Condensable Particulate Matter emission limits have been on the rise in multiple states and are affecting many industries. EPA Method 202 was written to quantify particulates that condense at ambient conditions and has been revised numerous times to reduce interference and increase effectiveness. Even still, ESS is regularly contacted by facilities across the country who struggle to produce accurate condensable results.

There are several things facilities should watch out for if they receive unexpected results. In this series ESS will look at condensable particulate matter stack test practices in depth. While increasing the number of blank analyses can be costly, it is important to understand the importance of each blank in determining accurate condensable particulate matter.

·         Field Train Recovery Blanks: The intent of field train recovery blanks is to measure the lowest achievable mass contribution background resulting from the entire Method 202 sampling and analysis process. Is the value less than 2.0 mg? If yes, then that means there was minimal contamination from contributors such as field reagents, sampling train carry-over, sample recovery and analysis. If no, then further analyses must be conducted.

·         Field Train Proof Blanks: The intent of field train proof blanks is to measure the lowest achievable mass contribution background resulting from the entire Method 202 sampling and analysis process. This blank is regularly archived and analyzed if the recovery blank value exceeds 2.0 mg. The proof blank should always be conducted if it is not possible to bake all glassware associated with the sampling train. If the proof blank exceeds 2.0 mg catch weight, then carry-over contamination has occurred or field reagents are contaminated.

·         Field Reagent Blanks: Field reagent blanks differ from laboratory reagent blanks since they are collected in the field from the wash bottle used onsite. The field reagent blank should be no greater than 0.1mg heavier than the laboratory reagent blank. The field reagent blank quantifies the amount of residual mass contributed to the sample from the reagents, the wash bottles, and that these mass contributions were maintained at a low level during testing.

Look for our next Condensable Particulate Matter overview to understand the next steps to understanding your EPA Method 202 stack test results. Contact us at [email protected] to get a quote.