Dust Should Not be Regulated as Fine Particulate Matter
under the National Ambient Air Quality Standards of the Clean Air Act

NCBA Staff Contact: 

Tamara Thies, Chief Environmental Counsel
202-347-0228

tthies@beef.org

Every five years, the EPA is required to review scientific studies associated with “criteria pollutants” regulated under the National Ambient Air Quality Standards (NAAQS) of the Clean Air Act to determine if the pollutant is regulated appropriately.  One of the criteria pollutants is particulate matter (PM, including dust).  The NAAQS is a health-based standard.  In other words, Congress determined that in order to regulate a pollutant under the NAAQS, scientific studies must show that the pollutant causes adverse health effects.  Conversely, if scientific studies do not show that a pollutant causes adverse health effects, it is not supposed to be regulated under the NAAQS. 

Prior to 1997, the EPA regulated PM with a standard of 150µg/m³ which applied to all PM in the size range of ten microns or smaller (PM10).  In 1997, the EPA decided to separate particles for regulatory purposes based on their composition and size since it was believed that these factors make a difference as far as health effects are concerned.  “Fine” PM (PM2.5) formed primarily by combustion or chemical reaction of gases falls in the size range of 2.5 microns or smaller.  “Coarse” PM (PM10) formed by mechanical processes consisting of minerals, crustal material and organic debris, i.e. dust, falls in the size range of 10 microns and smaller.  In 1997, the NAAQS for PM2.5 was 65µg/m³, the NAAQS for PM10 was retained at 150µg/m³.  In 2006, the EPA tightened the PM2.5 standard to 35µg/m³ and retained the PM10 standard of 150µg/m³.

After the EPA publishes its standards for regulating PM, it issues an “Implementation Rule” which outlines requirements states must meet when developing plans to control and reduce fine PM to ensure attainment status.  On April 25, 2007, the EPA published the “Clean Air Fine Particle Implementation Rule” for regulation of the 1997 fine PM (PM2.5) standard – that’s right, it took the EPA 10 years to issue this rule.  Normally, NCBA would not be concerned about the fine PM standard since our operations do not emit fine PM formed by combustion or the chemical reaction of gases that are of concern to the EPA.  Unfortunately, however, the EPA inappropriately opted for the administrative convenience of regulating all particles that fall within the fine PM size range the same, including dust, instead of appropriately basing its regulation on particle composition.  Incredibly, this decision treats dust as though it causes the same adverse health effects as cigarette smoke.  There are no scientific studies that show this is true.  This decision creates problems for the cattle industry since an EPA study shows that 80-90% of feedyard dust can fall within the PM2.5 size range.  Compliance with the more stringent fine PM standard will be unattainable for many cattle operations.  Like the coarse PM standard, the fine PM standard is health-based and must be met at the property line of each individual cattle operation regardless of cost.  If compliance is not attained after the use of BMPs, cattle operations may be forced to sell cattle to comply.

Because of the inappropriateness of EPA’s decision to regulate dust under the fine PM standard, NCBA filed a petition for reconsideration of the rule with the EPA, and filed an appeal with the DC Circuit Court of Appeals.  The appeal is stayed pending the outcome of the petition for reconsideration which we expect an answer on during 2008.