 6) designate facilities into levels for purposes of update reporting, based on prioritization scores, risk assessment results, or de minimis thresholds; 7) exempt "low level" facilities from further update reporting unless specified reinstatement criteria are met, and specify the update reporting requirements for other facilities; 8) specify information a facility operator must include in a facility's update to the facility emission inventory; and 9) include provisions for integrating Hot Spots reporting with other district programs if specified criteria are met.

The Guidelines are organized into sections which address related requirements.  Sections are included on applicability, facility removal from the program, update categories, reporting requirements, and source testing requirements.

The appendices to the Guidelines are useful documents which may be downloaded separately from the Guidelines Report. Appendix A includes three lists of substances in the program: those for which emissions must be quantified; those for which production, use, or other processes must be reported; and those which need not be reported unless manufactured by the facility. Appendix B contains reporting formats and instructions.  Appendix C is the Facility Guideline Index which specifies responsibilities for specific facility classes. Appendix D indicates source testing requirements.   Appendix E specifies requirements for classes of facilities emitting less than 10 tons per year of criteria pollutants.  Appendix F contains the criteria for inputs for risk assessment using screening air dispersion modeling. Appendix G is the list of documents which have been incorporated into the Guidelines by reference.

Link to previous drafts of Guidelines Regulation

Frequently Asked Questions (FAQs) (doc) (pdf) (as of 9/07)

ARB's Emission Factor Certification Database
1989 Technical Guidance Document for EI Guidelines (PDF - 8MB)
  Addendum to TGD for wood fired boilers
More Information about Appendix A - List of Substances