Hair-Trigger Explosive

DANGER! DROP IT AND DIE!

Sarah Jane: Aha! This looks like it! [throws a box to the Doctor, who freezes in place] What's wrong; not enough?
The Doctor: Sweaty-gelignite-is highly-unstable. One good sneeze could set it off. [carefully puts the box on the floor]
Sarah Jane: Sorry.
The Doctor: No sign of any detonators or fuses?
Sarah Jane: No, no, nothing else. Perhaps he sneezed?

— Doctor Who, "Pyramids of Mars"

There are powerful explosives and can blow up almost everything. But Hollywood gives it a nasty drawback: anything can make it explode. Anything. You have to be super-careful or it will blow up. Or maybe it blows without any apparent reason.

Some Real Life explosives really have a hair trigger, some...don't. A good part of RL explosives development goes to making sure that the stuff blows up when it's supposed to and not before - a bomb that destroys the bomb handler before it can be placed on the thing intended to be blown up is worse than useless - but that doesn't mean that older, less reliable explosives can't still be made or obtained. Note that most explosives in fiction are not depicted this way. Usually in fiction, a plunger or a similar device (e.g. with a blasting cap, fuse, Plunger Detonator, etc.) is used to safely blow up explosives. But also in fiction, they get the volatility of explosives wrong, especially TNT and dynamite.

In video games in general, Exploding Barrels can be usually detonated even by punching or striking them with any melee weapon. Grenades and flamethrowers also have a tendency to explode when the person carrying them dies, especially in strategy games.

Subtrope of Stuff Blowing Up and The Last Straw. Supertrope of Nitro Express. Also see Explosive Stupidity when someone doesn't know this. This applied to a car intentionally is Molotov Truck, and unintentionally is Every Car Is a Pinto. Compare/contrast Made of Explodium, in which something that should not be explosive explodes anyway. If the compound explodes with ridiculous intensity rather than ease, see Ridiculously Potent Explosive. If a nuclear weapon is treated like this, it's Artistic License – Nuclear Physics. In comedic works, the volatility of stuff is directly proportional to how funny the consequences of the resulting explosion will be.

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Examples:

Comic Books

• Parodied in Mortadelo y Filemón, were this happens at least two times and both casually when Mortadelo y Filemón return to their base with the explosive and are with the Súper. In one case the explosion sends the three to Saturn.

Fan Works

• Discussed and averted in Finishing the Fight: When Keyes and Johnson take out the weapons of mass destruction, Johnson comments:

  Johnson: You will not trigger these things by banging, dropping, or otherwise manhandling them. [closes the second case] Nevertheless, and I want everyone to hear me very carefully here, you treat this shit as if it were armed, and the slightest jostle could set it off. You treat it as if the very second you stop respecting it for what it is, that it will kill you.

• The Next Frontier: Mentioned in passing after a... lively incident involving some improperly stored Chlorine Trifluoride, which is a real life example of this trope and Made of Explodium: The Kerbin Space Agency very briefly experimented with using it as rocket fuel^note or oxidiser, technically before giving it up as a bad job, because while it would have been incredibly powerful it was too unstable to be safely used.
• Robb Returns: According to Tyrion Lannister's research, unless wildfire is badly mixed and is stored in the wrong conditions, it will not degrade, but instead mature and grow more and more unstable, especially if kept somewhere dark. It's thus a giant Oh, Crap! moment when it's revealed that Aerys Targaryen buried numerous caches of the stuff under King's Landing, which had been there since Robert's Rebellion and which Jaime Lannister had never told anyone about, meaning that an entire city is sitting on a giant firebomb just begging to go off.

Film — Live-Action

• A Curious Conjunction of Coincidences: Zigzagged with an airplane bomb. Averted at first, when it fails to go off when accidently dropped over Amsterdam during World War II, and spends several decades in the ground undetected. But ultimately played straight when it is finally triggered by an empty cola can that falls on top of it.
• Played straight and later subverted in Die Hard with a Vengeance. The liquid/gelled binary explosive used in the movie, PLX, actually exists but neither looks like it does in the movie nor does it explode on impact (instead requiring at least a blasting cap). It's also certainly not energetic enough that the amount collected on the tip of a paper clip would be enough to flip a chair. Seen later on, the actual bombs made with it feature more realistic amounts of priming explosives.
• In Grand Slam, Gregg opens the safe with specific nitroglycerine charges. Later, when being chased by the police, Weiss takes Gregg's flask of nitroglycerine and hurls at the police cars behind him, where it explodes in a fireball as soon as it hits the road.
• In The Legend of Zorro the villains' plan involves a train full of nitroglycerine. To demonstrate, one tosses a small drop onto the floor causing a huge explosion.
• The first Rush Hour movie has Carter shoot at a car trunk filled with C-4 and trigger a fairly small, fiery explosion, which the driver of the car even survives. C-4 is known for being incredibly stable and cannot be detonated with gunfire. It's also far more powerful and far less pyrotechnic than is depicted in the film, but that's neither here nor there.
• The Wages of Fear also codified Nitro Express. In this film, four drivers needed to transport nitroglycerine for a long distance in a bumpy road.
  • Ditto for its William Friedkin remake, Sorcerer. It's even worse in Sorcerer than it was in The Wages of Fear: due to abysmally bad storage conditions, the TNT they're transporting has leaked all the nitro, meaning that, unlike the (relatively) safer jerrycans, they're carrying parchment bags of nitroglycerine.
• In The War Wagon, Billy uses nitro to blow the bridge, leading to several nail-biting moments as he clings to the underside of the bridge and attaches the bottles.
• Zigzagged in Wild Wild West: at the beginning, Jim West crashes a weapons deal only to find out that the weapon in question is nitroglycerine, transported in glass bottles that are stored in wooden crates with no padding. He even says "This is not how you store nitro!" But it doesn't explode at any point.

