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US EPA Methods
Introduction to US EPA methods
EPA methods are approved procedures for measuring the presence and concentration of physical, chemical, and biological contaminants. These methods are developed and approved by EPA offices and laboratories for complying with environmental regulations, conducting research, or providing information to the public. EPA methods are constantly updated and revised to reflect the latest scientific knowledge and technological advances.
Click on the plus sign next to each US EPA Method to find more information, valuable links and the parts needed to perform each.
EPA Method 1
Sample and Velocity Traverses for Stationary Sources
Method 1 is designed to aid in the representative measurement of pollutant emissions and/or total volumetric flow rate from a stationary source. A measurement site where the effluent stream is flowing in a known direction is selected, and the cross-section of the stack is divided into a number of equal areas. Traverse points are then located within each of these equal areas.
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EPA Method 2
Determination of Stack Gas Velocity and Volumetric Flow Rate (Type S Pitot Tube)
The average gas velocity in a stack is determined from the gas density and from measurement of the average velocity head with a Type S (Stausscheibe or reverse type) pitot tube.
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EPA Method 3
GAS ANALYSIS FOR THE DETERMINATION OF DRY MOLECULAR WEIGHT
This method is applicable for the determination of CO2 and O2 concentrations and dry molecular weight of a sample from an effluent gas stream of a fossil-fuel combustion process or other process.
A gas sample is extracted from a stack by one of the following methods: (1) single-point, grab sampling; (2) single-point, integrated sampling; or (3) multi-point, integrated sampling. The gas sample is analyzed for percent CO2 and percent O2. For dry molecular weight determination, either an Orsat or a Fyrite analyzer may be used for the analysis.
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EPA Method 4
Determination of Moisture Content in Stack Gases
This method is applicable for the determination of moisture content of stack gas. A gas sample is extracted at a constant rate from the source; moisture is removed from the sample stream and determined either volumetrically or gravimetrically. This method contains two possible procedures: a reference method and an approximation method.
EPA Method 5
Determination of Particulate Matter Emissions from Stationary Sources.
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). The PM mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water.
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EPA Method 6
Determination of Sulfur Dioxide Emissions from Stationary Sources.
A gas sample is extracted from the sampling point in the stack. The SO2 and the sulfur trioxide, including those fractions in any sulfur acid mist, are separated. The SO2 fraction is measured by the barium-thorin titration method.
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EPA Method 7
Determination of Nitrogen Oxide Emissions From Stationary Sources.
A grab sample is collected in an evacuated flask containing a dilute sulfuric acid-hydrogen peroxide absorbing solution, and the nitrogen oxides, except nitrous oxide, are measured colorimetrically using the phenoldisulfonic acid (PDS) procedure.
EPA Method 13A
Total Fluoride – SPADNS Zirconium Lake
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EPA Method 13B
Total Fluoride – Specific Ion Electrode
Particulate by In-Stack Filtration
EPA Method 23
Determination of Polychlorinated Dibenzo-P-Dioxins and Polychlorinated Dibenzofurans From Stationary Sources.
Method 23 identifies and determines the concentration of specific PCDD, PCDF, PCB, and PAH compounds. Gaseous and particulate bound target pollutants are withdrawn from the gas stream isokinetically and collected in the sample probe, on a glass fiber or quartz filter, and on a packed column of adsorbent material. This method is not intended to differentiate between target compounds in particulate or vapor fractions. The target compounds are extracted from the combined sample collection media. Portions of the extract are chromatographically fractionated to remove interferences, separated into individual compounds or simple mixtures by HRGC, and measured with HRMS. This method uses isotopically labeled standards to improve method accuracy and precision through isotope dilution quantitation.
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EPA Method 26A
Determination of Hydrogen Halide and Halogen Emissions from Stationary Sources Isokinetic Method.
Principle. Gaseous and particulate pollutants are withdrawn isokinetically from the source and collected in an optional cyclone, on a filter, and in absorbing solutions. The cyclone collects any liquid droplets and is not necessary if the source emissions do not contain them; however, it is preferable to include the cyclone in the sampling train to protect the filter from any liquid present. The filter collects particulate matter including halide salts but is not routinely recovered or analyzed. Acidic and alkaline absorbing solutions collect the gaseous hydrogen halides and halogens, respectively.
