News & Media

Learning from experience – anti-theft fog machine

By: CFA News

Category: Operational Information

  9.43 AM 11 January, 2018

Location: General

Views: 695

Each issue of Brigade magazine contains a ‘Learning from experience’ section which includes case studies of major incidents researched by Fire & Emergency Management.

A case study is an explanatory story based on a real-life incident that looks at what happened and why it happened. The aim is for people to learn from the case study so they improve their decision making in time-critical situations.

Each case study gives an overview of the incident containing all the important facts and a list of lessons identified. These lessons will help CFA members in a similar situation to make good decisions. 


CFA crews have identified a new type of security alarm found in residential houses known as portable anti-theft fog machines or smoke security devices. They are hired to generate smoke/fog to deter potential burglars.

The units expel dense fog in the protected area in a matter of seconds, forcing the intruder to exit the premises empty‑handed.

There are many such devices on the market and they are being used more frequently across the metropolitan and outer metropolitan areas. The use of these devices has led to safety concerns for emergency services responders. Two recent incidents that highlight these concerns are described below.

Incident overview

On 20 August 2017 at 3.46pm, Officer and Pakenham brigades responded to a reported house fire which was under construction in Officer. The Pakenham pumper was first on scene and the crew observed smoke issuing from the house through the roof.

The incident controller requested an extra brigade to respond. When the Officer pumper arrived, it was tasked to provide two more breathing apparatus (BA) operators and help the Pakenham crew enter the house.

Within a couple of minutes, the Pakenham BA crew discovered there wasn’t a fire and that the smoke was coming from a security device placed inside the house. The smoke made its way through the roof because of holes in the ceiling meant for heating/cooling ducts.

The fog machine was unplugged and taken outside by the crew.

A thorough search of the house was conducted in case there was anyone inside. Victoria Police was requested to attend because of the suspicious circumstances. Brigade members spoke with a representative from the building company, who could operate the smoke machine remotely. The machine was reset after the brigades left.

Although it turned out to be a false alarm, the brigades didn’t know this when they arrived.

The second incident took place in similar circumstances two weeks later on 8 September, next door to the house of the first incident.

Lessons identified

  • When it has been identified that one of these devices is in use and is the cause of the smoke, it’s important that Victoria Police is notified immediately.
  • Crews should be aware there may be intruders in the area and the safety of firefighters is paramount.
  • There should be signs on the outside of the building alerting people that an anti-theft fog machine is being used. During size-up keep an eye out for them.
  • If available, use a thermal imaging camera to check for fire.
  • The smoke produced by these devices is very dense and visibility is poor, so follow normal search procedures and be especially careful when using stairs.
  • Bear in mind that these devices are common in new homes at lock-up stage prior to sale, and in display homes.

How anti-theft fog machines work

Smoke security devices are designed to fill the protected area with a dense cloud of smoke to significantly reduce visibility – you can’t steal what you can’t see. A device can fill a 10 metre by 10 metre room with an impenetrable wall of fog within 10 to 20 seconds.

The triggers for the device to activate are a break-in, when a door is opened, or when movement is detected by sensors in the building. Most products are harmless, using a glycol vapour to produce the ‘smoke’. A similar substance is used in theatres and discos. They leave no residue and are safe for humans, animals, food, clothing, furnishings, computers and electrical equipment.

Standard practice by companies installing a smoke security alarm is to provide warning signs on entry/exit doors to alert people.

Safety actions

  • If CFA crews are inside a building and a smoke security device activates, they must exit the building immediately via the entry route and wait for the security company to arrive.
  • CFA crews attending Triple Zero (000) calls for smoke issuing from a commercial/industrial or residential property should consider the possibility that a smoke device has been activated (before entering the building to investigate or before forcing entry).
  • If a crew is responded by Victoria Police to investigate smoke issuing from a building and a smoke device is identified as the cause, CFA members mustn’t enter the building.

CFA attendance at smoke security alarms

  • When a smoke security device has been identified, CFA crews must request Victoria Police to attend immediately.
  • If CFA crews are on scene before the security company or police arrive, and there are signs of a break-in, CFA crews mustn’t enter the building.
  • CFA crews mustn’t undertake salvage operations to attempt to extract smoke from the premises.

For more information read Safety Alert No 24.

Health concerns

Skin contact and inhalation of the smoke/fog shouldn’t affect a healthy person. However, it may cause mild eye and skin irritation. Wash the skin with water and soap and flush eyes with water. People with pre-existing respiratory conditions may be prone to respiratory irritation when exposed to this smoke. If irritation persists or recurs, seek medical attention.

Bear in mind that the biggest risk is the possibility that an armed intruder could still be inside the property when the crews arrive. This could pose a threat to firefighters working to ventilate the structure or determine the cause of a false alarm. It’s even difficult at times for the police to ensure that the building is clear due to the limited visibility.


As more anti-theft smoke devices are sold and hired to deter theft, CFA members may also see an increase in call-outs for smoke comingthrough roof tiles or from houses. The smoke from the house definitely looks like the real deal and, as a firefighter, you will never know until on scene if it’s a real job or not. A better understanding of these machines will mean better firefighting.

Last Updated: 11 January 2018