EPA Decision Increases Hazardous Air Pollution Risk

Maps show locations of facilities with reduced pollution control requirements

Published Apr 20, 2018 Updated Jun 13, 2019

The Clean Air Act has a long record of keeping Americans safe from air pollution and its damaging health effects. A recent decision by Environmental Protection Agency Administrator Scott Pruitt threatens to walk back these vital protections.

Potential emissions increases by congressional district

The Clean Air Act has a long record of keeping Americans safe from air pollution and its damaging health effects. A recent decision by Environmental Protection Agency Administrator Scott Pruitt threatens to walk back these vital protections.

Rolling back public health protections from air pollution

In 1995, the EPA created the OIAI policy to close a loophole in regulation of emissions of hazardous air pollutants (HAPs). EPA regulates 187 HAPs, such as benzene, formaldehyde, and acrolein, many of which are strongly linked to cancer, respiratory disease and other health effects.

“Once in, always in” meant that once an industrial facility was determined to be a major source of HAPs, it would always be required to employ strong pollution controls through a measure called the Maximum Achievable Control Technology (MACT) to reduce HAP emissions. Sources must apply MACT to reduce HAP emissions if they emit more than 10 tons per year (tpy) for a single hazardous chemical or 25 tpy of combined hazardous chemicals on a proscribed list known to have major health impacts.

MACT has been very effective. We estimate that in 2014, 70 percent of all major sources were using MACT to emit at or below the 10 or 25 tons per year threshold for hazardous air pollutants. But on January 25, 2018 the EPA withdrew the OIAI policy, allowing a major source to be reclassified as an “area source” if it can show that its potential to emit hazardous air pollutants falls below the standard.

It is important to note that if a plant’s emissions fall below the thresholds for major sources, that does not imply “safe” levels of emissions. The EPA has stated that pollutants controlled by MACT are hazardous even in low concentrations. Instead, the thresholds are meant to classify larger and smaller emitters.

Although area sources must also meet pollution standards, they are not regulated nor inspected as stringently as major sources. Because area sources aren’t required to use MACT, their pollution reduction will not be as effective. In fact, hazardous air pollution could increase for major sources that are reclassified as area sources.

Reporting and monitoring requirements are also different for area sources, which raises the question: how would the EPA or the public know if an area source has increased their emissions over the major source standard? And if so, when should such sources be reclassified as a major source? The EPA’s new policy guidance does not answer these questions. As a result, the public and the EPA are left in the dark. Without effective enforcement, pollution may be increasing, needlessly exposing people to unsafe levels of hazardous air pollutants.

Facilities affected by the EPA rule change

Most major sources subject to MACT controls could see their emissions increase significantly under the withdrawal of the “once in, always in” policy. The size of the dot indicates the difference between that facility’s current emissions and the threshold of 25 tons per year, which represents the increase permitted by this rule change.

Hazardous air pollutants harm our health

Inhalation and other forms of contact with hazardous air pollutants can severely harm human health. Increasing emissions of these pollutants from industrial sources will put more people, especially fenceline communities and workers, in harm’s way.

  • Chlorine and hydrochloric acid, for example, can inflame the lungs and airways. Acute exposure to chlorine resulted in the death or hospitalization of dozens of people following an industrial train derailment in South Carolina in 2005.
  • Styrene, another hazardous air pollutant, is a very common solvent used to make plastics and synthetic rubber. Workplace exposure to styrene has been linked to degenerative disorders like multiple sclerosis and other disorders similar to Parkinson’s Disease.
  • Exposure to benzene—used to make dyes, plastics, detergents, and pesticides—causes leukemia and other blood cancers.
  • While skin contact with naphthalene can irritate the skin, breathing or swallowing large amounts can lead to the breakdown of red blood cells.

We estimate these substances and several others to be among the top ten hazardous air pollutants by volume and toxicity emitted by major toxic sources in the United States.

Top 10 hazardous air pollutants by total emissions and toxicity emitted by major sources in 2014.

