Method 5
Determination of Particulate Matter Emissions From Stationary Sources
40 CFR Part 60, Appendix A-3
From the method — regulatory text
Sections 1.0 and 2.0 of Method 5—Determination of Particulate Matter Emissions From Stationary Sources, as published at 40 CFR Part 60, Appendix A-3. Retrieved 10/07/2026. The full method is on the eCFR.
1.0 Scope and Application
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of PM emissions from stationary sources.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.0 Summary of Method
Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature of 120 ±14 °C (248 ±25 °F) or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application. The PM mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water.
EssentialRegs notes
Our plain-English reading of Method 5. Not the method text.
What it measures
The mass of particulate matter emitted from a stack, as the material collected on a heated filter from a measured volume of stack gas, reported as a concentration or an emission rate.
How it works
Stack gas is drawn through a probe and a heated filter at a rate that matches the velocity of the gas in the stack at each sampling point, so that the sample is representative of what is actually leaving the stack. The filter and probe are weighed before and after, and the particulate caught is related to the volume of gas sampled. Because the sampling rate must track the stack velocity point by point, Method 5 is always run with the methods that locate the sampling points and measure velocity, molecular weight and moisture.
Equipment
A Method 5 sampling train: a heated probe and filter, impingers in an ice bath, a pump, a dry gas meter and a pitot tube, with the filter weighed on an analytical balance.
When a rule cites it
Performance tests to show a particulate emission limit is met, usually for combustion equipment, boilers, engines and process stacks. It is invoked where a rule needs a measured particulate mass rather than an opacity reading.
Notes for compliance staff
Method 5 captures the filterable particulate — what is caught on the heated filter — which is often described as the front half of the train. Condensable particulate that forms as the gas cools is a separate measurement under Method 202, and a rule that says its limit excludes the back half or condensables is drawing exactly that line. Methods 1 through 4 are its standard companions.
Cited by
Provisions in the corpus whose text cites Method 5. Subscribers land on the provision in the regulation reader; visitors see a preview of it (the GP05 sample opens in full).
Common Provisions Regulation
Regulation 6
- II.E.3. — Method 3 for gas analysis to be used when applying Reference Methods 5 and 6;
- II.E.4. — Method 5 for concentration of particulate matter and associated moisture content; and
- III.E.3. — Method 3 for gas analysis to be used when applying reference Methods 5 and 6;
- III.E.4. — Method 5 for concentration of particulate matter and associated moisture content; and
40 CFR Part 60 Subpart IIII
- Table 7 to Subpart IIII of Part 60 — Requirements for Performance Tests for Stationary CI ICE With a Displacement of ≥30 Liters per Cylinder
49 CFR Part 192
The sections marked as regulatory text above are reproduced from the CFR. Everything under ‘EssentialRegs notes’ is our reference copy, not the method. The method as published in the CFR controls.