How to Store and Handle Liquified Petroleum Gas (LP Gas): A Complete Guide

LPG - short for Liquified Petroleum Gas or Liquid Petroleum Gas - and also called LP Gas - is actually a term used to describe two flammable hydrocarbon Natural Gas Liquids (NGLs): propane (C3H8) and butane (C4H10), or even a mixture of the two.

In Australia, LPG is almost exclusively propane, whereas overseas it can be butane, propane or a mixture of both. LPG is also referred to as bottled gas, BBQ gas and camping gas. LPG is not the same as Natural Gas, which is primarily methane (CH4).

Like many other fossil fuels, LPG-propane is extracted from gas and oil wells. Around 60% of LPG-propane is derived from natural gas processing in LPG extraction plants, with the remaining 40% of LPG-propane derived from the crude oil refining process.

This post provides a complete guide to the safe storage and handling of LPG stored under pressure in cylinders or tanks, as outlined in the Australian Standards AS/NZS 1596:2014 The storage and handling of LP Gas and AS 4332-2004 The storage and handling of gases in cylinders.

What is LPG Used For?

LPG is used all around the world for thousands of applications, in commercial businesses, industry, transportation, farming and agriculture, power and energy generation, cooking, heating and for recreation activities such as camping.

Liquified Petroleum Gas, or LPG, is used in thousands of applications, including portable outdoor heating

More than 300 million tonnes of LPG are consumed each year by more than a billion people across all six continents, including the remote bases in Antarctica.

How is LPG Used in Australia?

In Australia, we primarily use propane LPG, which has a lower boiling point than butane (-42C vs -0.4C for butane), making it more suitable in colder conditions. Although we do use butane for fire-lighters and candle lighters due to its superior performance as a propellant (thanks to its lower vapour pressure vs propane).

Australian homes use LPG for gas heating, gas hot water heaters, and cooking gas cylinders, typically when natural gas - or mains gas - is not available, as is the case in many rural and regional areas far from a mains gas network.

In the workplace, LPG is used in commercial and agricultural heat applications, including petrochemical feedstock, aerosol propellants, air conditioning refrigerant and fuel for generators.

LPG is also used as a fuel for vehicles - called Autogas - mainly because it is cheaper than either petrol or diesel and produces less CO2 and particulate emissions.

What are the Risks and Hazards Associated with LPG?

In Australia, LPG is stored as a liquid under pressure inside purpose-built cylinders or tanks of varying sizes.

The requirements for safely handling the cylinders containing these Class 2 substances (as classified in the ADG Code) are outlined in AS 4332-2004 The storage and handling of gases in cylinders.

The Standard also outlines the various sizes and capacities of these cylinders and tanks, and the codes used to differentiate them from each other.

LPG cylinder sizes include:

• Size N and Size P - used with home BBQs and camping stoves
• Size Q/T and Size R - used to power forklift trucks
• Size S - commonly used for heating domestic homes, small businesses, and premises operating commercial gas appliances
• Size 90kg tanks - permanently installed and filled onsite at residential homes or businesses operating commercial gas appliances

LPG Cylinder Capacities and Dimensions

NOTE: Height includes valve protection ring

What are the Risks Associated with LPG?

Despite the vast range of uses and applications associated with liquified petroleum gas, it is a Class 2.1 Flammable Gas kept liquiified under pressure, so there is an array of risks to be aware of when using, storing and handling LPG cylinders in the workplace or at home.

The major risks of LPG include the following:

• LPG is extremely flammable - LPG cylinders must never be stored in an area where there are open flames, lit cigarettes, pilot lights, spark producing switches or tools, heaters, naked lights, and even mobile phones. Even the static electricity from a thermostat in a vending machine has been sufficient to ignite LP gas leaking from an LPG cylinder and cause a dangerous explosion at an American construction site.
• LPG is denser than air - Because LPG is denser, and therefore heavier, than air (and natural gas), any leaking gas tends to accumulate in low lying areas and confined spaces, dissipating slower than natural gas, and presenting an explosion (and asphyxiation) hazard. It is essential that LPG storage areas are well ventilated and located outdoors.
• LPG is an asphyxiant - Because LPG is colourless and odourless, detecting LP gas leaks quickly can be very difficult. Leaking gas can rapidly fill an entire room and reduce the breathable air, creating an extremely dangerous asphyxiation hazard. Adequate ventilation of LPG storage and handling areas is crucial, and in some workplaces, alarm systems should be installed and air quality testing conducted at regular intervals to detect possible leakages.
• LPG is incompatible with oxidants - LPG has the potential to spontaneously combust when it comes into contact with oxygen, halogens, and metal halides. It is essential that all LPG cylinders (either full or empty) are properly separated and segregated (minimum of 3 metres) from other flammables and oxidants.
• LPG is liquified and extremely cold - The boiling temperature of LPG is -42C, so if the evaporating liquid or free-flowing gas comes into contact with human skin, it can inflict ice burns, similar to frostbite, causing permanent skin and tissue damage. Adequate PPE is essential when handling LPG cylinders, including safety glasses, leather/insulated gloves and work/safety boots

What Hazards are Associated with LPG Cylinders?