Following sampling of emissions containing liquid droplets, any halides/halogens dissolved in the liquid in the cyclone and on the filter are vaporized to gas and collected in the impingers by pulling conditioned ambient air through the sampling train. The hydrogen halides are solubilized in the acidic solution and form chloride (Cl− ), bromide (Br− ), and fluoride (F− ) ions. The halogens have a very low solubility in the acidic solution and pass through to the alkaline solution where they are hydrolyzed to form a proton (H + ), the halide ion, and the hypohalous acid (HClO or HBrO). Sodium thiosulfate is added to the alkaline solution to assure reaction with the hypohalous acid to form a second halide ion such that 2 halide ions are formed for each molecule of halogen gas. The halide ions in the separate solutions are measured by ion chromatography (IC). If desired, the particulate matter recovered from the filter and the probe is analyzed following the procedures in Method 5.
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EPA Method 29
Determination of Metals Emissions from Stationary Sources.
A stack sample is withdrawn isokinetically from the source, particulate emissions are collected in the probe and on a heated filter, and gaseous emissions are then collected in an aqueous acidic solution of hydrogen peroxide (analyzed for all metals including Hg) and an aqueous acidic solution of potassium permanganate (analyzed only for Hg). The recovered samples are digested, and appropriate fractions are analyzed for Hg by cold vapor atomic absorption spectroscopy (CVAAS) and for Sb, As, Ba, Be, Cd, Cr, Co, Cu, Pb, Mn, Ni, P, Se, Ag, Tl, and Zn by inductively coupled argon plasma emission spectroscopy (ICAP) or atomic absorption spectroscopy (AAS). Graphite furnace atomic absorption spectroscopy (GFAAS) is used for analysis of Sb, As, Cd, Co, Pb, Se, and Tl if these elements require greater analytical sensitivity than can be obtained by ICAP. If one so chooses, AAS may be used for analysis of all listed metals if the resulting in-stack method detection limits meet the goal of the testing program. Similarly, inductively coupled plasma-mass spectroscopy (ICP-MS) may be used for analysis of Sb, As, Ba, Be, Cd, Cr, Co, Cu, Pb, Mn, Ni, Ag, Tl and Zn
EPA Method 25A
Determination of Total Gaseous Organic Concentration Using a Flame Ionization Analyzer
A gas sample is extracted from the source through a heated sample line and glass fiber filter to a flame ionization analyzer (FIA). Results are reported as volume concentration equivalents of the calibration gas or as carbon equivalents.
EPA Method 201A
Determination of PM10 and PM2.5 Emissions from Stationary Sources
To measure PM10 and PM2.5, extract a sample of gas at a predetermined constant flow rate through an in-stack sizing device. The particle-sizing device separates particles with nominal aerodynamic diameters of 10 micrometers and 2.5 micrometers. To minimize variations in the isokinetic sampling conditions, you must establish well-defined limits. After a sample is obtained, remove uncombined water from the particulate, then use gravimetric analysis to determine the particulate mass for each size fraction. The original method, as promulgated in 1990, has been changed by adding a PM2.5 cyclone downstream of the PM10 cyclone. Both cyclones were developed and evaluated as part of a conventional five-stage cascade cyclone train. The addition of a PM2.5 cyclone between the PM10 cyclone and the stack temperature filter in the sampling train supplements the measurement of PM10 with the measurement of PM2.5. Without the addition of the PM2.5cyclone, the filterable particulate portion of the sampling train may be used to measure total and PM10emissions. Likewise, with the exclusion of the PM10 cyclone, the filterable particulate portion of the sampling train may be used to measure total and PM2.5 emissions.
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EPA Method 202
Dry Impinger Method for Determining Condensable Particulate Emissions from Stationary Sources.
The CPM is collected in dry impingers after filterable PM has been collected on a filter maintained as specified in either Method 5, Method 17, or Method 201A. The organic and aqueous fractions of the impingers and an out-of-stack CPM filter are then taken to dryness and weighed. The total of the impinger fractions and the CPM filter represents the CPM. Compared to the version of Method 202 that was promulgated on December 17, 1991, this method eliminates the use of water as the collection media in impingers and includes the addition of a condenser followed by a water dropout impinger immediately after the final in-stack or heated filter. This method also includes the addition of one modified Greenburg Smith impinger (backup impinger) and a CPM filter following the water dropout impinger.
Hexavalent Chromium from Electroplating and Anodizing Operations
Formaldehyde from Mineral Wool and Fiberglass Industries
Extraction of Semivolatile Analytes Collected Using Method 0010 (Modified Method 5 Sampling Train)
Sampling for Selected Aldehyde and Ketone Emissions from Stationary Sources
Determination of Hexavalent Chromium Emissions from Stationary Sources