Three Decades of Condensable Particulate Matter (CPM) Regulation

2017-03-17 Three Decades of CPM Regulation


Condensable Particulate Matter (CPM) is material that is in a vapor state at stack conditions, but condenses and/or reacts upon cooling and dilution in the ambient air to become solid or liquid Particulate Matter (PM) immediately after discharging from the stack.  All CPM is assumed to be in the PM2.5 size fraction.


1987  After promulgating the PM10 National Ambient Air Quality Standards (NAAQS) the EPA began recommending that, in certain circumstances, states consider including the condensable portion of PM10 emissions in the determination of total and fine PM emissions from major stationary sources.

1991  EPA Promulgated Method 202.  The original Method used wet impingers – in which sulfur dioxide was captured and formed sulfur trioxide and sulfuric acid artifacts. This caused captures to be biased high by improperly quantifying the sulfuric artifacts as condensable PM.

2008  73 FR 28321 (May 16, 2008) 2008 PM2.5 New Source Review (NSR) Implementation Rule.  The EPA revised the definition of “regulated NSR pollutant” for both Prevention of Significant Deterioration (PSD) and nonattainment NSR to require that CPM be considered in applicability determinations and in establishing emissions limits for “particulate matter emissions2,” “PM10 emissions,” and “PM2.5 emissions.”

Although, citing various concerns regarding the uncertainties associated with Method 202, the EPA announced that it would not require states to implement the requirement to account for CPM in establishing enforceable emissions limits for either PM10 or PM2.5 in permits until the completion of a transition period that ended on January 1, 2011.

2010  75 FR 80118 (December 21, 2010).  Method 202—Dry Impinger Method for Determining Condensable Particulate Emissions from Stationary Sources was promulgated. Sample collection and recovery procedures were revised to reduce artifact formations. Further, many options regarding sample analysis were removed to increase consistency and precision of the method.

2012  77 FR 65107 (October 25, 2012).  CPM was removed as a requirement for measuring PM, but the CPM requirement was not removed from PM2.5 or PM10 emissions.

2014  Interim Guidance regarding Method 202. The EPA issued Interim Guidance while it investigated industry shareholder concerns that EPA Method 202 may bias test results high due to various environmental and chemical conditions.

This granted air agencies to permit applicants to use field train proof blanks in lieu of field train recovery blanks and to allow blank values as high as 5.1 mg to be used in the calculation of CPM. This interim guidance applied for the purposes of (1) determining source applicability to PSD or nonattainment NSR with respect to PM10 and/or PM2.5; (2) conducting the air quality analyses required to obtain a PSD permit; (3) determining the quantity of required emissions offsets in nonattainment areas; and (4) conducting the necessary compliance tests.

2016  The EPA developed the Method 202 Best Practices Handbook to assist stack testers in achieving the expected results when using EPA Method 202—Dry Impinger Method for Determining Condensable Particulate Emissions from Stationary Sources.

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ESS provides emissions testing, air quality analysis, and ambient air testing services for municipal water treatment plants, public utilities, manufacturers, paper mills, and other industrial facilities in the US and overseas.  Since its inception in 1979, ESS has conducted thousands of emissions tests and provided countless hours of environmental consulting services.  ESS specializes in conducting the EPA testing methods for all applicable EPA subparts, such as: NSPS (40 CFR 60), NESHAP (40 CFR 63), RATA (40 CFR 75), and various other federal and state regulations.

Call us at 910.799.1055 to request a quote for engineering or compliance test projects including Condensable Particulate Matter (CPM) by EPA Method 202 or any other criteria.

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