TABLE 1-1 Substances in AFO Emissions That the Committee Was Tasked to Address and Their Respective Classificationsa

Species

Criteria Pollutant

Hazardous Air Pollutant (HAP)

Greenhouse Gas

Regulated Air Pollutant

NH3b

X

N2Oc

X

NOx

X

X

CH4

X

VOCsd

Xe

Xf

H2Sg

X

PM (TSP)h

X

PM10

X

X

PM2.5

X

X

Odori

X

aSee Appendix B for definitions and Chapter 6 for regulations.

bAmmonia is not a criteria pollutant but is a precursor for secondary PM2.5, which is a criteria pollutant.

cNitrous oxide is not a precursor for the formation of tropospheric ozone, but is a greenhouse gas. It is not considered to be part of NOx (the sum of NO and NO2), which contributes to formation of ozone, a criteria pollutant.

dVolatile organic compounds (VOCs), sometimes referred to as reactive organic gases (ROGs), contribute to the formation of ozone, a criteria pollutant.

eSome, but not all, VOCs are listed as Hazardous Air Pollutants (HAPs).

fSome VOCs are regulated as HAPs, and some are regulated as ozone precursors.

gHydrogen sulfide is not listed as a criteria pollutant or a hazardous air pollutant (HAP). However, it is a regulated pollutant because it is listed as having a New Source Performance Standard (NSPS). It may be added to the HAPs list in the near future.

h Particulate matter. Prior to 1987, PM was a criteria pollutant and regulated as total suspended particulate (TSP). Currently, the PM fractions listed as criteria pollutants are PM10 and PM2.5. However, TSP emissions are regulated in some states.

iOdor is a regulated pollutant in some states. State air pollution regulatory agencies regulate it based on a nuisance standard.

adverse impact on air emissions. The committee was also asked to assess the approach for estimating air emissions from AFOs presented in a draft contract report to EPA Emissions from Animal Feeding Operations (EPA, 2001a). The committee’s interim report provided EPA with findings on the following: identification of the scientific criteria needed to ensure that air emission rates are reasonable, the basis for these criteria as documented in the scientific literature, and the uncertainties associated with them. The interim report was reviewed in accordance with National Research Council procedures. It responded directly to a series of questions posed by EPA:

  • What are the scientific criteria needed to ensure that reasonably appropri-



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