Forensic Analysis of Condensable Particulate (CPM)
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.
The U.S. EPA signed an amendment to the rule on February 28, 2022 that removes the stay of the formaldehyde limit for lean premix and diffusion flame gas-fired units that were constructed or reconstructed after January 14, 2003.