Code of Federal Regulations > Title 40 > Chapter I > Part 1054 > Subpart I > Appendix Appendix A - Appendix A to Part 1054

Regulations last checked for updates: Jan 18, 2025

Title 40 - Protection of Environment last revised: Dec 30, 2025

Appendix Appendix A - Appendix A to Part 1054—Summary of Previous Emission Standards

The following standards, which EPA originally adopted under 40 CFR part 90, apply to nonroad spark-ignition engines produced before the model years specified in § 1054.1:

(a) Handheld engines. (1) Phase 1 standards apply for handheld engines as summarized in the following table starting with model year 1997:

Table 1 to Appendix I—Phase 1 Emission Standards for Handheld Engines

[g/kW-hr] ^a

Engine displacement class	HC	NOX	CO
Class III	295	5.36	805
Class IV	241	5.36	805
Class V	161	5.36	603

^a Phase 1 standards are based on testing with new engines only.

(2) Phase 2 standards apply for handheld engines as summarized in the following table starting with model year 2002 for Class III and Class IV, and starting in model year 2004 for Class V:

Table 2 to Appendix I—Phase 2 Emission Standards for Handheld Engines

[g/kW-hr]

Engine displacement class	HC + NOX	CO
Class III	^a 50	805
Class IV	^b 50	805
Class V	^c 72	603

^a Class III engines had alternate HC+NOX standards of 238, 175, and 113 for model years 2002, 2003, and 2004, respectively.

^b Class IV engines had alternate HC+NOX standards of 196, 148, and 99 for model years 2002, 2003, and 2004, respectively.

^c Class V engines had alternate HC+NOX standards of 143, 119, and 96 for model years 2004, 2005, and 2006, respectively.

(b) Nonhandheld engines. (1) Phase 1 standards apply for nonhandheld engines as summarized in the following table starting with model year 1997:

Table 3 to Appendix I—Phase 1 Emission Standards for Nonhandheld Engines

[g/kW-hr] ^a

Engine displacement class	HC + NOX	CO
Class I	16.1	519
Class II	13.4	519

^a Phase 1 standards are based on testing with new engines only.

(2) Phase 2 standards apply for nonhandheld engines as summarized in the following table starting with model year 2001 (except as noted for Class I engines):

Table 4 to Appendix I—Phase 2 Emission Standards for Nonhandheld Engines

[g/kW-hr]

Engine displacement class	HC + NOX	NMHC + NOX	CO
Class I-A	50		610
Class I-B	40	37	610
Class I ^a	16.1	14.8	610
Class II ^b	12.1	11.3	610

^a The Phase 2 standards for Class I engines apply for new engines produced starting August 1, 2007, and for any engines belonging to an engine model whose original production date was on or after August 1, 2003.

^b Class II engines had alternate HC + NOX standards of 18.0, 16.6, 15.0, 13.6 and alternate NMHC + NOX standards of 16.7, 15.3, 14.0, 12.7 for model years 2001 through 2004, respectively.

(3) Note that engines subject to Phase 1 standards were not subject to useful life, deterioration factor, production-line testing, or in-use testing provisions. In addition, engines subject to Phase 1 standards and engines subject to Phase 2 standards were both not subject to the following provisions:

(i) Evaporative emission standards as specified in §§ 1054.110 and 1054.112.

(ii) Altitude adjustments as specified in § 1054.115(c).

(iii) Warranty assurance provisions as specified in § 1054.120(f).

(iv) Emission-related installation instructions as specified in § 1054.130.

(v) Bonding requirements as specified in § 1054.690.

[86 FR 34526, June 29, 2021. Redesignated and amended at 88 FR 4668, Jan. 24, 2023]

authority: 42 U.S.C. 7401-7671q.

source: 73 FR 59259, Oct. 8, 2008, unless otherwise noted.