40 CFR § 63.885 - Test methods and procedures.

---
identifier: "/us/cfr/t40/s63.885"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 63.885 - Test methods and procedures."
title_number: 40
title_name: "Protection of Environment"
section_number: "63.885"
section_name: "Test methods and procedures."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "63"
part_name: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
regulatory_source: "57 FR 61992, Dec. 29, 1992, unless otherwise noted."
cfr_part: "63"
---


# 63.885 Test methods and procedures.

(a) You must use the following methods to determine compliance with the applicable emission limits:

(1) Method 1 at 40 CFR part 60, appendix A-1 for the selection of the sampling port location and number of sampling ports;

(2) Method 2 at 40 CFR part 60, appendix A-1 for volumetric flow rate;

(3) Method 3 or 3A (40 CFR part 60, appendix A-2) for oxygen and carbon dioxide for diluent measurements needed to correct the concentration measurements to a standard basis;

(4) Method 4 at 40 CFR part 60, appendix A-4 for moisture content of the stack gas;

(5) Method 29 (40 CFR part 60, appendix A-8) for the concentration of chromium compounds. Each run must consist of a minimum sample volume of two dry standard cubic meters.

(6) An alternative method, subject to approval by the Administrator.

(b) Each performance test must consist of three runs. You must use the average of the three runs in the applicable equation for determining compliance.