What is the Air Toxic "Hot Spots" Act?

California enacted The Air Toxics "Hot Spots" Information and Assessment Act in 1987. The Act establishes a formal air toxics emission inventory risk quantification program, which is managed by California air districts.

The program goals include:

• collection of data on the emission of toxic air contaminants
• identification of facilities having localized impacts
• health risk assessment
• public notification on health risks
• reduction of the risks of "significant-risk facilities" below the level of significance

The program has been a motivating factor for facility owners to voluntarily reduce their facility's toxic emissions

 Obtain the District's most recent Air Toxics "Hot Spots" report below.

What Does the Act Require?

• facilities to report of types and quantities of certain toxic substances routinely or predictably emitted;
• air districts to determine whether or not a health risk assessment (HRA) must be conducted for the facility;
• that HRAs be conducted according to methods developed by the Office of Environmental Health Hazard Assessment (OEHHA);
• that the public be notified of significant risks posed by nearby facilities, and;
• facilities posing significant risks to prepare and implement risk reduction audits and plans within 6 months of the determination.

What is the Air Toxics "Hot Spots" Process?

The California Air Resources Board (CARB) compiles and maintains a list of substances posing chronic or acute health threats when present in the air. The Act identifies by reference over 600 substances, which are subject to the program.

A facility is subject to the Act if it:

1. manufactures, formulates, uses, or releases a substance subject to the Act (or another substance, which reacts to form such a substance) and emits 10 tons or more per year of total organic gases, particulate matter, nitrogen oxides or sulfur oxides, or;
2. is listed in any district's existing toxics use or toxics air emission survey, inventory or report released or compiled by a district, or;
3. manufactures, formulates, uses, or releases a substance subject to the Act (or substance, which reacts to form such a substance) and emits less than 10 tons per year of criteria pollutants and is subject to emission inventory requirements.

 Emission Inventory Plans and Reports:

Facilities meeting the applicability criteria must prepare air toxics emission inventory plans and emission inventory reports. CARB's Emission Inventory Criteria and Guidelines provide assistance in preparing these documents.

Risk Assessment:

After reviewing emission inventory data, the Northern Sierra Air District must rank facilities for purposes of risk assessment into high, intermediate, and low priority categories. Facilities will be re-prioritized if their inventory update shows any significant changes.

The Northern Sierra Air District priority categories consider potency, toxicity, quantity, and volume of hazardous materials released, and a facility's proximity to potential receptors. Additional information on prioritization along with guideline documentation can be found at http://www.arb.ca.gov/ab2588/prioritization.htm

Within 150 days of designation, high priority facilities and other facilities identified by the Northern Sierra Air District must prepare and submit a health risk assessment (HRA) to the Northern Sierra Air District. The HRA includes a comprehensive analysis of the dispersion of hazardous substances, the potential for human exposure, and a quantitative assessment of both individual and population wide health risks. OEHHA's Air Toxics Hot Spots Program Guidance Manual for Preparation of Health Risk Assessments supersedes previously published risk assessment methods.

Public Notification:

Once the HRA is reviewed by OEHHA and approved by the Northern Sierra Air District, the facility must notify all exposed persons of the risk assessment results if the Northern Sierra Air District determines that there is a potentially significant health risk.

ARB provides general and specific data on toxics at http://www.arb.ca.gov/toxics/cti/cti.htm. ARB also provides facility inventory data at http://www.arb.ca.gov/app/emsinv/facinfo/facinfo.php. More up to date data may be available from the Northern SierraAir District depending upon the facility's reporting cycle.