Hazardous air pollutant

National Emission Standards for Hazardous Air Pollutants (NESITAP)... 

Receptors. The receptor can be a person, animal, plant, material, or ecosystem. The criteria and hazardous air pollutants were so designated because, at sufficient concentrations, they can cause adverse health effects to human receptors. Some of the criteria pollutants also cause damage to plant receptors. An Air QuaUty Criteria Document (12) exists for each criteria pollutant and these documents summarize the most current Hterature concerning the effects of criteria pollutants on human health, animals, vegetation, and materials. The receptors which have generated much concern regarding acid deposition are certain aquatic and forest ecosystems, and there is also some concern that acid deposition adversely affects some materials. 

Table 6. Substances Listed as Hazardous Air Pollutants as Defined by the 1990 Clean Air Act Amendments...

The 1990 Clean Air Act Amendments Hst 189 hazardous air pollutants (HAPs) that the EPA must regulate to enforce maximum achievable control technology (MACT) to standards which are to be set by the year 2000. The 33/50 project calls for reduction of emissions of 17 specified solvents to predetermined levels by 1995. The SARA statute provides a mechanism by which the community can be informed of the existence, quantities, and releases of toxic chemicals, and requires that anyone releasing specific toxic chemicals above a threshold level to annually submit a toxic chemical release form to the EPA. The status of various ketones under these regulations is shown in Table 4. 

Code ofFederalKegulations, Tide 40, Section 63.185, List of Volatile Hazardous Air Pollutants, Washington, D.C., 1990. 

Hazardous Air Pollutants. Tide 3 of the CAAA of 1990 addresses the release of hazardous air poUutants (HAPs) by requiring both the identification of major stationary sources and area source categories for 189 toxic chemicals and the promulgation of control standards. Major sources of air toxics, also referred to as HAPs, include any stationary source or group of sources emitting 10 or more tons/yr of any single Hsted toxic chemical or 25 tons/yr of a combination of any Hsted toxic. Area sources of HAPs include smaller plants that emit less than the 10 or 20 tons/yr thresholds. The major sources of HAPs are typically industrial faciHties. However, Tide 3 requites the EPA to study potential health affects associated with emissions of HAPs from electric UtiHty boilers (11). 

Poly(vinyl chloride) is Hsted on the TSCA inventory and the Canadian Domestic Substances List (DSL) as ethene, chloro-, homopolymer [9002-86-2]. Because polymers do not appear on the European Community Commercial Chemical Substances listing or EINECS, poly(vinyl chloride) is listed through its monomer, vinyl chloride [75-01-4]. In the United States, poly(vinyl chloride) is an EPA hazardous air pollutant under the Clean Air Act Section 112 (40 CER 61) and is covered under the New Jersey Community Right-to-Know Survey N.J. Environmental Hazardous Substances (EHS) List as "chloroethylene, polymer" with a reporting threshold of 225 kg (500 lb). 

The total emissions of hazardous air pollutants from a CGCC plant having wet cleanup are expected to be at least an order of magnitude lower than those achievable from a modem coal-fired steam plant (41). Metals removal in hot-gas cleanup systems is still under development. 

HAPS Hazardous air pollutants TGNMO Total gas nonmethane organics... 

Finally, Sec. 112 of the Clean Air Act required that EPA pronml-gate National Emission Standards for Hazardous Air Pollutants (NESHAPs). Between 1970 and 1989, standards were promulgated for asbestos, beiylhum, mercuiy, vinyl chloride, benzene, arsenic, radionuclides, and coke-oven emissions. 

Unbumed Hydrocarbons Various unburned hydrocarbon species may be emitted from hydrocarbon flames. In general, there are two classes of unburned hydrocarbons (1) small molecules that are the intermediate products of combustion (for example, formaldehyde) and (2) larger molecules that are formed by pyro-synthesis in hot, fuel-rich zones within flames, e.g., benzene, toluene, xylene, and various polycyclic aromatic hydrocarbons (PAHs). Many of these species are listed as Hazardous Air Pollutants (HAPs) in Title III of the Clean Air Act Amendment of 1990 and are therefore of particular concern. In a well-adjusted combustion system, emission or HAPs is extremely low (typically, parts per trillion to parts per billion). However, emission of certain HAPs may be of concern in poorly designed or maladjusted systems. 

Does the facility emit, or have the potential to emit, more than 10 tons/yr of any single hazardous air pollutant (HAP), or more than 25 tons/yr of total HAPs ... 

EPA must promulgate a list of categories and subcategories of major sources and area sources of listed hazardous air pollutants. 

If necessary, EPA is required to promulgate regulations to control the atmospheric deposition of hazardous air pollutant to surface and coastal waters. 

EPA is required to promulgate standards for all listed categories and subcategories of sources of hazardous air pollutants. 

The CAAA90 offers a comprehensive plan for achieving significant reductions in emissions of hazardous air pollutants from major sources. The new law will improve EPA s ability to address this problem effectively and it will accelerate progress in controlling major toxic air pollutants. 

List of Pollutants and Source Categories The law lists 189 hazardous air pollutants. One year after enactment EPA lists source categories (industries) which emit one or more of the 189 pollutants. In two years, EPA must publish a schedule for regulation of the listed source categories. 

List five categories (such as hazardous waste incineration) that may be considered as major" or "area sources of hazardous air pollutants,... 

Before the U.S. Clean Air Act Amendments of 1990 (3), hazardous air pollutants were regulated through federal promulgation of the National Emission Standards for Hazardous Air Pollutants (NESHAPS). The EPA listed only eight hazardous air pollutants under NESHAPS. 

Title III of the 1990 amendments completely changed the U.S. standards for the hazardous air pollutant control program. Stensvaag (6) has summarized these changes as follows ... 

Massively expand the list of hazardous air pollutants. This inihal list contained 189 hazardous air pollutants. 

EPA Federal Register, National Emission Standards for Hazardous Air Pollutants for Source Categories Aerospace Manufacturing and Rework Facilites 60, 170 p. 45947, 1995. 

Free phenol is a major concern in the manufacture of novolac resins. This is true for several reasons. The strongest drivers are probably EPA classification of phenol as a Hazardous Air Pollutant and worker safety concerns. However, free phenol also has significant technical effects on such parameters as melt flow characteristics. In this role, free phenol may undermine the desired effects of a molecular weight design by increasing flow beyond the desired point. Since free phenol is often variable, the effects on flow may also cause variation in product performance from batch to batch. Fig. 18 shows the effects of free phenol on the flow across a series of molecular weights. Free phenol contents between 1 and 10% are commonly seen. In recent years, much work has been aimed at reducing the free phenol. 

TANKS This program estimates volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions from fixed- and floating-roof storage tanks. TANKS is based on the emission estimation procedures from... 

This equipment is used for the capture of Particulate Matter (PM), including particulate matter less than or equal to 10 micrometers ( m) in aerodynamic diameter (PMk, particulate matter less than or equal to 2.5 m in aerodynamic diameter (PMj 5), and hazardous air pollutants (HAPs) that are in particulate form, such as most metals (mercury is the notable exception, as a significant portion of emissions are in the form of elemental vapor). 

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