The Gas (Safety & Measurement) Regulations 2010 introduced on 4 May 2010 require that all gas appliances and fittings are capable of operating safely when installed correctly and used for their intended purpose. Part 2 (Regulations 9 to 15) sets out a general requirement for safety and what is deemed to be unsafe.
Regulation 43 sets out the specific safety requirements for the installation of gas appliances and fittings. The regulation requires that every person who installs a gas installation must install it in accordance with NZS 5261: Gas installation: 2003.
NZS 5261 is divided into three parts. Compliance with the first part, which sets out the essential safety requirements, is mandatory. The remaining two parts are a means of compliance with Part 1. Parts 2 and 3 are intended for fixed gas installations that are in buildings.
The Regulations state that the importer of an installation such as a caravan must ensure that it meets the requirements of Part 1 of NZS 5261.
The Regulations state that for caravans and boats, compliance with NZS 5428: LPG Installations for non-propulsive purposes in caravans and boats: 2006 is deemed a means of complying with the requirements.
Regulation 53 requires that "…every person who manufactures, imports, sells or offers for sale, hires out, leases out, or installs a gas appliance or fittings must take all practicable steps to ensure that the gas appliance or fittings is safe."
The Regulations introduce a new requirement that appliances are either certified or endorsed in accordance with the Regulations. After 4 May 2012an appliance will be considered to be unsafe unless it has been certified or endorsed.
To allow the industry time to adapt to these new requirements the appliance safety regime of the Gas Regulations 1993 will be considered to be meeting these new requirements until 4 May 2012. Details on the old regime may be found here.
Regulations 54 to 59 describe the certification and endorsement regimes. In general terms, appliances supplied in bulk must be certified to either NZS 5262 or to the European or Australian certification regimes. Small production appliances or specialised gas appliances must be endorsed by an approved practitioner approved by Energy Safety.
Gas appliances must have certain data markings on them to provide information for their safe installation. This is specified in Regulation 71.
Appliances subject to the certification regime must have a supplier declaration and a gas safety compliance label. (The supplier declaration scheme is detailed below). There are also responsibilities for those repairing, modifying, adjusting, and hiring gas appliances and fittings as set out in regulations 74 and 75. Regulations 44 to 49 require that for most types of gasfitting, the installer must certify the installation as being compliant with the regulations.
There are substantial penalties for non-compliance. Failing to comply with the Regulations is an offence which on summary conviction is liable to a fine of up to $10,000 for an individual or $50, 000 for a body corporate depending on the grade of offence.
The Regulations also have infringement notices where the fees are up to $1,000 for an individual or $3,000 for a body corporate depending on the grade of offence.

Reference: http://www.energysafety.govt.nz