Hazardous Air PollutantTotal 2014 emissions (tpy)1Reference Concentration (Toxicity)2
Chlorine 2325 1.50E-04
Hydrochloric Acid 38084 2.00E-02
Styrene 8022 2.00E-02
Manganese Compounds 314 5.00E-05
Xylene and Mixed Isomers 4466 1.00E-01
Benzene 1910 3.00E-02
n-Hexane 12743 7.00E-01
Naphthalene 398 3.00E-03
1-3-Butadiene 264 2.00E-03
Chloromethane 644 9.00E-02

Many states will see large increases in toxic emissions

Pruitt’s new guidance will impact states very differently. Some states rely only on federal protections from hazardous air pollutants, while others set their own emission limits. Some of the states that set their own standards allow pollutant emissions on a case-by-case basis, while others have set more stringent standards for hazardous air pollutants across the board.

The states that rely solely on federal regulations will be affected most by the EPA’s new guidance. Without state-level protections in place, the EPA’s move will allow facilities in these states to remove pollution control technologies and emit more hazardous air pollutants. This emissions increase may also occur in states that address area sources on a case-by-case basis, or states that have their own area sources standards – but exactly how much of an increase depends on each state’s regulations, which often have separate standards for each pollutant and each type of source (e.g. dry cleaners, chemical plants, etc).

Overall, the new EPA guidance will allow for a potential increase in hazardous air pollutant emissions in many places across the U.S. Here’s a look at how it might affect your state.

  • At least 21 states could see more hazardous air pollution under the EPA’s new guidance.
  • In Louisiana, the area along the Mississippi River between Baton Rouge and New Orleans known as “Cancer Alley” due to heavy clustering of industrial facilities, contains 42 facilities that could see emissions increase.
  • In the New York-Newark urban area, including parts of Connecticut, 26 out of 28 facilities could see emissions increases.
  • 35 out of 41 facilities in the Chicago urban area could experience emissions increases.
  • 37 out of 50 facilities in Houston, TX could experience emissions increases among low-income, communities of color already overburdened with petrochemical toxics.
  • In addition, a few cities could experience cumulative toxic exposures due to multiple facilities with high potential emissions increases clustered together within 30 miles of each other.
    • 42 facilities in or around Philadelphia, PA.
    • 15 facilities in or around the Minneapolis-St. Paul metro region.
    • 14 facilities in or around Louisville, KY.
    • 12 facilities in or around Cincinnati, OH.
    • 7 facilities in or around Boston, MA.

Take action

There are many ways you can speak up about the concerns you have about the potential for the facilities in your community to release hazardous air pollutants due to this reduction in public protections.

  • If you live in a state where toxic air pollution might increase, push your state legislators to enact stronger state-level laws to protect your community from toxic air pollutants. Below are some ways to engage – consult these tips on communicating with policymakers.
  • Inquire with your state air agency how your area might be affected by the changes to the “once in, always in” mandate. Find your state agency on the EPA site.
  • Utilize the media to bring attention to the issue. Write a letter to the editor, Op-Ed, or meet with local journalists or editorial boards about your concerns. See these tips on best practices.
  • Directly contact the company that operates the facility near you, and ask them to commit to maintaining their classification and use of MACT technology and requirements. Follow-up if you don’t hear back in a week and utilize their response (or lack thereof) to hold them accountable for their actions, and/or to show the media, your policymakers, and the public what they are saying.
  • Tell EPA Administrator Scott Pruitt to do his job of carrying out the EPA’s mission of protecting public health and the environment by rescinding the new guidance.
    • Tweet at EPA Administrator Scott Pruitt, the EPA, and tag your members of congress.

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Download the data files and methods used in this analysis >

1: 2014 National Emissions Inventory, the most recent year available.

2: EPA. Health Effects Information Used In Cancer and Noncancer Risk Characterization for the 2005 National-Scale Assessment. The reference concentration is an estimate of an inhalation exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risks of deleterious effects during a lifetime. In other words, exposure to pollutant levels above the reference concentration could post risks to human health.

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