EPA Method 202 defines condensable particulate matter (CPM)
as material that is vapor phase at stack conditions, but which condenses and/or
reacts upon cooling and dilution in the ambient air to form solid or liquid PM
immediately after discharge from the stack. Note that all CPM, if present from
a source, is typically in the PM2.5 size fraction and, therefore, all of it is
a component of both primary PM2.5 and primary PM10.
That still does not answer the most basic question: “What’s
in my CPM?”. Many compounds can condense and form particulate matter at ambient
conditions. Identifying which compound is most prevalent can help in
determining control measures to reduce CPM.
Analysis can be conducted to identify likely organic or
inorganic compounds in the rinse residue. A problem arises when there is no
known compound in the gas stream that could cause high results. Forensic
technologies such as scanning electron microscopy combined with energy
dispersive x-ray spectrometry (SEM-EDS) utilize automated particle recognition
followed by chemical analysis of each particle in the form of EDS Spectrum.
This technology allows us to determine what kind of particles are in the
samples as well as the chemical composition of the particles without narrowing
the scope to known compounds. The same analysis can be conducted on filterable
particulate collected by EPA Method 5 or EPA Method 201a.
If your emission source is struggling with particulate
matter emission limits, contact ESS for a detailed review of your permit, past
emissions test, and a plan of action to achieve compliance.