All compressed gases are hazardous because of the high pressures
they are stored at. This hazard is in addition to hazards associated
with the inherent nature of the substance.
The compressed gas can be released deliberately by opening the
cylinder valve, or accidentally from a broken or leaking valve or
from a safety device. Even at a relatively low pressure, gas can
flow rapidly from an open or leaking cylinder. Damaged cylinders
have the potential to become uncontrolled rockets or pinwheels,
causing severe injury and damage. This can happen when an unsecured
or uncapped cylinder is knocked over causing the cylinder valve to
break and high-pressure gas to escape rapidly.
This web page contains information to help people comply with the requirements of the Hazardous Substances and New Organisms (HSNO) Act as they relate to compressed gases. It provides links to information and guidance material for this purpose.
Hazardous Substances (Compressed Gases) Regulations 2004
These regulations, made under the Hazardous Substances and New Organisms Act 1996, came into effect on 26 March 2004, and contain provisions for:- Approving standards which compressed gas containers (including cylinders) must comply with, and
- Certifying the design of, pre-commissioning of, and import clearance of compressed gas containers, and
- Fire extinguishers, and
- Restrictions on aerosols and non refillable containers, including standards which must be complied with, and
- Restrictions on cylinder fittings, including valves and regulators, and
- Labelling and marking, and
- Periodic testing of cylinders and fittings, and
- Restrictions on charging compressed gas containers, and
- Restrictions on persons able to charge compressed gas containers, and
- Emergency management, including emergency response plans, and
- Requirement to establish registers for cylinders, fittings and specifications.
These regulations are available at: www.legislation.govt.nz.
This web page is not intended to provide an outline of these regulations. You are encouraged to download a copy of the regulations from the above site.
Group Standards for Compressed Gas Mixtures
A group standard is an approval for a group of hazardous substances under Part 6A of the HSNO Act and streamlines the transfer of substances previously notified under the Toxic Substances Act 1979 (NOTS) into the HSNO regime. There are a series of group standards for mixtures of compressed gases and these can be accessed at:
http://www.ermanz.govt.nz/hs/groupstandards/standards/gases.html
Substances encompassed by the Group Standards for Compressed Gas Mixtures must comply with the relevant parts of the Hazardous Substances (Compressed Gases) Regulations 2004.
Approved practice guide – Guide to Gas Cylinders
ERMA New Zealand has prepared the approved practice guide APG 4-1 Guide to Gas Cylinders which provides guidance on many aspects of cylinder importation, use, charging and inspection. This is a useful document for those working in the compressed gas cylinder industry.
A copy of this document is available at: http://www.ermanz.govt.nz/hs/compliance/codesofpractice.html
Recognition of cylinders approved for use in New Zealand
All cylinders approved for charging in New Zealand are required to be stamped with a register number. This is normally stamped at the time of manufacture of the cylinder. The register number is in the form of LABxxxx or, in the case of special cylinders, LABSPxxx
Special cylinders
From time to time, individual cylinders are brought into New Zealand. These may come in as personal effects from people emigrating to New Zealand, or as diving gear on board visiting yachts, etc. These cylinders may not be filled in New Zealand unless they are approved for this purpose.
An application for a special cylinder is made as an Application
for Waiver of Pre-commissioning Certificate Requirements under
Regulation 21 Hazardous Substances (Compressed Gases) Regulations
2004. An application for approval of a special cylinder is available
at:
http://www.ermanz.govt.nz/resources/hs-pubs_other2.html
Registers
ERMA New Zealand maintains the following registers related to compressed gas containers:
- register of cylinders that are approved for filling in New Zealand;
- register of special cylinders that are approved for filling in New Zealand;
- register of fittings approved for use in New Zealand;
- register of cylinder design standards approved for use in New Zealand;
- register of marks of cylinder manufacturers;
- register of recognised inspection agencies; and
- register of test certifiers approved to issue test certificates
These registers are available at: http://www.ermanz.govt.nz/search/index.html#other
Filling compressed gas containers
People filling compressed gas containers, including cylinders, must be trained and must hold an Approved Filler Test Certificate. Training to become an approved filler can be carried out by a test certifier and, in the case of LPG, by a site trainer under the LPG Association Cylinder Filling Training Programme protocol. In all cases the test certificate must be issued by a test certifier.
For more information on approved fillers go to: http://www.ermanz.govt.nz/hs/compliance/cg-cylinders.html
Further information is available in section 7 of the approved
practice guide APG 4-1 Guide to Gas Cylinders, which is available
at:
http://www.ermanz.govt.nz/hs/compliance/codesofpractice.html
Certification of cylinders
All cylinders imported into New Zealand for filling with compressed gases are required to be certified. The three predominant steps include:
- Design verification certification.
- Pre-commissioning certification.
- Import clearance certification.
These are undertaken by test certifiers approved for each type of
certification. A register of approved test certifiers is located at:
http://www.ermanz.govt.nz/Find/TestCertifierSearch.aspx
Fire extinguishers (excluding CO2 extinguishers) are to be certified by obtaining a fire extinguisher registration number. Refer to the following link for an explanation of this.
http://www.ermanz.govt.nz/resources/publications/pdfs/decision_paths/ER-PR-03-22%2002-09_5.3.pdf
Guidance on the process for certifying cylinders and importing them into New Zealand is available at:
Process_for_Importing_Gas_Cylinders
Liquefied gases (including LPG)
Liquefied gases are gases which can become liquids at normal temperatures when they are inside cylinders under pressure. They exist inside the cylinder in a liquid-vapour balance, or equilibrium. Initially the cylinder is almost full of liquid, and gas fills the space above the liquid. As gas is removed from the cylinder, enough liquid evaporates to replace it, keeping the pressure in the cylinder constant. LPG (liquefied petroleum gas), propane, anhydrous ammonia, chlorine, nitrous oxide and carbon dioxide are examples of liquefied gases.
Information specific to LPG can be found on the ERMA New Zealand website at:
http://www.ermanz.govt.nz/hs/compliance/guides/lpgusers.html
Further information is available in the Compliance Guide at:
http://www.ermanz.govt.nz/resources/hs-pubs_compliance.html
Hazardous substances
Many compressed gases are hazardous substances in their own right. Under the HSNO Act they have hazard classifications and attract controls specific to them. These controls must be applied e.g. approved handler, location test certificate, etc. For information on HSNO compliance, refer to: