Small Off-Road Engine or Equipment Regulatory and Certification Documents

This page provides a list of the Manufacturers Advisory Correspondence (MACs), mailouts, correspondence, regulation, test procedures, and guidelines applicable to Small Off-Road Engines or Equipment less than or equal to 19 kilowatts (25 horsepower), and is primarily for the interest and needs of manufacturers and others that are required to obtain certification from CARB. In addition, the engine certification database and Executive Orders can be accessed below. This page also contains a link to the component Executive Order list, which may be used for evaporative certification.

Subscribe to the Mobile Source Mailouts and MAC topic to be notified when a new Mobile Source Mailout or MAC has been posted.

Updates

On April 30, 2019, CARB conducted a public workshop to discuss the proposed adoption of a schedule of fees for mobile source certification and compliance.

Regulations and Test Procedures

Regulations

Exhaust Emission Regulations

Amendments to the Small Off-Road Engine Exhaust Emission Regulations, California Code of Regulations, Title 13, Division 3, Chapter 9. Off-Road Vehicles and Engines Pollution Control Devices, Article 1. Small Off-Road Engines (amended January 1, 2023)
Amendments to the Exhaust Emission Regulations - Sections 2403, 2404, and 2407 (adopted October 25, 2012)
Amendments to the Exhaust Emission Regulations - Sections 2401, 2403-2406, 2408, 2409 and Adopted Section 2408.1 (adopted February 24, 2010, and corrected March 29, 2010)
Exhaust Emission Regulation Order (adopted July 26, 2004)

Evaporative Emission Regulations

Amendments to the Small Off-Road Engine Evaporative Emission Regulations, California Code of Regulations, Title 13, Division 3, Chapter 15. Additional Off-Road Vehicles and Engines Pollution Control Requirements, Article 1. Evaporative Emission Requirements for Off-Road Equipment (amended January 1, 2023)
Amended Evaporative Emission Regulation Order- Sections 2750 - 2774 (amended May 6, 2019)
Amended Evaporative Emission Regulation Order (amended September 18, 2017)
Final Evaporative Emission Regulation Order (adopted July 26, 2004)

Preempt Equipment

Test Procedures

Exhaust Emission Test Procedures

Model Year 2013 and Later

Amendments to the California Exhaust Emission Standards and Test Procedures for New 2013 and Later Small Off-Road Engines; Engine-Testing Procedures (Part 1054) (amended January 1, 2023)
California Exhaust Emission Standards and Test Procedures for New 2013 and Later Small Off-Road Engines (Part 1054) (adopted October 25, 2012)
Amendments to the California Exhaust Emission Standards and Test Procedures for New 2013 and Later Small Off-Road Engines; Engine-Testing Procedures (Part 1065) (amended January 1, 2023)
California Exhaust Emission Standards and Test Procedures for New 2013 and Later Small Off-Road Engines (Part 1065) (adopted October 25, 2012)

Model Year 2005 - 2012

California Exhaust Emission Standards and Test Procedures for 2005-2012 Small Off-Road Engines (adopted July 26, 2004)
Amendments to the California Exhaust Emission Standards and Test Procedures for 2005-2012 Small Off-Road Engines (amended February 24, 2010)
Amendments to the California Exhaust Emission Standards and Test Procedures for 2005-2012 Small Off-Road Engines (amended October 25, 2012)

Model Year 1995 - 2004

Evaporative Emission Test Procedures

Alternative Evaporative Emission Test Procedures

For questions regarding approval of an alternative test procedure, contact Michele Dunlop at (916) 323-8971

SORE Fact Sheet & FAQ

Manufacturers Advisory Correspondence

MAC Number	Subject
MAC 05-05	Evaporative Emission Requirements for Vehicles with On-Board Generators
MAC 01-01	Optional Use of the Federal Engine Test Cycle Speed and Load Specifications for Exhaust Emission Testing of Spark-Ignition Small Off-Road Engines
MAC 96-06	Modified Test Procedures for Integrated Generator Sets (Gensets)
MAC 95-02	Utility and Lawn and Garden Equipment Engine (ULGE) Streamlined Certification Procedures
MAC 94-08	Certification of One-Wheeled Lawn Edger Equipment Engines
MAC 94-05	Emission Control Part Identification for Utility and Lawn and Garden Equipment Engines (ULGEs)
MAC 92-06	Small-Engine Certification Procedures

