There are three levels of risk classification for gasfitting. These are low-risk, high-risk and general. There are more requirements for certification for high-risk and general gasfitting than there are for low-risk gasfitting.

Regulation 5A defines the three categories of gasfitting work as low-risk, high-risk, and general. This categorisation focuses resources and attention where they are more likely to be needed to achieve compliance and safety.

The risk-based approach to certification means that there are fewer requirements for low-risk gasfitting than there are for general or high-risk gasfitting.

Low-risk gasfitting

Low-risk gasfitting is any of the following:

• Replacement of a gas appliance with an equivalent gas appliance, except in a caravan or boat with sleeping quarters, provided the work does not involve:
• the repositioning of pipework or flue, or
• a change in the installation pressure, gas type, ventilation, energy consumption, or operation of the installation.

This is sometimes referred to as ‘like for like’ gasfitting

• The maintenance of fittings and appliances other than repairs following a notifiable accident
• The replacement of instrumentation and related controls, but only if the work does not result in the repositioning or disturbance of other pipework
• The setting of safety devices, combustion conditions, and controls that are not designed to be adjusted by a consumer or gas refueller
• Temporary gasfitting for experimental, testing, demonstration, teaching, or research purposes in a gas engineering workshop, manufacturing facility, gas test facility, laboratory, hospital, research project, or teaching institution.
• Gasfiting for the purposes of testing in accordance with NZS 5255 or NZS 5266.

High-risk gasfitting

High-risk gasfitting is work which is not low-risk gasfitting and meets one or more of the high-risk criteria. Specifically, high-risk gasfitting is any of the following (provided it is not already assessed as low-risk):

• Addition or alteration to an existing installation
• Work not carried out in accordance with the means of compliance in  applicable AS/NZS 5601standard  
• Work on an installation that includes gas pressure-raising equipment
• Repair work following a notifiable accident
• Work in domestic premises where the maximum operating pressure is more than 7 kPa for natural gas or more than 14 kPa for LPG
• Work in a building of more than three storeys which contains three or more separate dwellings
• Work done to AS/NZS 5601.1 where the supply pressure to the installation is greater than 200 kPa
• Work done to AS/NZS 5601.2 where the supply pressure to the installation is greater than 3 kPa
• Work done within 20 metres of a hazardous area
• Work done in a building in which air pressure is controlled by a mechanical ventilation system
• Work done in a place where combustion air may be varied by mechanical means
• Work done in a caravan or boat that contains sleeping accommodation.

General gasfitting

General gasfitting is gasfitting that is not categorised as low-risk or high-risk work.

Example of gasfitting risk classification

To see how these risk categories are applied here is an example using a gas hob connected to a 9 kg cylinder, working through the risk criteria in the order they should be applied:

• If the gasfitting work is replacement of the appliance that does not require repositioning of pipework or a change in the installation pressure, gas type, ventilation, energy consumption, or operation, and provided it is not in a caravan or boat with sleeping quarters, it is low-risk gasfitting
• If the gas hob is installed in a caravan or boat with sleeping quarters it is high-risk gasfitting
• If the gas hob is installed as part of an addition or alteration to an existing installation it is high-risk gasfitting
• If it is a new installation of a gas hob, it is general gasfitting.