40 CFR § 61.125 - Test methods and procedures.

---
identifier: "/us/cfr/t40/s61.125"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 61.125 - Test methods and procedures."
title_number: 40
title_name: "Protection of Environment"
section_number: "61.125"
section_name: "Test methods and procedures."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "61"
part_name: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
regulatory_source: "38 FR 8826, Apr. 6, 1973, unless otherwise noted."
cfr_part: "61"
---


# 61.125 Test methods and procedures.

(a) Each owner or operator of a source required to test emissions under § 61.123, unless an equivalent or alternate method has been approved by the Administrator, shall use the following test methods:

(1) Method 1 of appendix A to 40 CFR part 60 shall be used to determine sample and velocity traverses;

(2) Method 2 of appendix A to 40 CFR part 60 shall be used to determine velocity and volumetric flow rate;

(3) Method 3 of appendix A to 40 CFR part 60 shall be used for gas analysis;

(4) Method 5 of appendix A to 40 CFR part 60 shall be used to collect particulate matter containing the polonium-210; and

(5) Method 111 of appendix B to 40 CFR part 61 shall be used to determine the polonium-210 emissions.

[54 FR 51699, Dec. 15, 1989, as amended at 65 FR 62156, Oct. 17, 2000]