Do Fog Machines Set Off Smoke Alarms?

The answer to the question “Will a fog machine set off a fire alarm?” is yes. Fog machines may trigger fire alarms due to the particles they emit being detectable by alarm systems. Smoke detectors can be triggered by fog, smoke, and haze.

If you want to avoid setting off the fire alarm with your fog machine, then opting for a low-lying fog machine can be your best choice, or switching out the smoke detector to one which uses heat sensors instead. Otherwise, you could end up in quite an embarrassing situation!

Do Fog Machines Set Off Smoke Alarms

Fog Machines and the Various Sort of Fire Alarms

Fog machines are often used in the entertainment industry to give a special effect, but what many people aren’t aware of is the potential impact that fog might have on fire alarms.

Depending on which type of machine you’re using, certain alarms can be triggered when a substance is released into the air.

1. Low-Fog Machines

Low fog machines create a low-lying fog and are popular for Halloween decorations and wedding dances. They release very thick smoke that stays close to the ground, cooled by either dry ice or liquid CO2.

2. Smoke Machine or Fogger

Regular fog/smoke machines are more commonly used at parties and clubs; they produce thicker smoke that fills up an entire space.

3. Haze Machine

Hazers offer a more subtle effect – rather than creating thick smoke, they instead produce haze around the room, making it visible only when it reflects off of light sources like lasers.

All these machines produce either a cool or temperate output but may still set off a fire alarm due to the thickness of their effect and their ability to spread.

See also  Fog Machine Chillers — An Ultimate Guide

4 Types of Sensors are Involved in Fire Alarms

When it comes to fire alarms, four different types of sensors are involved – ionization smoke detectors, photoelectric detectors, heat detectors, and carbon monoxide (CO) detectors.

1. Ionization Type Smoke Detectors

Ionization smoke detectors detect particles from the smoke that enter the apparatus and will be triggered if enough particulates get in.

2. Photoelectric Smoke Alarms

Similarly, photoelectric detectors rely on a beam of light that’s stopped if it is interrupted by the particulate matter; when this happens, the receiver no longer receives the light which triggers an alarm.

3. Heat Detectors

Heat detectors set off when the temperature rises too much, notifying you of potentially dangerous conditions.

4. CO Detectors

CO detectors additionally detect carbon monoxide levels that may also be produced by fires.

Combined, these four types of sensors create an effective system for detecting fires and alerting those nearby. Now you know why there are so many kinds of fire alarms!

The following table indicates which smoke machines will trigger alarms.

 Low fog machinesFog and smoke machinesHaze machines
Ionization smoke detectorsNot likelyVery likelyLikely
Photoelectric smoke detectorsNot likelyVery likelyLikely
Heat detectorsNoNoNo
CO detectorsNoNoNo

How to Make Sure the Fog Machine Will Not Set off the Alarm

To make sure that your fog machine won’t set off the fire alarm, it is important to do some prior testing. Identify the location of the smoke detectors from the event organizer and position the fog machine at a suitable distance.

See also  Does Dry Fogging Work for Mold Removal

It’s also a good idea to know where the switch for the alarm is located in case you do need to switch it off. It is recommended to have a fire marshal present during equipment testing, in order to prevent false emergency signals from being acted upon by the fire department.

To minimize the possibility of triggering an alarm, consider constructing a cover around the nozzle as well. Cooled fog will help maintain a low altitude and reduce the chances of interference with sensors.

Finally, check with the owner of the venue ahead of time about their fire detection system and make sure never to touch any alarms without their consent or approval.


Can Fog Machines Be Used Indoors?

It is possible to use a fog machine inside the house; however, there is potential for carpets and other surfaces to become damaged due to the fog settling in.

Is It Safe to Use a Fog Machine Inside?

Using a fog machine inside a house can add an extra level of spooky fun to your Halloween party. However, it is important to note that indoor fog fluid may leave behind a slippery residue, and may irritate the breathing of those with asthma or sensitivities.

Will a Haze Machine Trigger a Fire Alarm?

Haze machines create a thinner fog, reducing the chance of triggering fire alarms. The type of sensors and the size of particles matters, as oil-heavy hazers are safer than water-heavy ones. To be safe, I recommend doing smaller tests before a gig.

Can I Turn off the Fire Alarm Then?

It is not advised to switch off a fire alarm, but it can be requested by a fire marshal. With their consent, they may allow the area to be monitored closely. Typically, this needs to be conducted by the fire marshal themselves.

How Long Does Fog Machine Smoke Last?

Fog juice will last 6 hours with a 400-watt machine, 4 hours with a low lying machine, and 2 hours with a 1,000-watt machine.

Is a Fog Machine the Same as a Smoke Machine?

Smoke machines, commonly known as fog machines, generate thick white smoke by dispersing a special fluid and can frequently be operated via remote control to modulate the intensity or duration of the produced fog.

Can a Fog Machine Set off Sprinklers?

A fog machine by itself will not trigger sprinklers. Sprinklers can be manually or heat activated. If the fire alarm includes smoke detectors, however, it can activate the sprinklers along with other systems.


In conclusion, fog machines can indeed set off smoke alarms if they are not used properly. For this reason, it’s important to never leave a fog machine running unattended and also to carefully research all safety precautions related to the use of fog machines before using one in your home or business.

With some simple preparation and understanding, you can safely enjoy your fog machine without worrying about setting off any smoke alarms.