California Air Resources Board

This page is an archive of the previous version of the AB 2588 "Hot Spots" Guidelines Regulation. For the most recent Guidelines, visit "Hot Spots" Inventory Guidelines.

The Previous version of the Guidelines (Adopted by Air Resources Board on July 25, 1996; Effective July 1, 1997 through September 25, 2007)

• Regulation (CCR)
• Emission Inventory Criteria and Guidelines Report (Without Appendices)
• Appendix A: List of Substances | Excel
• Appendix B: Reporting Format and Instructions
• Appendix C: Facility Guideline Index
• Appendix D: Source Testing: Summary of Requirements
• Appendix E: Requirements for Facilities Emitting <10 tpy of Criteria Pollutants
• Appendix F: Criteria for Screening Risk Assessment
• Appendix G: List of Documents Incorporated by Reference

The AB 2588 "Hot Spots" fee categories, complexities, fee amounts, and description of each risk category are shown below. State fees are risk-based and assessed on an annual basis. The size of the facility (complexity) also affects the fee amounts in each risk category with larger (complex) facilities paying a higher amount than smaller (simple) facilities.

"Hot Spots" Facility Fee Category Flowchart

Use the following flow chart to determine the appropriate fee category for a given facility.

The California Toxics Inventory (CTI) currently provides emissions estimates by stationary (point and aggregated point), areawide, onroad mobile (gasoline and diesel), offroad mobile (gasoline, diesel, and other), and natural sources.

The CTI is developed by speciating ARB estimates of Total Organic Gas (TOG) and Particulate Matter (PM) for area, mobile, and natural sources using the most recent speciation profiles. Speciated emissions for each source category are then reconciled with reported stationary point source toxics data to establish a complete inventory.

Stationary sources include point sources provided by facility operators and/or districts pursuant to the Air Toxics “Hot Spots” Program (AB 2588), and aggregated point sources estimated by the ARB and/or districts. Areawide sources are those that do not have specific locations and are spread out over large areas such as consumer products and unpaved roads. Mobile sources consist of onroad vehicles such as passenger cars and trucks, motorcycles, busses, and heavy-duty trucks. Offroad sources include trains, ships, and boats. Natural sources like wildfires are also included.

Draft 2010 CTI Summary Table (November 2013) (Excel)

2008 CTI Summary Table - released on December 10, 2008 (Excel)

2006 CTI Summary Table - released on May 20, 2008 (Excel) (PDF)

2004 CTI Summary Table (Excel) (PDF)

Documentation (PDF)

Assembly Bill (AB) 2588 (Connelly), the Air Toxics "Hot Spots" Information and Assessment Act, requires facilities that are ranked as a high priority (see Prioritization) to submit a health risk assessment (HRA) to the air pollution control and air quality management districts (district). A risk assessment, as defined under the Air Toxics "Hot Spots" Act, includes a comprehensive analysis of the dispersion of hazardous substances into the environment, the potential for human exposure, and a quantitative assessment of both individual and population-wide health risks associated with those levels of exposure. The risk assessments submitted by the facilities are reviewed by the Office of Environmental Health Hazard Assessment (OEHHA) and approved by the district. In addition, the district may require facilities in the intermediate and low priority categories to also submit a health risk assessment.

OEHHA HRA Guidelines

Senate Bill 1731, which amends the "Hot Spots" Program, requires OEHHA to adopt risk assessment guidelines for the program using a full public review process. You can obtain a copy from OEHHA.

Hotspots Analysis and Reporting Program

The Hotspots Analysis and Reporting Program (HARP) is a software suite that addresses the programmatic requirements of the AB 2588 Air Toxics "Hot Spots" Program.  HARP incorporates the information presented in the 2015 Air Toxics Hotspots Program Guidance Manual for Preparation of Health Risk Assessments. HARP is divided into three programs: the Emissions Inventory Module (EIM), Air Dispersion Modeling and Risk Tool (ADMRT), and Risk Assessment Standalone Tool (RAST). HARP can be used by the air pollution control and air quality management districts (districts), facility operators and other organizations or individuals to promote statewide consistency, efficiency and cost-effective development of facility emission inventories and conducting health risk assessments. HARP can also be used for conducting health risk assessments used in other programs (e.g., facility permitting, CEQA reviews).

