–Air toxics are
gaseous, aerosol, or particle pollutants present in the air in varying concentrations with characteristics
such as toxicity or persistence
that can be hazardous to human, plant, or animal life.
–The terms “air toxics”
and “hazardous air pollutants” (HAPs) are used interchangeably in this document.
–Air toxics include the
following general categories of compounds: volatile and semi-volatile organic compounds (VOCs,
SVOCs), polycyclic aromatic
hydrocarbons (PAHs), heavy metals, and carbonyl compounds.