Hazardous Air Pollutants: Understanding The Strict Standards

Hazardous air pollutants (HAPs) are known to cause cancer and other serious health issues, such as reproductive problems or birth defects. HAPs also have a wide range of environmental impacts. The Clean Air Act Amendments of 1990 require the Environmental Protection Agency (EPA) to regulate HAPs, also known as air toxics, from industrial facilities in two phases. The EPA develops regulatory programs that limit emissions from stationary sources, such as major sources and area sources. The EPA also uses standards called Maximum Achievable Control Technologies (MACTs) to control and reduce HAP emissions from specific source categories.

The Clean Air Act

Section 112 of the Clean Air Act specifically addresses emissions of hazardous air pollutants. Prior to 1990, the CAA established a risk-based program with limited standards. However, the 1990 Clean Air Act Amendments strengthened the regulations by requiring the issuance of technology-based standards for major sources and certain area sources. "Major sources" refer to stationary sources that emit or have the potential to emit 10 tons per year or more of a single hazardous air pollutant or 25 tons per year or more of a combination of hazardous air pollutants. On the other hand, an "area source" is defined as any stationary source of hazardous air pollutants that is not a major source, excluding motor vehicles and non-road vehicles.

Under the Clean Air Act, the Environmental Protection Agency (EPA) is responsible for developing regulatory programs and setting National Ambient Air Quality Standards (NAAQS) to limit emissions from stationary sources. These emission standards are often referred to as "maximum achievable control technology" (MACT) standards, which mandate the highest possible reduction in hazardous air pollutant emissions. The EPA works collaboratively with state, tribal, and local air agencies to implement and enforce these standards across the country.

In summary, the Clean Air Act plays a crucial role in mitigating the harmful impacts of hazardous air pollutants on human health and the environment. Through the establishment of emission standards, collaboration with various agencies, and the delegated responsibilities of the Administrator, the Act strives to reduce air pollution and safeguard public well-being.

HAPs and their sources

Hazardous air pollutants (HAPs) are substances known or suspected to cause cancer and other serious health issues. HAPs come from a variety of sources and have a wide range of health and environmental impacts. The Clean Air Act requires the US Environmental Protection Agency (EPA) to regulate HAPs from categories of industrial facilities in two phases. The EPA has been prioritising the reduction of urban air toxics since the 1990 Clean Air Act Amendments.

The EPA uses HAP emissions and ambient monitoring data to develop regulatory programs that limit emissions from stationary sources. The term "stationary source" refers to any fixed location that emits a pollutant, such as power plants, steel mills, and factories. The term "area source" refers to any stationary source of HAPs that is not a major source, excluding motor vehicles and nonroad vehicles.

The EPA's National Air Toxics Assessment (NATA) inventory is its most recent risk modelling inventory. It is built on the National Emissions Inventory (NEI), which the EPA issues every three years and incorporates state Quality Assurance (QA) revisions. The geographic area of the NATA inventory is statewide, and it includes point sources, area sources, and mobile sources. Point sources are stationary sources that are major emitters, such as power plants, steel mills, and factories. Area sources are smaller emitters that may be dispersed over a more extensive area, such as dry cleaners or gas stations. Mobile sources include vehicles, planes, and trains.

The EPA maintains a list of 187 regulated air toxics, and IDEM's HAPs emissions inventory includes a list of the sources of these pollutants in Indiana, along with the estimated amount of pollutants emitted over a certain timeframe. The Administrator is responsible for establishing emissions standards and can make adjustments based on various factors, including the potency and persistence of the pollutant.

HAPs and health

Hazardous air pollutants (HAPs) are known to cause cancer and other serious health issues. HAPs have a wide range of health effects and environmental impacts. The Clean Air Act requires the Environmental Protection Agency (EPA) to regulate HAPs, also known as air toxics, from categories of industrial facilities in two phases. The EPA uses HAP emissions and ambient monitoring data to develop regulatory programs that limit emissions from stationary sources.

The Administrator is responsible for establishing emission standards and publishing a list of major and area sources of HAPs, which are regularly revised based on public comments and new information. The term "area source" refers to any stationary source of HAPs that is not considered a major source, excluding motor vehicles and nonroad vehicles regulated under Subchapter II. The Administrator has the authority to determine and adjust emission limitations for specific sources on a case-by-case basis.

