Petroleum & Gas Inspectorate | Alert | No.120 V 1 | 18 June 2025

Structure fire from venting gas cylinders

Summary

• A business in Townsville sustained significant damage when a fire caused gas to be released from the LPG cylinders.
• A build-up of combustible material (dry vegetation) around the cylinder area, ignited by unknown means, resulted in the intense heat to the cylinders and components causing failure and the release of gas.
• RSHQ’s investigation into the incident has been finalised and found that activities or assets of the fuel gas delivery network did not contribute to the cause of the fire.

Issue Explained

A fire around the area of the 3 x 90kg LPG cylinders caused damage to the regulator and pipework. This caused the gas to be released through the manifold at cylinder pressure which drastically intensified the fire. Once the regulator melted the manifold connection, due to its orientation, it had a direct source of heat onto one of the LPG cylinders. This caused the cylinder to vent from the safety relief valve, which also ignited from the fire, and caused significant damage to the building opposite the cylinders (about 3m away).

A resident from the units in the neighbouring property raised the alarm and attempted to extinguish the fire but was unsuccessful. The fire also caused some minor damage to the neighbouring property.

An investigation of the incident by the Queensland Fire Department (QFD), Queensland Police Service and Resources Safety and Health Queensland identified the probable cause was a large deposit of dried combustible vegetation, mainly palm fronds, which had caught fire. It is unknown as to what ignited the vegetation, but it is believed it may have been a discarded cigarette butt. The vegetation was located on the neighbouring property, directly behind the LPG cylinders, on the opposite side of a timber slat boundary fence.

The fire had a potential to cause a BLEVE (Boiling Liquid Expanding Vapour Explosion) situation which could have had devastating effects to both people and property in the area. The quick response by QFD prevented this from occurring.

Learnings

Although the LPG cylinders did not cause the incident, it is a timely reminder to fuel gas delivery networks of the effects that a build-up of combustible materials near LPG cylinders can have. Fuel gas delivery networks should:

• ensure that LPG cylinders are protected from or located away from areas where combustible materials could accumulate, even that of materials stored on neighbouring properties.
• check for a build-up of combustible materials during activities e.g. in-situ cylinder filling, exchanging cylinders and when conducting inspections, to ensure the areas are kept clear.

• ensure that cylinder safety relief valves (SRVs) are directed away from building and other structures, as well as not being directed towards other LPG cylinders.

References and further information

• AS/NZS 1596:2014 The storage and handling of LP Gas.
  • Clauses 4.4.11(g) and 11.5.12