Gas Codes & Regulations
CSA B149 series, TSSA authority, technician licensing, appliance approval, and regulatory framework for gas fitting in Ontario.
- Identify the CSA B149 series and its application to gas installations
- Explain TSSA authority and the G2 licensing framework
- Describe appliance approval and compliance requirements
- Apply the regulatory framework for gas fitting in Ontario
Lesson 1
CSA B149 Series & Gas Code Framework
The Foundation of Gas Safety in Canada
The CSA B149 series is the foundation of gas safety regulation in Canada. These standards establish requirements for the installation and maintenance of natural gas and propane equipment. For the G2 Gas Technician exam, two documents are critical:
CSA B149.1 - the Natural Gas and Propane Installation Code - covers all aspects of gas piping, appliance installation, venting, and commissioning. It is the primary code reference for the G2 exam. The 2025 edition (B149.1:25) comes into force in March 2026 and introduces updated requirements for hydrogen-natural gas blends, press-connect fittings, and CSST bonding aligned with the Canadian Electrical Code (CEC Part I).
CSA B149.2 - the Propane Storage and Handling Code - covers propane tank installation, storage requirements, and safety distances. The 2025 edition (B149.2:25) also comes into force in March 2026.
Code Adoption
Like building codes, the CSA B149 series is a national standard that provinces adopt. In Ontario, the Technical Standards and Safety Authority (TSSA) administers and enforces the gas code through the Technical Standards and Safety Act and Ontario Regulation 212/01 (Gaseous Fuels).
2025 Edition in Force March 2026
The CSA B149.1:25 and B149.2:25 editions come into force in March 2026. Key updates include: provisions for hydrogen-natural gas blends (including appliance rating plate requirements and odorization), permission for certified press-connect fittings up to NPS 4, and updated CSST bonding requirements aligned with CEC Part I. For the G2 exam, verify which edition your jurisdiction has adopted - exam content follows the adopted code.
CSA B149.1:25 - Key Updates
Hydrogen-natural gas blend provisions:
The 2025 edition introduces requirements for the expanding deployment of hydrogen-natural gas (H2NG) blended fuel systems. Key provisions include:
- Appliances operating on H2NG blends must have their rating plate updated to indicate the approved blend percentage (e.g., "approved for up to 5% hydrogen blend")
- Odorization requirements for hydrogen blends - odorant injection rates must be adjusted to provide equivalent olfactory warning for the blend composition, since hydrogen itself has no odor
- Gas piping system materials must be verified for hydrogen embrittlement resistance at the blend percentages being used
- Technicians must verify appliance compatibility before connecting to a hydrogen-blended supply
Press-connect fittings:
CSA B149.1:25 now permits certified press-connect fittings for gas piping up to NPS 4 (nominal pipe size 4 inches). Press-connect fittings must bear a certification mark confirming compliance with applicable CSA standards for gas service. This is an expansion from the previous restriction that limited press-connect use to specific smaller sizes.
CSST bonding updates:
The updated code aligns CSST bonding requirements with the Canadian Electrical Code (CEC Part I), which specifies the bonding conductor requirements, connection methods, and grounding electrode specifications. The fundamental requirement - that all CSST must be bonded to the building grounding electrode system - remains, but the updated language references CEC Part I directly to ensure coordination between gas and electrical trades.
CSA B149.1:25 is the current primary gas installation code (in force March 2026). Key updates include: hydrogen-natural gas blend provisions (rating plate and odorization requirements), certified press-connect fittings now permitted up to NPS 4, and CSST bonding requirements aligned with CEC Part I. TSSA is the regulatory authority in Ontario.