LPG doesn’t only present health and physiochemical hazards. The LPG cylinders themselves pose several other hazards that should be recognised and controlled, including the following:

• Manual handling injury - LPG cylinders can be heavy and difficult to manoeuvre without adequate aids such as trolleys and lifting devices. Handling large or even small cylinders incorrectly can lead to muscular and strain injuries, or even broken bones if a cylinder topples or falls onto an unprotected part of the body. Again, suitable PPE is required for moving or transferring cylinders from one place to another.
• Damaged cylinders - The valves on LPG cylinders are particularly susceptible to damage if the cylinder is dropped or falls over, leading to the very real possibility of an uncontrolled leak or dangerous explosion. Regular inspections, along with appropriate repairs carried out by qualified technicians, are necessary to ensure the ongoing safety of anyone working or moving in proximity to LPG cylinders. The condition of cylinders must be clearly marked, whether intact, empty or damaged in any way.
• LPG cylinder connections - Every connection point between an LPG cylinder and the appliance, tool, process or vehicle it’s fuelling presents a potential hazard. Substandard materials or even poorly aligned fittings can cause catastrophic situations involving leaking gas or explosions. Connecting hoses and fittings must be made from materials compatible with flammable gases and should be secured by qualified technicians. Regular visual inspections should be scheduled and conducted, and appliances disconnected when not in use or when cylinders are in storage.

What are LPG Bottle and Cylinder Regulations?

Requirements for minor storage quantities of compressed gas cylinders - as outlined in AS 4332-2004, Section 2 Minor Storage - should be applied to your cylinder stores if you handle or store less than 500 litres of LPG (combined with other Class 2.1 Flammable Gases).

Where to Position LPG Cylinders

Storing LPG cylinders indoors is not recommended - largely due to the odourless gas’s propensity to accumulate in low-lying areas undetected and rapidly fill an entire room, presenting a high risk of asphyxiation to anyone present, or an explosion caused by an ignition source such as static electricity.

An outdoor location is ideal, preferably inside a sturdy gas bottle cage made from heavy-duty materials with cylinder restraints or safety straps.

Watch the following short video to see an example of an AS 4332-compliant LPG gas bottle storage cage.

The LPG cylinder storage area should not be too close to pedestrian or vehicular traffic, and ideally should be fenced and secured from unauthorised access. If it isn’t practical to position the cylinder store away from the paths of vehicles, bollards or crash barriers must be installed to minimise the risk of damage to the cylinders from vehicles.

When deciding on the location of LPG cylinders:

• Ensure the cylinder store is at ground level;
• Ensure the stores are positioned as far away as practical from site operations and machinery that generate sources of heat, such as steam pipes, boilers, radiators, engines, mufflers/exhaust, etc.;
• Ensure combustible materials such as garbage and vegetation do not come within three (3) metres of LPG cylinder stores;
• Ensure the site where the store is located is levelled and/or sloped to allow for suitable drainage without compromising cylinder stability; and
• Ensure entryways and exit points to LPG cylinder stores are kept clear at all times.

How to Segregate and Separate LPG Cylinders

For the purposes of segregation, the Australian Dangerous Goods (ADG) Code differentiates Class 2: Gases into three (3) separate divisions.

• Division 2.1: Flammable gases, such as LPG, hydrogen, or acetylene
• Division 2.2 (5.1): Non-flammable, oxidising gases, such as compressed air, or oxygen
• Division 2.3: Toxic gases, such as methyl bromide, anhydrous ammonia, or chlorine

Flammable gases such as LPG must be segregated from oxidising gases (such as oxygen) and toxic gases.

Segregation can be achieved in two ways:

1. Physically locate cylinders containing incompatible gases at least three (3) metres apart.
2. Install a barrier between the incompatible gases - such as a screen wall constructed from materials that are non-combustible and impervious to gas vapours, and made at least one (1) metre taller than the top of the highest cylinder in the store.

NOTE: Empty LPG cylinders are not actually completely empty and still contain some gas, so they must be stored and handled as carefully as full cylinders. Empty LPG cylinders must be labeled ‘EMPTY’, separated from full cylinders, and segregated according to their hazard classification as flammable gases.

LPG cylinders should be individually restrained in purpose-built racks or cages

Additional Requirements for Storing LPG Cylinders

Both Standards - AS/NZS 1596:2014 and AS 4332-2004 - outline additional compliance requirements related to the storage and handling of LPG cylinders, including:

• Ventilation (AS 4332-2004, Section 4.3) - LPG cylinder stores must be adequately ventilated to reduce risk of asphyxiation, either through the provision of fresh air or the installation of a mechanical ventilation system to achieve safe oxygen levels at all times
• Buffer zones - Outdoor LPG cylinder stores must be situated at least one (1) metre from any windows, doors, air vents and ducting.
• Ignition sources - Any potential source of ignition, including anything that could generate static electricity (such as a mobile phone), must not be located in the store.
• Cylinder restraints - LPG cylinders must be stored upright, with their valves closed, attachments and appliances removed, and safety caps in place - preferably in a secure gas bottle cage or gas cylinder rack compliant with Australian standards, with each cylinder individually restrained using safety straps or chains.
• Safety Data Sheets - LPG cylinder stores require appropriate Safety Data Sheets (SDSs), along with an updated Register of hazardous Chemicals, and potentially a Manifest of Hazardous Chemicals (required for large quantities of LPG stored on site).
• Signage - As dangerous goods, LPG cylinders and their stores require adequate signage and placarding, including a Class 2.1 Flammable Gas Dangerous Goods Class Label, and the GHS04 Gases under pressure GHS Pictogram.

LPG cylinder store signage and placarding requirements

Dangerous Goods Class Label

GHS Pictogram

Hazard Sign

LPG Safe Storage

If you’re looking for further information about LP gas cylinder storage in the workplace, dangerous goods specialists STOREMASTA have developed a free eBook, Gas Cylinder Storage: Compliance and Safety Requirements, that you can download right now, featuring real world examples of workplace incidents and accidents involving gas cylinders.