The District’s air toxics program implements state and federal regulations regarding air toxics from stationary sources of air pollution. These rules are described below.
California rules refer to air toxics as “toxic air contaminants,” or TACs, and identify over 700 chemicals as TACs.
The District implements and enforces California’s Toxic Air Contaminant Identification and Control Act (AB 1807, passed in 1983), which created California’s program to reduce exposure to air toxics. Under this legislation, the California Air Resources Board (CARB) issues Airborne Toxic Control Measures (ATCMs). For more information on ATCMs, see the District’s ATCM webpage and CARB’s Airborne Toxic Control Measures webpage.
The District also implements and enforces the California Air Toxics “Hot Spots” Information and Assessment Act (AB 2588, passed in 1987 and amended in 1992).
The main goals of the Hot Spots Act are to:
- Identify the amount of air toxics emitted into the air by businesses
- Estimate potential health risk for members of the public exposed to these air toxics
- Inform individuals exposed to significant health risk of the air toxic emissions and their associated health risk
- Protect the public health by reducing air toxic emissions from businesses to acceptable levels
The District tracks toxic air emissions from stationary sources, and also develops “industry-wide” toxic emission inventories for smaller stationary sources, such as dry cleaners and gasoline stations. Over time, the District has worked with businesses through the Hot Spots program to reduce risk from air toxics. Since 1991, the number of significant risk facilities in Santa Barbara County has been reduced by 100 percent. In 1991 there were 51 significant risk facilities and now there are zero. For more information, see Significant Risk Facilities.
In addition to evaluating existing facilities in AB 2588, the District evaluates health risk associated with new or modified facilities during the permit process when issuing new Authority to Construct permits. The goal for the District’s new source review health risk program is to prevent a new or modified facility from creating a significant risk to the community (using the significance criteria established by the AB 2588 program). With this program, no additional significant risk facilities have been created since 1991.
The Office of Environmental Health Hazard Assessment (OEHHA) developed the Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments for use in implementing the Air Toxics Hot Spots Program; more details about this Guidance Manual can be found in the section below.
For more information on the California Air Toxics “Hot Spots” Information and Assessment Act see the District’s AB 2588 Air Toxics “Hot Spots” Program webpage or CARB’s AB 2588 Air Toxics “Hot Spots” webpage.
Revisions to OEHHA Guidance Manual
Due to growing concerns regarding children’s increased susceptibility to environmental contaminants, the California Legislature passed the Children’s Environmental Health Protection Act in 1999 (SB 25). SB 25 requires explicit consideration of infants and children in assessing health risks from air toxics. In response to SB 25, OEHHA re-assessed their methods and found that infants and children were not adequately protected by the existing health risk assessment methodology established in 2003. As a result, OEHHA released a revised Guidance Manual in 2015 to more explicitly consider and protect the health risk to infants and children, and to provide additional protection to other age groups.
In addition, the 2015 Guidance Manual reflects advances in the field of health risk assessments. Specifically: the cancer risk calculation was revised to account for sensitivity at early ages; the calculations were revised to account for higher exposure at younger ages; and the atmospheric dispersion model was changed to the American Meteorological Society / Environmental Protection Agency Regulatory Model (AERMOD), the EPA preferred regulatory model.
With all of these changes, the 2015 Guidance Manual methodology may result in increased cancer risk results as compared to the existing 2003 health risk assessment methodology. For more information on the revisions to the Guidance Manual, see OEHHA’s presentation and Air Toxics Hot Spots Program Guidance Manual webpage.
The federal Clean Air Act, as amended in 1990, refers to air toxics as “hazardous air pollutants,” or HAPs. The Act lists 188 HAPs and establishes Maximum Achievable Control Technology (MACT) standards for control of these chemicals. State and local agencies, such as the District, are responsible for implementing and enforcing the MACT standards, which require the use of control technologies to achieve emission reductions in industries that are major sources of HAPs (such as the aerospace or oil and gas industries), as well as in facilities that are area sources of HAPs (such as dry cleaners). The District’s program to enforce the federal provisions, commonly known as Title III, is not as fully developed as its toxics “Hot Spots” program, but will be a focus in the future.
The federal New Source Review (NSR) permitting program was passed in 1977 as an amendment to the Clean Air Act. This program program evaluates health risk associated with new or modified facilities.
National Emission Standards for Hazardous Air Pollutants (NESHAP) were first passed in 1990 as an amendment to the Clean Air Act. NESHAPs are stationary source standards for hazardous air pollutants. See the District’s Paint Stripping webpage for more information about a NESHAP that is currently in effect.
For more information on NESHAPs, see the USEPA’s National Emission Standards for Hazardous Air Pollutants.