Risk Management Policy for Risk Assessment Using the Inhalation Pathway

This policy is presented in Appendix D of the document CARB/CAPCOA Risk Management Guidance for Stationary Sources of Air Toxics (July 23, 2015). CARB and CAPCOA established this policy through a public process with input from industry and environmental representatives. This policy uses the new risk assessment science included in the Office of Environmental Health Hazard Assessment (OEHHA) Guidance Manual (OEHHA Manual) while providing a reasonable estimate of potential cancer risk for use in risk assessments for risk management decisions. The individual Districts have the authority to decide how, or if, they will use this recommended policy in their programs. 

Consolidated Table of OEHHA/CARB Approved Risk Assessment Health Values

The Consolidated Table of OEHHA / CARB Approved Risk Assessment Health Values is a quick look-up 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. The most current health values should be used for the development of a facility health risk assessment. For more information on the OEHHA Guidelines, see the OEHHA website. Users of this table are advised to monitor the OEHHA website for any updates to the health values. 

Review of Updated and Screening HRAs

In 1997, the staff of CARB, the OEHHA, and the districts collaborated to develop a streamlined process for the submittal and review of updated, and screening, health risk assessments (HRAs). That joint effort resulted in the development of a set of forms (see HRA forms Word | PDF) intended to accompany the submittal of updated, or screening, HRAs to the appropriate district and to OEHHA. There is also a list of the minimum data fields required when submitting an updated, or screening, HRA for those individuals that chose to not use the forms developed.

Industrywide Risk Assessments

CAPCOA, in cooperation with OEHHA and CARB, are developing three industrywide risk assessment procedures. The purpose of these industry specific assessments is to assist both the districts and facilities with the emission inventory and risk assessment requirements of the "Hot Spots" program (see Overview of "Hot Spots" Program).

Facilities which meet a specific set of requirements outlined in the law are candidates for an industrywide assessment. The requirements are focused on small businesses that are from the same industrial class, where individual compliance would impose severe economic hardships, and where emissions are easily and generically characterized.

Please refer to the Industrywide Risk Assessment List below to download a copy of a particular risk assessment or to get in contact with CARB or district staff person responsible for that guideline. 

Industrywide Risk Assessment Guidelines

Overview of the Air Toxics "Hot Spots" Act
"Hot Spots" Powerpoint Slide Presentation (Fall 2002)
"Hot Spots" Powerpoint Slide Presentation (2005)

AB 2588 -- Air Toxics "Hot Spots" Information and Assessment Act of 1987

Health and Safety Code:

1. H&S section 44340 - requires an inventory plan by August 1, 1989; and Section II.E. of the EIC&G Regulation (93300.5, title 17 CCR) - requires an inventory plan by August if requested by the district before January of that year.
2. H&S section 44340 (b) - requires the district to approve the inventory plan within 120 days.
3. H&S section 44341 - requires facility to submit an inventory report within 180 days.
4. H&S section 44343 - requires district to approve the inventory report within 90 days.
5. H&S section 44360(a) - requires the district to prioritize the facility within 90 days.
6. H&S section 44360(b) - requires facility to complete HRA within 150 days.
7. H&S section 44361 - requires OEHHA to review HRA within 180 days.
8. H&S section 44362(a) - requires district to review HRA within 1 year.
9. H&S section 44362(b) - requires facility to conduct public notification.
10. H&S section 44391(f) - requires facility to submit a risk reduction audit and plan within 6 months.
11. H&S section 44391(g) - requires the district to review the plan within 3 months; and H&S section 44391(a) and (c) - requires risk to be reduced within 5 years with option of an additional 5 years.

This page documents the ARB's efforts to QA the CEIDARS toxics data.

