Methanol: A Hazardous Air Pollutant? Understanding The Risks

The Clean Air Act (CAA) requires the Environmental Protection Agency (EPA) to regulate emissions of hazardous air pollutants (HAPs). The HAP list includes organic and inorganic substances associated with adverse health effects, including cancer, neurological issues, and developmental problems. One such HAP is methanol, a hazardous substance emitted from miscellaneous organic chemical (MON) manufacturing facilities.

Methanol is a hazardous air pollutant

The Clean Air Act requires the US Environmental Protection Agency (EPA) to regulate emissions of hazardous air pollutants. The EPA maintains a list of hazardous air pollutants (HAPs) that includes organic and inorganic substances associated with a wide variety of adverse health effects, including cancer, neurological issues, and respiratory irritation.

The National Emission Standards for Hazardous Air Pollutants (NESHAP) have been established to regulate and limit the emissions of HAPs, including methanol, from miscellaneous organic chemical (MON) manufacturing facilities. These standards ensure that major sources of HAP emissions, such as MON manufacturing plants, meet specific standards and apply the maximum achievable control technology (MACT) to minimize the release of these harmful substances into the atmosphere.

The inclusion of methanol on the HAP list highlights the importance of regulating and controlling its emissions to protect human health and the environment. By recognizing methanol as a hazardous air pollutant, the EPA can implement measures to reduce its impact and safeguard the well-being of individuals who may be exposed to this toxic substance.

It is important to note that the HAP list is subject to modifications, with substances being added or removed based on ongoing research and public petitions. The EPA continuously evaluates and amends the list to ensure that appropriate action is taken to mitigate the adverse effects of hazardous air pollutants like methanol.

Clean Air Act and hazardous air pollutants

The Clean Air Act (CAA) requires the Environmental Protection Agency (EPA) to regulate emissions of hazardous air pollutants. The original list included 189 pollutants, and since 1990, the EPA has modified the list through rulemaking to include 188 hazardous air pollutants. The EPA has the authority to add or remove substances from the list. For instance, in January 2022, the EPA issued a final rule to add 1-bromopropane (1-BP) to the Clean Air Act's list of hazardous air pollutants. The EPA determined that 1-BP is an air pollutant and that its emissions and ambient concentrations may cause adverse effects on human health.

The EPA has also removed several substances from the list of hazardous air pollutants over the years. For example, Methyl Ethyl Ketone was removed from the list in December 2005, and Ethylene glycol monobutyl ether (EGBE) was removed from the list in November 2004. The EPA continues to update and modify the list of hazardous air pollutants to reflect the latest scientific and technical information.

The Clean Air Act plays a crucial role in protecting human health and the environment from the harmful effects of air pollution. It establishes comprehensive regulations to reduce and control emissions of hazardous air pollutants from various sources, including industrial facilities, vehicles, and power plants. The EPA sets National Ambient Air Quality Standards (NAAQS) for six common air pollutants: particle pollution, lead, carbon monoxide, ground-level ozone, sulfur dioxide, and nitrogen dioxide. These standards ensure that the air quality in the United States meets specific health and welfare criteria.

Additionally, the Clean Air Act authorizes the EPA to establish National Emission Standards for Hazardous Air Pollutants (NESHAPs) for certain industrial sectors. These standards aim to reduce emissions of hazardous air pollutants, such as toxic chemicals and heavy metals, which are known to pose significant risks to human health and the environment. The EPA also works closely with state and local governments to implement and enforce air pollution control measures.

The Clean Air Act provides a comprehensive framework for regulating air emissions and protecting public health. By authorizing the EPA to establish and enforce standards for hazardous air pollutants, the Act helps ensure that the air we breathe is safe and clean. The EPA's ongoing efforts to update and modify the list of hazardous air pollutants demonstrate its commitment to incorporating the latest scientific knowledge and protecting human health and the environment from the detrimental effects of air pollution.

