You will need to comply with this standard if you work as a gas fitter or plumber.
The standard specifies the uniform minimum requirements for the design, construction and safe operation of Type B appliances that are intended for use with town gas, natural gas, simulated natural gas, liquefied petroleum gas and tempered liquefied petroleum gas or any combination of these gases either together or with other fuels.
Type B appliances are defined as an appliance with a gas consumption of more than 10MJ per hour.