Discussion and Evaluation of the Volatility Test for Equivalency of Other Methods to the Federal Reference Method for Fine Particulate Matter

In July, 1997, the EPA promulgated a new National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM 2.5 ). This new standard was based on the collection of an integrated mass sample on a filter. Field studies have demonstrated that the collection of semivolatile compounds leads to artifacts and imprecision among methods. In view of such sampling artifacts, a test requirement was promulgated in Title 40, Part 53, Subpart F, Section 53.66 of the Code of Federal Regulations (40CFR53.66) to aid in the determination of methodological equivalency. In this paper, this requirement is critically reviewed and tested in terms of its feasibility and precision. The results show that the test is capable of demonstrating acceptable precision for FRM-type samplers and repeatable differences in performance among different methods. In order to maintain high precision within the entire test procedure, the loading time should be extended to 2 h for flow rates of 16.7 lpm and proportionately longer for lower flow rates.