Ask a gas safety officer: Why does gas piping need to be bonded?
Electrical bonding is the practice of intentionally electrically connecting all exposed metallic items not designed to carry electricity in a room or building as protection from electric shock. If a failure of electrical insulation occurs, all bonded metal objects in the room will have substantially the same electrical potential, so that an occupant of the room cannot touch two objects with significantly different potentials. Even if the connection to a distant earth ground is lost, the occupant will be protected from dangerous potential differences.
Gas piping systems are required to be bonded by the B149.1 Natural Gas and Propane Installation code, as well as the C22.1 Canadian Electrical code (adopted as BC Electrical Code). The bonding is intended to not only protect the occupants from a potential electrical difference between two metallic surfaces, but also to protect the piping. As shown in the photo above, arcing created by a potential difference in a fault situation can damage piping or tubing systems creating a possible uncontrolled escape of gas from the system.