When establishing emissions standards, the Administrator must consider various factors, including the potency, persistence, and potential for bioaccumulation of the pollutant, as well as health studies and risks associated with background concentrations of HAPs. The goal is to protect public health and prevent adverse environmental effects while also taking into account costs, energy, and safety considerations.

The Administrator also has the power to delete certain chemical substances containing listed HAPs that meet specific deletion requirements. Additionally, the Administrator can establish separate subcategories for certain industries, such as boat manufacturing for styrene emissions, if deemed appropriate. Overall, the regulatory process aims to balance the reduction of HAPs with other relevant factors to ensure the protection of public health and the environment.

HAPs and the environment

Hazardous air pollutants (HAPs) are harmful to human health and the environment. HAPs are known to cause cancer and other serious health issues. They can also have adverse effects on wildlife, such as decreased growth and reproductive rates in plants and animals, and neurological impacts on vertebrates. These pollutants include carcinogens, mutagens, and teratogens, and can come from a variety of sources, including industrial facilities and motor vehicles.

The Clean Air Act (CAA) and the National Environmental Policy Act (NEPA) play a crucial role in regulating and addressing HAPs. The CAA sets forth Maximum Achievable Control Technology (MACT) Standards and the National Emissions Standards for Hazardous Air Pollutants (NESHAP) to guide rule-making and enforcement. MACT Standards focus on major sources emitting or potentially emitting 10 tons per year of HAPs. The "MACT floor" is the minimum standard that industries must meet for compliance. NESHAP, on the other hand, provides comprehensive standards for addressing hazardous air pollutants.

The Environmental Protection Agency (EPA) is responsible for enforcing these standards and has been working to reduce emissions of urban air toxics since the 1990 CAA Amendments. The EPA uses HAP emissions and ambient monitoring data to develop regulatory programs that specifically target stationary sources of pollution. The EPA also has the authority to establish emission standards for new sources, which are stationary sources that commence construction or reconstruction after the proposal of relevant regulations.

Additionally, the EPA is tasked with regularly publishing and revising a list of major and area sources of HAPs. Area sources refer to stationary sources of hazardous air pollutants that are not considered major sources, and they exclude motor vehicles and nonroad vehicles regulated under Subchapter II. The EPA can establish different criteria for radionuclides and may set lesser quantity thresholds for major sources based on factors such as pollutant potency, persistence, and potential for bioaccumulation.

HAPs and permits

Hazardous air pollutants (HAPs) are those known to cause cancer and other serious health issues. The Clean Air Act requires the US Environmental Protection Agency (EPA) to regulate emissions of HAPs that are hazardous to human health or the environment.

There are two types of federal air regulations: the National Emission Standards for Hazardous Air Pollutants (NESHAPs) and New Source Performance Standards (NSPSs). NESHAPs are federal air regulations that apply to two types of facilities: major sources and area sources. Major sources have the potential to emit more than 10 tons per year of a single HAP or 25 tons per year of any combination of HAPs. Area sources are not major sources and have the potential to emit less than 10 tons per year of a single HAP or 25 tons per year of any combination of HAPs. Many small businesses fall into the category of area sources.

NSPSs can determine whether a facility needs an air permit. If an NSPS applies to a facility, an air permit may be required regardless of whether the facility's potential to emit exceeds air permit thresholds. The EPA uses standards called Maximum Achievable Control Technologies (MACTs) to control and reduce HAP emissions from specific source categories. MACTs cover both major and area sources.

Companies intending to build or modify facilities that emit pollutants into the air must determine if they need to apply for an air quality permit or submit a notice of intent to the relevant state authority before construction. The state authority will then issue permits and review notices of intent to ensure state and federal emissions requirements are met, and public health and the environment are protected. To determine if a permit is required, emissions from the facility are calculated as if the facility were operating continuously, 8,760 hours per year (24 hours/day, 365 days/year). These emissions are then compared to the thresholds in the regulations to determine the required permit type and whether the facility will be designated as a minor or major source.

Prevention of Significant Deterioration (PSD) Construction Permits are required for PSD Major Stationary Sources in areas designated as attainment or unclassifiable for a national or state ambient air quality standard. A PSD permit must be obtained before the facility is constructed or modified. Title V Operating Permits are required for major sources. These permits are issued 12 months after the facility starts operating.

Frequently asked questions