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Air Emission Measurement Center (EMC)

  • Emission Measurement Center

    The EPA hub for stationary source air emissions test methods and procedures.

NOTICE: It has come to our attention that one of the two providers of audit samples has ceased manufacturing samples for the stationary source audit program.  The general provisions to 40 CFR Parts 60 and 63 (see §60.8(g)(1) and §63.7(c)(2)(iii)(A)) require that the owner or operator obtain audit samples if the audit samples are  “commercially available” and have defined “commercially available” as two or more independent accredited audit sample providers (AASP) to have blind audit samples available for purchase. Since there are no longer two providers, the requirement to obtain these audit samples is no longer in effect until such time as another independent AASP has audit samples available for purchase.

When there are two or more AASP with audit samples available for purchase, we will update this webpage with the name or names of the providers and audit sample(s) available for purchase. At that time, this information must be listed on the EMC website for 60 days before audits are required again.

The Air Emission Measurement Center (EMC) provides information on test methods for measuring pollutants from smokestacks and other industrial sources. This website compiles the test methods available for emission measurement. Contact EMC staff for technical assistance in the use and application of the methods.

Recent Updates
  • November 2024:
    • Condensable PM Adjustment for Ammonium Sulfate Formation in M202 Test Results
      • November 21, 2024 Memo Discussing the Condensable PM Adjustment for Ammonium Sulfate Formation in M202 Test Results (pdf) (214.74 KB)
      • OTM-59, Method for the Correction of Residual Ammonia in Condensable Particulate Matter Samples Collected according to Method 202 (pdf) (440.87 KB)
  • March 2024:
    • EPA issues updated calibration gas usage memo
      • Accepted Use of Protocol Gases and the Gases that are Recognized for Regulatory Use (pdf) (265.72 KB)
      • Summary of actions (pdf) (203.7 KB)
    • EPA Proposes revisions to EPA Method 320 – Measurement of Vapor Phase Organic and Inorganic Emissions by Extractive Fourier Transform Infrared (FTIR) Spectroscopy 
      • Fact sheet for EPA Method 320 – Measurement of Vapor Phase Organic and Inorganic Emissions by Extractive Fourier Transform Infrared (FTIR) Spectroscopy (pdf) (241.93 KB)
      • Method 320 Proposal - Federal Register Notice - March 1, 2024 (pdf) (744.96 KB)
  • February 2024:
    • EPA Announces a Webinar for Oil & Gas Advanced Methane Technology Alternative Test Method Program
  • January 2024:
    • EPA Announces Stakeholder Meetings for Revisions to Methods 325B
  • December 2023
    • EPA Releases OTM 50 - Sampling and Analysis of Volatile Fluorinated Compounds from Stationary Sources Using Passivated Stainless-Steel Canisters
  • November 2023:
    • $8.8 Million in Funding Awarded to Measure Pollution from Wood Heaters as Part of Investing in America Agenda

  • April 2023:
    • Proposed Method 327 Fugitive and Area Source Measurement of Selected Volatile Organic Hazardous Air Pollutants Using Specially Prepared Canisters (pdf) (784.32 KB)
    • Proposed Performance Specification 19 - Performance Specifications and Test Procedures for Ethylene Oxide (EtO) Continuous Monitoring Systems
    • Proposed Performance Specification 19 (PS-19) Appendix A - Standard Addition Procedures

    • Proposed Performance Specification 19 Appendix B - Preparation and Certification of Ethylene Oxide Gas Standards

    • Proposed Procedure 7 Quality Assurance Requirements for Gaseous Ethylene Oxide (EtO) Continuous Monitoring Systems Used for Compliance Determination

  • March 2023: Final Rule Testing Provisions for Air Emission Sources
  • March  2023: Final Rule Revisions to EPA Method 23

Test Methods

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Monitoring

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  • EMC Methods Support Directory

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Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 16, 2025
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