1. QA of Toxics Data
   As part of our emission inventory data review, ARB staff has identified several facilities with toxic emissions in our CEIDARS inventory that we would like district staff to review for accuracy. This list was compiled in part by identifying the highest prioritization (potency-weighted) scores for each toxic in our point source inventory. We also identified several facilities that emit significantly more of a listed toxic than any other facility in California. Please confirm the accuracy of the emissions data if possible, and let us know if there are any problems with the data.
   
   Download the short list of facilities for district review (80k) 
   
   Background Information:
   Top potency-weighted emissions
   Top toxics emissions (by mass)

2. Deleted Pollutants
   The following pollutants have been removed from the CEIDARS Pollutant Table:

   We used to use these POLs...		Now we use these POLs.
   Old POL (No longer in CEIDARS)	POLN (of Old POL)	Correct POL (in CEIDARS)	POLN (of Correct POL)
   1015	[D] Arsenic compounds (inorganic)	1016	Arsenic compounds (inorganic)
   1021	[D] Beryllium compounds	7440417	Beryllium
   1045	[D] Cadmium compounds	7440439	Cadmium
   1067	[D] Copper compounds	7440508	Copper
   1105	[D] Fluorocarbons (chlorinated and brominated)	1104	Fluorocarbons (chlorinated)
   1120	[D] Hexachlorocyclohexanes	608731	Hexachlorocyclohexanes
   1130	[D] Lead compounds (Inorganic)	1128	Lead compounds (inorganic)
   1132	[D] Manganese compounds	7439965	Manganese
   1133	[D] Mercury compounds	7439976	Mercury
   1145	[D] Nickel compounds	7440020	Nickel
   1170	[D] Selenium compounds	7782492	Selenium
   1204	[D] Toluene diisocyanates	26471625	Toluene diisocyanates
   1210	Xylenes	1330207	Xylenes (mixed)
   1211	[D] Zinc compounds	7440666	Zinc
   3333393	[D] Nickel carbonate	3333673	Nickel Carbonate
   124403	[D] Dimethylamine	dropped from CEIDARS
   1040	[D] Bromine Compounds (inorganic)	dropped from CEIDARS

   
   [D] Acetone will be retained in CEIDARS.
    
3. Missing Criteria and Toxics Emissions
   Most facilities in CEIDARS have both criteria and toxic emissions. However, some large (>10tpy) criteria pollutant facilities do not have corresponding toxics data, and some facilities with large (>10tpy) toxics do not have corresponding criteria pollutant data. Each of these lists is linked below. [Note: Some facilities are exempt from reporting toxics because their risk assessment is less than 1 per million. The HRA score for these facilities must be reported in CEIDARS.]
   Facilities with No Emissions
   Criteria Pollutant Facilities Missing Toxics Data
   Toxics Facilities Missing Criteria Pollutants
    
4. Hexavalent Chromium Emissions
   Highest Hex Chrome Sources for 2004-2006
    
5. FEE_CAT
   The Fee_Cat Code in the Facility Table indicates the status of the facility (low, medium, or high risk) using letter codes A-G, with a few additional codes for exempt facilities. Fee_Cat codes are being corrected, based on AB 2588 State Fee information.
    
6. Diesel in CEIDARS
   Diesel emissions should be reported using toxics emittent ID# 9901, and using criteria pollutant PM10 with appropriate SCC Codes. When the criteria and toxic emissions are not equal, it is difficult for ARB to determine which emissions are correct. Our analysis is here: Diesel
    
7. Chrome Platers
   ARB has compiled updated emission estimates for chrome platers. ARB staff is reconciling the data for South Coast, which includes more than 75% of all chrome platers in CA. Chrome Platers in SCAQMD
    
8. Comparison by SIC, POL, and SCC
   ARB compared the number of different SIC Codes, Pollutants, and SCC Codes in CEIDARS from 2001 through 2004 to identify trends in the toxics data. The data clearly shows that districts are submitting more data on gasoline service stations; more sources are reporting benzene and formaldehyde emissions (primarily from South Coast's AER); and more diesel engines are being reported, along with a higher percentage of generic classifications for some processes (SCC Codes). More information is here: by SIC - by Pollutant -- by SCC (Top20)
    
9. Comparison with TRI data
   All of the top emitters in the U.S. EPA's TRI 2005 Facility Inventory reported criteria pollutants in the 2004 CEIDARS Inventory. Some toxics data appears to be inconsistent. TRI data
    
10. Location Data
    ARB staff is verifying location data of facilities in CEIDARS, with an emphasis on large emission sources, including facilities in CHAPIS (Community Health Air Pollution Information System). New procedures are in place to automate this process each year. Some facility locations may need to be verified by districts. More information will be provided here soon.
     
