Safe Boobytraps: Tear Gas and Unknown Contents

Safe Protectors

When people acquire locked safes, the most natural reaction is wanting to know what's inside.

Let me be the first to tell you:
Old or new, most locked-up safes acquired without combinations will prove to be empty.

Obviously there are exceptions, but for the most part you shouldn't expect to find someone's valuable forgotten/abandoned stash of money, jewelry, or whatever.

True enough, the only way to know for sure is to open it and do a thorough inspection. It's also a fact that a small percentage of such safes do have contents.

Until you know, the answer to the "what's inside?" question is "anything that fits." Contents really can be anything, ranging from worthless to worthwhile.

No matter what opening process you choose, though, be careful the first time the door swings. Just as a locked safe can hold valuables, it can also hold dangerous things. What follows here might have you thinking twice about tearing it open yourself, "because the safe company wants too much money."

Sometimes law enforcement people call for safe openings while executing search warrants, when the owner can't or won't comply with requests to open it. Cops can get impatient. Sometimes they'll have a go at forcing a safe open themselves instead of waiting for a technician to show up. When this happens their methods are typically pretty rough.

One good reason for using caution when a safe with unknown contents gets opened is that when I tell you a safe can contain anything that fits, it's no exaggeration.

Some older safes were booby-trapped to guard against being forced open by burglars.


Starting around the 1920s, there was a thriving market for add-on anti-burglary devices for safes and vaults. People in the safe and vault business refer to these devices generically as "tear gas devices" or "safe protectors."

A safe fitted with a commercial anti-burglary tear gas device could render a decent-sized building uninhabitable for several days or more. Such devices were rigged to disperse noxious (and undoubtedly toxic) gases when activated. A whiff or two of such stuff would send an average person running for the nearest exit.

These are front and rear views of two popular safe tear gas devices.
Commercial tear gas devices usually consisted of one or more glass tubes mounted inside a metal housing. The entire contraptions were designed to be affixed to safe doors, near the lock.

Sealed inside the glass tubes was a liquid that stayed liquid as long as the tubes remained intact.
If a safe was rigged with an after-market tear gas device, however, any physical disruption of the type favored by safe burglars (spindle punching or torching) broke the fragile tube that held the tear gas. The liquid reacts quickly to contact with air, forming a literal cloud of noxious, irritating vapor that burns eyes, noses, and throats while causing uncontrollable coughing and retching.

Burglars who attacked safes knew that if they could defeat the safe's lock, the safe would open. However, most burglars only knew enough to defeat safe locks by brute force attack. Not many burglars could defeat safe locks without using destructive force. Tear gas device makers relied on this.

Typical Safe Burglary Attack

A typical safe burglary attack went as follows:
Knock the safe dial off with a hand sledge, exposing the dial spindle.

Use the punch to drive the dial spindle (it connects the dial to the lock) inward with a punching tool.

The object was to knock the main lock components as possible off the inside of the safe door and thus overcome the locking function.

Often the burglar(s) would have to "fish" for one or more of the lock components with bent wires and such if the punching attempt failed.

After that, all the burglar had to do was turn the door handle, swing it open, and start extracting loot.

The tear gas devices worked well. Safe burglars who swung doors of tear gas-protected safes expecting a big payday instead found themselves doubled over almost immediately, enveloped in a cloud of tear gas, coughing and retching uncontrollably, with eyes, noses, and throats tearing and burning. Those who had such Pavlovian experiences usually abandoned any thoughts of gathering up loot and instead counted themselves lucky to make their coughing, retching getaways.

Today it's illegal in most states to rig an injurious booby-trap of any kind. However, when tear gas devices were being marketed, nobody worried much about treating safe burglars like endangered species. Today it's a criminal offanyone who knowingly rigs such a device anywhere on his or her premises is liable for criminal charges. As a result, most tear gas devices rigged on safes and vaults have been removed and disposed of by now. The operative word there is most.

Because so many old safes survive and continue working decade after decade, not every old tear gas attachment has been removed. The chemical agents inside those surviving devices are still potent, still noxious, and still capable of making a building temporarily uninhabitable. 

I've found and removed a number of tear gas booby-traps from the doors of old safes. It's easy to understand why some are still out there even now. Safes from "the old days" tend to keep on working with minimal service. "Minimal" in this case often means decades without service.

Quite often I'm the first person in a long time to do any service on the safe I'm working on. If a safe has a tear gas device, it's generally not visible or evident to the owner. Such devices are typically concealed by a screwed-on cover, some are under the service panels attached to the back of an average safe's door.

While it's becoming increasingly uncommon to find tear gas devices nowadays, there are still a few out there. If I see one still in place I'll point it out to the owner, explain what it is, and offer to remove it. Once they understand what it is, the owners are usually all too happy to see the device removed .

Luckily for me, the methods safe technicians use to open safes don't usually include the kind of activities that trigger booby-traps like tear gas devices.

