Principal Investigator: Vipin Varma, Ph.D., Vice President – Air Quality, Director of the Southern Regional Center, NCASI

Collaborators: The United States Environmental Protection Agency (EPA), National Risk Management Research Laboratory (NRMRL) and the Office of Air Quality Planning and Standards (OAQPS)

Supported by: NCASI Foundation

Project Summary: The objective of this project is two-fold. The first is to compare CPM measurement using EPA Method 202 and OTM-037. Secondly, speciation of PM at various locations along each method’s sampling setup will inform whether the method itself is affecting CPM formation, and if so, to what degree. The comparative measurements and PM speciation studies will be used to evaluate an approach to quantify primary CPM. Related to this, speciation as a function of time, dilution, relative humidity, etc. will provide further insight as to what near-stack conditions promote CPM formation and the types of practices that are appropriate for those conditions. These methodology comparisons and kinetics investigations will aid in the ongoing research pursued by NRMRL to refine methods and better understand CPM formation. Ultimately, this research will support the Office of Air Quality Planning and Standards (OAQPS) and their understanding of the application of Method 202 and OTM-037 for regulatory purposes.

Contact Vipin Varma at