EPA Method 5I - Particulate Emissions

Method Overview

  • Isokinetic.
  • Heated out of stack filter (M5).
  • "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.

Target Compounds

  • Particulate Matter (PM) -- those substances retained in the sampling nozzle/probe and on a heated filter after the removal of uncombined water.

Performance Tips

  • A minimum sample catch of 50 mg is targeted to calculate the minimum sample times
    • An absolute minimum of 3 mg catch is required;
    • Any expected catch of less than 50 mg will require the use of EPA Alternative Method 005 to process the samples.
  • During sampling a filter is maintained at a specified temperature (248oF + 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.
  • Stainless steel nozzles should be used with great care, port scrapings can bias results high.


  • 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.


  • The EPA's first attempt (promulgated in 1999) at measuring very low mass particulate catches.
  • Clean Air has implemented many of the quality improvements from Method 5I into all of our gravimetric analyses.
    • These low emissions measurements can now be possible using any gravimetrics technique (EPA M5, EPA M201A, EPA M202, etc.).
    • Method 5I Lists the MDL as 0.5 mg. Clean Air Routinely quantifies our MDL at around 0.25 mg, for all sample matrices.
  • Your target sample catch should be around 1-1.5 mg total, using our MDL as a guideline:
    • EPA M5I suggests 3 mg as a target catch with a specified MDL of 0.5 mg.
    • Clean Air can cut your sampling time in half, saving field time and money.


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