New Clean Air Act standards for fine particulate matter (“PM2.5”), including soot, were recently announced by the United States Environmental Protection Agency (“EPA”).  EPA reduced the National Ambient Air Quality Standard for PM2.5 from 15.0 micrograms per cubic meter (µg/m3) to 12.0 µg/m3. EPA’s action came in response to the U.S. Court of Appeals for the District of Columbia Circuit decision which required EPA to clarify how the PM2.5 standard affords necessary protection from short- and long-term exposures to soot, placing emphasis on protecting at-risk populations like children. 

EPA derived the new soot emissions rule from “an extensive body of scientific evidence,” including new epidemiological, toxicological, and controlled human exposure studies revealing the negative health impacts of soot even after short-term exposure. According to EPA, the new evidence “expands our understanding of cardiovascular and respiratory effects related to short-term ultrafine particle exposures.” Despite the new scientific findings, however, EPA admitted that the evidence was “still very limited.”

Under the new rule, EPA will compile a list of non-attainment areas in 2014. These areas must then attain compliance by 2020. Despite the new standard, EPA predicts that 99 percent of U.S. counties will meet it. EPA attributes the high projected attainment rate to “build[ing] on smart steps already taken by EPA to slash dangerous pollution in communities across the country.”

EPA’s new rule has teeth too. In addition to imposing federal fines on local governments that fail to take prescribed action, the rule contains more stringent permitting requirements making it harder for new pollution sources to obtain operating permits in non-attainment areas. Conversely, the rule offers incentives to reduce soot emissions. However, the incentives currently have little financial backing.

Ultimately, EPA forecasts considerable direct health benefits, including decreased mortality rates, fewer heart attacks, strokes, and childhood asthma, all coming at “comparatively low costs.” Specifically, EPA has estimated the overall health benefits to fall between $4 billion to $9 billion per year while implementation costs range from $53 million to $350 million annually.

Irrespective of the rule’s potential benefits, not all groups welcome the new regulation. For example, several manufacturing trade groups believe that the EPA could protect the public health and welfare with a less stringent standard. These concerns are particularly noteworthy in light of an uncertain economy and potential fiscal crisis. In addition to the burden placed on existing facilities, companies looking to expand operations may be deterred from making new, job-creating investments due to local governments’ fears that new plants could cause compliance issues.