eCFR Reference Browser

---

title: "40 CFR §90.117"

source: "https://www.ecfr.gov/current/title-40/section-90.117"

title_number: "40"

volume_number: "22"

chapter_number: "Unknown"

subchapter_code: "C"

subchapter_subject: "AIR PROGRAMS (CONTINUED)"

part_code: "90"

part_subject: "CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS"

subpart_code: "B"

subpart_subject: "Emission Standards and Certification Provisions"

section_number: "90.117"

section_subject: "Certification procedure—test engine selection."

cfr_reference: "40 CFR 90.117"

title_name: "Title 40"

title_subject: "Protection of Environment"

parts_covered: "Parts 87 to 95"

revised_date: "Revised as of July 1, 2017"

publication_date: "As of July 1, 2017"

contains_description: "Containing a codification of documents of general applicability and future effect"

publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"

---

(a)For Phase 1 engines, the manufacturer must select, from each engine family, a test engine that the manufacturer determines to be most likely to exceed the emission standard. For Phase 2 engines, the manufacturer must select, from each engine family, a test engine of a configuration that the manufacturer determines to be most likely to exceed the HC + NOX (NMHC + NOX) Family Emission Limit (FEL), or HC + NOX (NMHC + NOX) standard if no FEL is applicable.

(b)The test engine must be constructed to be representative of production engines.

§90.117 - Certification procedure—test engine selection.