Health effects of hazardous air pollutants

Hazardous air pollutants (HAPs) are regulated by the EPA under the Clean Air Act, which initially listed 189 pollutants but has since been modified to include 188. HAPs can cause cancer, birth defects, or other serious harm. The specific health effects depend on the pollutant in question, and the concentration and duration of exposure. For example, mercury is a toxic air pollutant that can deposit onto soils or surface waters, where it is taken up by plants and ingested by animals, eventually magnifying through the food chain.

People exposed to HAPs may experience an increased chance of getting cancer, as well as other serious health problems. These health issues can include damage to the immune system and neurological, reproductive, developmental, and respiratory problems. For instance, HAP exposure can lead to reduced fertility.

Indoor air can also contain hazardous air pollutants, including tobacco smoke, asbestos, and consumer products like cleaning supplies and air fresheners. Major sources of outdoor toxic air pollutants include emissions from coal-fired power plants, industries, refineries, and vehicles such as cars, trucks, and buses. Certain industries also produce specific air toxins.

The EPA maintains two nationwide databases that provide information on emissions: the National Air Toxics Assessment and the Toxics Release Inventory. These databases help to identify the greatest threats to public health in urban areas and allow individuals to learn about releases of toxic chemicals into the environment through air, water, and land from manufacturing facilities.

Hazardous air pollutant emissions

Hazardous air pollutants (HAPs) are regulated by the US Environmental Protection Agency (EPA) under the Clean Air Act (CAA). The CAA HAP list includes organic and inorganic substances associated with a wide variety of adverse health effects, including cancer, neurological, reproductive, and developmental effects. The health impact of HAPs depends on factors such as the toxicity of the substance, the amount of exposure, and the duration and stage of life at which exposure occurs.

The EPA has established National Emission Standards for Hazardous Air Pollutants (NESHAP) for various industries, including the miscellaneous organic chemical (MON) manufacturing industry. NESHAP sets emission limits and work practice standards for new and existing MON manufacturing process units, wastewater treatment, conveyance systems, transfer operations, and associated ancillary equipment.

Methanol is specifically listed as a HAP emitted from MON manufacturing facilities. Other HAPs emitted from these facilities include toluene, ethylene oxide, xylene, hydrogen chloride, and methylene chloride. Exposure to these substances can have adverse health effects, including irritation of the lungs, eyes, and mucous membranes, as well as impacts on the central nervous system and an increased risk of cancer.

The EPA actively modifies the list of HAPs to reflect new findings and public petitions. For instance, in January 2022, the EPA issued a final rule to add 1-bromopropane (1-BP) to the CAA's list of HAPs. This decision was made in response to public petitions and the EPA's determination that 1-BP is an air pollutant with potential adverse effects on human health.

Regulations on hazardous air pollutants

Hazardous air pollutants are those known to cause cancer and other serious health issues. The Clean Air Act (CAA) requires the Environmental Protection Agency (EPA) to regulate emissions of hazardous air pollutants. The CAA also requires major stationary sources to install pollution control equipment and meet specific emissions limitations.

The EPA's approach to understanding and regulating hazardous air pollutants involves monitoring hazardous air pollutant emissions and ambient data to develop regulatory programs that limit emissions from stationary sources. The EPA also sets protective limits on emissions and informs people about radiation and radiation hazards.

The initial list of hazardous air pollutants included 189 pollutants. Since 1990, the EPA has modified the list through rulemaking to include 188 hazardous air pollutants. Some examples of pollutants that have been added or removed include:

• 1-bromopropane, added to the list in 2022
• Methyl Ethyl Ketone, removed from the list in 2005
• Hydrogen Sulfide, added to the list inadvertently but removed by Congress with Presidential approval in 1991

The term "hazardous air pollutant" refers to any air pollutant listed pursuant to subsection (b). The Administrator is responsible for listing each category or subcategory of area sources that present a threat of adverse effects to human health or the environment. The Administrator must also list, based on actual or estimated aggregate emissions of a listed pollutant, sufficient categories or subcategories of area sources to ensure that area sources representing 90% of the area source emissions of the 30 hazardous air pollutants that present the greatest threat to public health are subject to regulation.

Frequently asked questions