Mobile Source Mailouts

Mailout Number	Subject
ECARS 19-04	Guidance for Manufacturers Regarding the Submittal of Certification Applications and Bond Worksheet for Small and Large (< 1L) Spark-Ignited Evaporative Families for 2020 and Later Model Years Attachment 1: Bond Requirements Guidance for Small Spark-Ignited Off-Road Equipment Attachment 2: Bond Worksheet for Small SI Evaporative Certification Attachment 3: Evaporative Certification Form for < 80 cc Attachment 4: Evaporative Certification Form for > 80 cc
ECARS 18-05	Format for Annual Production Volume Reports for Small Spark-Ignited Evaporative Families Attachment 1: Guidance to Manufacturers Regarding Submittal of Production Volume Reports for Small Spark-Ignited Evaporative Families Table 1: Format for the Production Volume Report
ML 15-01	Small Off-Road Engine Evaporative Certification Changes and Fuel Hose Requirements
ECARS 15-07	Streamlined Certification Process For Carryover And Partial Carryover Certification Applications
MSO 07-03	New Requirement to Report Carbon Dioxide Emissions from 2008 and Subsequent Model Year California Certified Vehicles and Engines
MSO 05-05	Public Workshop to Present New Procedures and Requirements for Submitting Mobile Source Emissions Certification Support Documents Electronically
MSO 00-14	Format for Manufacturer Certification and Production Emission Reduction Credit Program for New Engine End-of-Year and Final Reports Model Year 2015 and Later (updated March 4, 2015) Excel Templates Attachment 1 Attachments 2, 3, 5, 6, 8, 9 Model Year 2007 - 2014 Excel Templates Access Template Attachment 1 Attachments 2, 3, 5, 6, 8, 9 Attachments 4 and 7 Model Year 2006 and Earlier Excel Templates Access Template Attachment 1 Attachments 2, 3, 5, 6, 8, 9 Attachments 4 and 7
MSO 99-08	Certification of 2000 Model Year (MY) and Later Small Off-Road Engines (SORES), and Attachment B (data)
MSO 99-07	Format for Production Line Testing Quarterly Reports for 2000 Model Year and Later Small Off-Road Engine Families Attachment 1 - Overview of attachments and database structure Attachments 2 through 10, not 6 or Attachments 2 and 3 and Attachment 4 and Attachments 5, 7-10 Attachment 6 (data) The corresponding templates for the four CARB-specified file formats and the Access hard copy formats, referenced in MSO 99-07, are listed below: Engine Family Information File Engine Family Data Per Quarter File Individual Engine Test Data Per Quarter Combined Quarters Engine Family File Small Off-Road Engine (updated February 28, 2018)
MSO 96-30	Tamper-Resistance Requirements for Gaseous-Fueled Engines
MSO 95-45	Clarification of Certification Requirements for Utility and Lawn and Garden Equipment Engines (ULGEs) as Detailed in Air Resources Board Mail-out 95-30
MSO 95-30	Clarification of Certification Procedures for Utility and Lawn and Garden Equipment Engines (ULGEs)

Correspondence

Reference Number	Subject
Reference No. NSC-2013-262	CARB October 14, 2013 Letter to Outdoor Power Equipment Institute (OPEI) on Greenhouse Gas Emissions Calculation Factors for 2014 and Later Model-Year Small Spark-Ignition Engines Less than 80 cc CARB April 13, 2005 Response Letter to Outdoor Power Equipment Institute (OPEI) request for enforcement relief
Reference No. NSC-2004-025	OPEI's July 1, 2004 Letter to the California Air Resources Board (CARB) on Certification of 2005 Model-Year Handheld Lawn and Garden Products
Reference No. C-2000-343	California Air Resources Board (CARB) June 5, 2000 Letter to Portable Power Equipment Manufacturers Association (PPEMA) on Alternative Duty Cycles for the Certification of Small Off-Road Engines (SOREs) Below 65 cubic centimeters (cc) in Displacement PPEMA March 8, 2000 Letter to CARB on Alternative Duty Cycles for SOREs Below 65 cc in Displacement
Reference No. C-99-313	California Air Resources Board (CARB) May 10, 1999 Letter to Engine Manufacturers Association (EMA) on Deterioration Factor (DF) Test Procedure EMA April 26, 1999 Letter to CARB on EMA Proposal for an Acceptable DF Test Procedure

Guidelines

Certification Application Forms
- SORE Exhaust Certification Application Form for 2024 and Later Model Years (December 5, 2023)
- SORE Evaporative Certification Application Form for 2024 and Later Model Years (December 5, 2023)
- Zero-Emission Equipment Family Certification Application Form for 2023 and Later Model Years (December 5, 2023)
- Zero-Emission Generator Family Certification Application Form for 2023 and Later Model Years (December 5, 2023)
SORE Evaporative Model Summary Excel Template for 2024 and Later Model Years (February 8, 2024)
SORE Exhaust Model Summary Excel Template (updated August 19, 2021)
Supplemental SSIE Exhaust Application Required for 2013 and Later Small Off-Road Engines (December 16, 2011 SSIE Board Hearing Changes)
- Supplemental SSIE Exhaust Application Instructions (updated March 26, 2013)
- Supplemental SSIE Exhaust Application Form (updated March 26, 2013)
Development of Deterioration Factors for Small Off-Road Engines
Engine Sampling Plan Requirements (updated November 15, 2002)
Procedures for Utilization of Auxiliary Engine Cooling
Evaporative Emission Certification Procedures
Guidelines for Evaporative Certification of 2006 and Later Small Off-Road Engine/Equipment (updated January 10, 2007)
- Model Year 2020 and Later
  - Evaporative Certification Form for < 80 cc (updated May 30, 2019)
    - SORE Evaporative < 80 cc Model Summary Excel Template (updated August 19, 2021)
  - Evaporative Certification Form for > 80 cc (updated May 30, 2019)
    - SORE Evaporative > 80 cc Model Summary Excel Template (updated August 19, 2021)
- Model Year 2019 and Earlier
  - Evaporative Certification Form for < 80 cc
  - Evaporative Certification Form for > 80 cc (updated November 10, 2015)

Presentations

Small Spark-Ignited Engine Evaporative Certification Workshop Presentation (October 4, 2019)
- Presentation
SORE/HMC/OHRV Certification and Compliance Workshop Presentation (updated November 9, 2015)
- Original Presentation
- Expanded SORE-only Presentation

Engine Certification Database

View the Certification Database and the Executive Orders for Spark-Ignition Small Off-Road Engines.

Component Executive Orders

View the Component Executive Orders for evaporative certification of Spark-Ignition Small Off-Road Engines or Equipment.

Document Management System (DMS)

View the guidelines regarding the electronic Document Management System used to submit certification applications and supporting documents.

For more information on Small Spark-Ignition Off-Road Engine or Equipment certification procedures, contact:

Exhaust - Janie Han at (951) 542-3191
Evaporative - Sophia Mahmood at (951) 542-3277