EPA Method 5B - Non-Sulfuric Acid Particulate Emissions

Method Overview

  • Isokinetic.
  • Heated out of stack filter at 320oF + 25oF.
  • "Condensible" particulates pass through the filter and condense in impingers. Can readily be combined with a CPM Method.
  • Tester may adjust out-of-stack filter temperature to suit source specific conditions.
  • Stainless steel nozzles should be used with great care, port scrapings can bias results high.

Target Compounds

  • non-Sulfate Particulate Matter (nSPM) -- those substances retained in the sampling nozzle/probe and on a heated filter.

Performance Tips

  • During sampling a filter is maintained at a specified temperature (320oF + 25oF)
  • Do not use silicone grease - it can be soluble in the probe rinse and can bias the PM value high.
  • Run the train isokinetically.
  • Following evaporation of rinses, all samples are heated in an oven at 160oC (320oF) for six hours to volatilize any condensed sufluric acid that may have been collected.


  • Acetone must be shipped as a hazardous material. Please call for IATA codes if you need them.
  • Samples may be shipped at ambient temperatures.
  • It may prove more economical to keep acetone rinses separate, ship other samples normally, and the acetone as hazardous.
  • Be sure to include a chain of custody for each shipping container.


  • This method was originally developed for determining non-Sulfate (filterable) particulate matter from 'applicable sources' where it is called for in the applicable subparts.
  • Clean Air has had success in baking samples that were obtained using regular Method 5 sampling temperatures.
    • First, we attempted to obtain constant weights simply with desiccation. The presence of sulfuric acid droplets prevented this.
    • Next, we baked these samples at 100oC for two hours. This removed nearly 50% of the mass in that instance. But, the mass was again not quite stable.
    • Next, we baked these samples at 160oC for six hours. This removed another 50% of the remaining mass. It also stabilized the mass (constant weights were attainable).


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