Repelling Robbers and Foiling Burglars and Thieves with Security Fog

Repelling Robbers and Foiling Burglars and Thieves with Security Fog

According to the FBI, every 1.5 minutes a robbery occurs somewhere in the United States and a burglary occurs once every 16.4 seconds. It is estimated that almost 9 MILLION property crime offenses occur each year in the United States. No one knows for sure, but in an effort to keep safe and to keep their property secure, it is estimated that American businesses and private individuals spend more than 100 BILLION each year on private security (alarms, security guards, fences, gates, locks, etc.). Not surprisingly, according to the United States Department of Labor, the private security industry is one of the fastest growing industries in the nation. The United States is not alone. In almost every country in the world there is a continual need to take security measures to thwart robbers and thieves and foil other assorted crooks.

One of the more interesting security measures businesses (and even some private individuals) are employing is Security Fog.

Imagine these scenarios: 

  • Two armed robbers enter a jewelry store intent on doing a “take-down” style robbery. As soon as they get inside the front door one thug points his sawed off shotgun at the manager and the other has a hammer in his hand intent on smashing the display cases and gathering up the jewels. Before the two robbers can yell at the clerk, “THIS IS A ROBBERY! Everyone get down on the floor!” a heavy plume of fog suddenly bellows out from the walls and ceiling, almost instantly flooding the entire store with a heavy layer of fog so thick that the robbers can no longer see more than a few inches in front of them. At the same time a super loud ear piercing siren goes off and blinding strobe lights make it even more confusing. The two thugs, now shocked – stunned – and totally confused, quickly flea in utter fear and confusion.
  • At 2:00 AM when all is quiet, a burglar is working the night shift. The burglar climbs onto the roof of a business and shimmies into the attic crawl space via a heating vent. He then drops down through the sheetrock ceiling and into an office containing the company safe and other valuables. As soon as his feet hit the ground, the room is consumed with a layer of fog so thick that it is impossible for the burglar to see the shoes on his feet. Somehow, the burglar stumbles to the front office area and manages to make it out the front door. The police arrive and find the dazed burglar a few blocks away still wondering what the heck happened.
  • A car thief breaks into a high value luxury car. As soon as his rear end hits the driver’s seat the car suddenly fills with a thick fog making it impossible for the thief to see his hand in front of his face let alone see well enough to hot-wire the ignition and drive away. Socked, dazed, and totally frustrated, the thief jumps out of the car and flees into the dark of night.

All of these crooks were stymied and foiled by one of the more unique security systems available – Security Fog.

What is Security Fog?

Security fog is sometimes called security smoke. While the concept of security smoke and security fog devices are similar, security smoke is not the same as security fog. Fog security devices operate on the principle of adiabatic fluid expansion caused by a high-temperature heated nozzle. When activated, a thermally generated water based fog is expelled through “nozzles” or emitters strategically placed inside the area to be protected.  In real simple parlance it is similar to theatrical fog.

These systems can be set to activate automatically when a robbery or burglary alarm is triggered or they can be activated manually with a panic alarm button. When triggered, it fills a room within seconds with a thick fog so dense that a person cannot see their hand in front of their face. This fog is designed to deter perpetrators from entering protected areas and to repel them if they should somehow gain entry to a protected area. It operates on the premise that one cannot steal what one cannot see. Some fog systems are coupled with blinding strobe lights and ear piercing sirens or horns designed to further disrupt the perpetrator. At least one manufacturer has even infused the fog with DNA molecules which attach to the intruders clothing allowing police to use DNA to place the intruder at the scene of the crime.

To really understand how security fog works, it helps to see it in action. Take a look at these dynamic videos from manufactures that demonstrate how it works:

 Does it Really Work?

All security systems always represent a balance between affordability and effectiveness. Many other factors like ease of installation and maintenance, costs, disruption of work process, and potential legal liability must also be factored into all security system decisions. While absolute protection is usually not practicable, effectiveness is the final test of a particular security system. If it does not work – everything else is meaningless.

Just how effective is security fog at foiling crooks? Security fog systems have been around for several decades and manufactures of security fog systems tout their effectiveness but I am not aware of any empirical research on this subject. But, security fog has been used for decades in the United Kingdom, Australia, South Africa, and many other countries including, to a lesser degree, the United States. And, there have been many real-life documented instances where security fog has foiled certain crimes like burglary and robbery.