However, when safe owners try to force their own safes open they tend to use grossly destructive methods. If by chance there is a tear gas device present, the unschooled safe opener has a much better chance of making a move that will trigger it. As one World War II Army commander put it in a discussion about the tendency of souvenir-seeking soldiers to fall victim to booby-trapped enemy bodies, "booby traps for booby troops."
The Night Hawk "Gas Gun" was another popular brand of
tear gas device for safes.

Tear Gas Mythology
For a long time, what amounted to a locksmith campfire story held currency in the safe industry. It was to the effect that tear gas in commercially sold and installed safe protectors would deteriorate over time and become nitroglycerine.

More than one technician who found an old tear gas protector still in place on a safe actually believed this drivel, which had no basis in fact. They went so far as to summon local authorities (police bomb disposal squads, fire departments, etc.) and relate this mythology. Lacking authoritative information to the contrary, in the interest of public safety and prudence the agency would proceed as if defusing a real bomb.

The truth? That's straw-into-gold alchemy, with zero basis in science. Every once in a while the myth got revived in lock and safe trade journals or on internet forums, wherein some member would repeat and perpetuate the story. Then others would solemnly chime in with "reminds me of the time . . ." stories of similar experiences.

When questioned as to the provenance or the chemical reality of their tear gas-into-nitro stories, the storytellers indignantly defend their tales. None of them ever have any verifiable citations to give regarding times, dates, agencies, chemical analyses by accredited agencies, nothing. Why? Because it's not true -- the compounds used in commercial safe protectors do not decompose or otherwise change into explosives.

To be sure, the compound used in most tear gas protectors is definitely noxious and toxic to humans, but to repeat, it doesn't decompose into nitroglycerine or anything else volatile or explosive. I did some homework on this. The compound used most often in safe protectors is called chloropicrin. Chloropicrin is still used in agriculture as a fumigant and wholesale rodenticide. It's as much of an irritant now as it ever was, and is no less noxious. However, it's not and never will be nitroglycerine or its equivalent.

Other Safe Booby-Traps
There's yet another class of safe booby-trap: It's the one that's home-made, conceived, devised, and rigged by safe owners. These are potentially more dangerous. Home-made safe booby-traps can be anything, made from whatever explosives the safe owner can get access to.

Drug dealers and illicit lab operators are notorious for booby-trapping their safes. This is something you might expect from drug dealers, but any safe owner with a little mechanical know-how and who is paranoid enough can rig safe door with a booby-trap. Some safe owners have rigged their safes with explosives that are detonated by something as simple as swinging a door open, but no two are alike. Luckily, neither are such devices common, but it pays to use care the first time one opens a safe that was acquired with unknown contents.

In view of this, and especially in light of the fact that even rookie patrol cops are trained to religiously observe protocols for officer safety during roadside vehicle stops, it's nothing short of amazing how many cops executing warrants will immediately resort to brute force tools on safes they find with no thought whatsoever of potentially dangerous contents.

I've been lucky; only one safe I opened for law enforcement was booby-trapped. The police who hired me had detained a man for weapons violations. After they sent him to a hospital for mental evaluation they thought it might be prudent to search his home.

His safe was in the garage. On the way in from the driveway I noticed  a booby-trap rigged in the doorway. It was one of the few remaining legally-produced types, mounted at eye level on the door frame and designed to be triggered by a PIR (passive infra red) sensor. Walking past it when it was armed would trigger a blast of pepper spray in the face and eyes. Cute . . .

If you acquire an old safe and notice something inside you think might be an old tear gas protector, don't panic, be practical . . . It’s probably been there for years; chances are very good there’s no immediate risk of spontaneous discharge. So don’t hit the panic button. In fact, a loaded pistol loose on a shelf in a safe poses more potentially immediate danger than a tear gas device in a protective cast iron shell that is screwed to a safe door. Have a safe technician remove it.

Real non-commercially produced booby traps with real explosives can be inside any safe, not just old ones. Not common, but not unheard of.

“Other” Explosives: That’s right, don’t forget explosives of the other kind. Items like improperly stored black powder, fireworks, or other illegal ordnance. Again, if it fits inside,  it could be inside.

In fact, what follows is excerpted from a recent news article in a Swedish newspaper:

"The theft occurred in the Ã…kersberga region south of the capital on Sunday night reports the Mitt i a Stockholm newspaper. Staff discovered the safe had gone missing and alerted the authorities.

According to local police, the thieves risk blowing themselves up if they attempt to pry open the safe to discover the contents.

"They probably think it has money but in fact the safe has ten kilos of gunpowder. A man who works at the company said that is enough to move 40 tonnes of rock," said Mikael Pelagalli to Mitt i Stockholm.

He added that the safe will likely blow up if the thieves use a blowtorch to cut it open. Police are using the media in order to warn the burglars about the risks of their raided goods before it is too late."


Last, and perhaps most common: Loaded firearms are real possibilities, too. If found, firearms should be removed by somebody who has experience handling them.

Readers' comments are always welcome

Ken Dunckel

San Francisco Bay Area








Jessie Vera said…
Those safes are so vintage and cool looking! I love reading about interesting facts like this especially old things and history. I really enjoyed your post.

Jessie |

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