11. Potency-weighted Toxics
    A Rank-Ordered List of Toxics has been compiled, which shows the highest potency-weighted scores for 1996, 2001, 2004, 2005, and 2006.
     
12. Air Toxics Inventory of all sources (Point, Areawide, On-Road Mobile, Off-Road Mobile, and Natural)
    (Draft -- double counting not yet addressed)
     
13. Emissions comparison between 2001 and 2005 emissions data.
     
14. Linking all prioritization scores and risk data with all CEIDARS facilities.
    ARB is considering asking districts to provide prioritization scores for all facilities in CEIDARS so we can better track facilities... Right now we only have prioritization scores for facilities that pay State fees. This includes new facilities with a high prioritization score (but no HRA), and facilities with an HRA >1 per million. The data will be reflected in CEIDARS as either a high priority, or not high-priority facility (the score won't actually be visible).

Speciation profiles provide estimates of the chemical composition of emissions, and are used in the emission inventory and air quality models. CARB maintains and updates estimates of the chemical composition and size fractions of particulate matter (PM) and the chemical composition and reactive fractions of total organic gases (TOG), for a variety of emission source categories.

Speciation Profiles

CARB's current PM and Organic Gas Speciation Profiles are available for download from this page as Excel spreadsheet files (PMPROF and ORGPROF). Each speciation profile provides weight fraction data of each chemical species making up the total particulate matter or total organic gases, and is designated by an identification code number. The chemical species are identified by a 5-digit SAROAD code and the chemical name. For PM, there are also PM size fraction tables, which provide the particulate mass within each size fraction (PM total, PM 10, or PM 2.5) for individual source categories. The PMSIZE spreadsheet file contains a summary of the PM size fractions for each PM profile. To compute the amount of a specific chemical constituent in the PM size fraction of interest, each PM chemical weight fraction must be multiplied by the appropriate PM size fraction.

Diesel particulate matter (DPM) is identified through the classification of specific Source Classification Codes (SCCs) or Emission Inventory Codes (EICs) associated with diesel particulate emissions. A complete list of SCCs and EICs linked to DPM is maintained and regularly updated by CARB staff, in coordination with OEHHA and other external partners. 

Download Option

CHEM- Chemical species data for source categories

FRAC - Fraction data for source categories

ORGPROF - Organic chemical profiles for source categories

PMPROF - Particulate matter chemical profiles for source categories

PMSIZE - Particle size fraction data for source categories

ORGPROF_REF - Reference number for organic gas profiles (link to the references)

PMPROF_REF - Reference number for PM profiles (link to the references)

DPM - List of categories linked to DPM

• DIESELPM_202405220754

EICG Amendments: Workshop and Rulemaking Comments Received

Comments received as part of CARB's 2020 rulemaking process to develop amendments to the AB 2588 Air Toxics "Hot Spots" Emission Inventory Criteria and Guidelines Regulation (Guidelines, or EICG Regulation).

Webinar Comments & Questions Submitted

• April 30, 2020: EICG Webinar on Proposed Amendments
• September 30, 2020: EICG-CTR Joint Webinar on Proposed Amendments
• February 11, 2021: EICG-CTR Joint Webinar on Proposed 15-Day Modifications

Informal Comments* Submitted Following the Webinar held April 30, 2020 and the Posting of Draft Materials on July, 29 2020

* Informal comments are not included or submitted as part of the formal rulemaking docket for the regulation, but are considered and evaluated in developing the proposed amendments to the regulation.