Security Fog systems are more prevalent in the United Kingdom and in countries like Australia, South Africa, and Canada than they are in the United States. While I am aware of businesses here in the United States that use them, they are not considered “mainstream.”

Concerns over Security Fog

The lack of Security Fog systems in the United States is partially because of unfamiliarity with the product, but many security managers, security consultants, and business owners have concerns over Security Fog devices. Most of these concerns center on occupational health and safety concerns for building occupants and emergency responders and there are always the liability considerations.

  • Health and Legal Concerns.

Because fog emitted from these systems is predominately water based, the consensus of existing scientific literature suggests that the fog itself is non-toxic and does not cause any health problems under normal conditions. But you can be assured that if a customer, employee, or maybe even a crook, inhales any amount of this fog sooner or later someone will file a law suit claiming that the fog caused a serious medical condition or at least aggravated a pre-existing medical condition.

  • Risk to Firefighters and emergency responders.

The possibility that fog security devices could set off false fire or intrusion alarms causing firefighters and police to rush needlessly to the establishment is a concern. This is not a minor concern considering that the National Fire Protection Association reports that “The number of [firefighter] deaths that occurred while responding to or returning from calls has averaged about 24 per year over the past 10 years and 17 per year over the past five years.” For law enforcement, the concern is even greater. The leading cause of on-the-job deaths for police officers is not gunshots – it is traffic fatalities often occurring when responding to calls for service.

In an actual intrusion where a fog security system is deployed, there is a potential risk to responding firefighters and police officers if the fog has not repelled the intruder. The risk that an intruder could still be hidden in the fog when firefighters or police arrive can be mitigated by proper installation and positioning of the fog emitters, but this remains a concern.

  • Safety Hazard.

The possibility that the deployment of fog security devices could block egress by tenants or customers creating a safety hazard or a man trap situation is a real concern. Again, this risk can be mitigated by the proper installation and positioning of fog emitters, but when fog starts filling a room and lights and sirens start blasting, some people can panic and do some irrational things like running into the fog instead of moving away from it and exiting the premise.

There is also a concern that robbers who are suddenly faced with streams of fog, blinding strobe lights, or ear piercing sirens, might panic and just start shooting wildly. After all, many robbers are on drugs or are mentally unstable in the first place.


There are potential liabilities with Fog Security systems but there are also risks with any security system. Utilizing any security measure requires thoughtful consideration and the potential benefits and all security measures must be measured against the potential costs and risks. Because Fog Security systems are designed to prevent loss from a premise rather than deter entry they should only be used as part of a layered security approach. Only after an intruder has breached the premise should the intruder receive the fog treatment.

Aside from working as a Private Investigator in my home State of Oregon, I also provide security consulting to businesses and individuals throughout the Pacific Northwest. On occasions, especially when there is a need to protect a high value target, I have recommended to clients that they seriously consider installing a Fog Security system as part of an overall security plan. These systems are relatively inexpensive, allow for flexibility and scalability, and are easy to use and easy to install as they usually do not require a hardwired high-voltage supply. And, most importantly they work!






George W. Babnick, is a 34 year law enforcement veteran with an extensive background in physical security, criminal and administrative investigations, training, school policing, supervision and management, and criminal forensics. He retired as a Captain in the Portland Oregon Police Bureau where he managed the Training, School Police, and Forensic Evidence Divisions. He holds criminal justice degrees from Portland Community College and Portland State University and a law degree from Northwestern California University School of Law, Sacramento California. Mr. Babnick is a longtime member of the Western Society of Criminology and is the author of articles on security and law enforcement, investigations, supervision and management, and risk management related to these subjects. As a physical security expert, George Babnick provides private physical security consultations across the United States and consults with clients outside the United States. He specializes in assessing security problems for small and medium businesses as well as select individuals. He offers independent, honest advice and expertise, with the goal of providing all clients with practical and cost-effective security solutions to enhance security and effectively manage business and personal security risks. Mr. Babnick is also a licensed Private Investigator and conducts investigations for attorneys, businesses, and individuals throughout the State of Oregon. To learn more about security consultation and investigative services offered, please visit Disclaimer: Nothing in any article on this blog should be construed as legal advice. Persons seeking legal advice should seek the counsel of an attorney licensed in their state.