Literature

• Firebombs in An Outcast in Another World are to be handled with care. They’re powerful explosive that detonate when sufficient pressure is applied to them – which can be as light as someone throwing them across a room, or stabbing them with a knife.
• Briefly discussed in the children's novel Ghost Town Adventure. Abe Winters, mayor of the eponymous ghost town, tells the children about a time one of his burros had fallen down a cliff while packing a load of dynamite. Chuck (the youngest) asks if the burro blew up and Abe says no, all that happened was the burro got a bruise on its tailbone.
• Subverted in The Guns of Navarone. While Corporal Miller is explaining how his gear has been sabotaged he holds up his time pencils and says "75 grains of fulminate of mercury in each of them, enough to blow my hand off. And very unstable, very delicate." He then ruthlessly crushes them. Instead of exploding, they do nothing - the traitor removed the fulminate of mercury.
• In Horatio Hornblower, the narration occasionally throws in a reminder that black powder is incredibly dangerous to work with. The men in the powder room couldn't even wear nailed shoes for fear a spark would blow up the whole ship.
• Star Wars Expanded Universe:
  • A New Dawn features baradium bisulphate, used in thorilide mining. It's sarcastically nicknamed "Baby" by the miners who work with it, and is volatile enough that the pilots who fly the transports carrying it from Gorse to its moon Cynda, where the mining takes place, are nicknamed "suicide fliers". Oh, and then there's baradium-257, its radioactive and even more explosive cousin, nicknamed "Nasty Baby".
• Dungeon Crawler Carl: All explosives have a "stability" rating, and if it gets too low, it has a chance to randomly explode. This is usually more complex than just being "stronger explosives are less safe," though. Goblin dynamite is liable to explode if you so much as look at it wrong, but it's significantly weaker than the mostly stable hobgoblin dynamite, because goblins don't understand chemistry very much. When Carl starts creating custom explosives, how stable they are generally depends on how much time he was able to spend building them. A true prepared mine is very stable even before literal magic comes into play, but oftentimes Carl will just use an IED that's little more than a bunch of sticks of goblin dynamite taped together, because he doesn't need them to last more than a few seconds. It helps that he has an inventory system which doesn't affect stability.

Live-Action TV

• In 'Allo 'Allo!, chickens are accidentally fed grain laced with nitroglycerine (instead of gin). The hens explode one after another from the strain of egg-laying. The cockerel's attentions are sufficient to provoke the final hen into blowing up the hen house. The cockerel survives.
  Rene: You are looking at a living legend.
• In Breaking Bad, Walt throws a handful of mercury fulminate on the ground and it explodes, causing major damage to the room.
• Doctor Who: In "Pyramids of Mars", the Doctor and Sarah happen across a poacher's cache of old, unstable gelignite. Sarah casually tosses it to the Doctor, nearly giving him a hearts-attack, before he warns her of the danger. Because they can't find any fuses, Sarah has to shoot it with a rifle to detonate the explosive.
• The F.B.I.: In "Pound of Flesh", a pair of crooks have secured a thermos-sized container of nitroglycerine that they are intending to use to blow a safe. During a shootout with the FBI, a stray shot hits their car and it explodes.
• Foyle's War: One episode involves a munitions plant, where a young woman dies when she drops an incomplete shell and it explodes. Later, nitroglycerin is discussed as being impossible to steal not because of security but because it can't be moved without first rendering it inert—it's far too dangerous. When the culprit shakes a vial of it in front of Foyle at the end, it alerts Foyle that it's no longer explosive because it would have gone off just from that.
• The series premiere of Gemini Man had the hero transporting a sample of triplodine, a chemical that is allegedly a fuel additive that triples its efficiency, but quickly degrades into an explosive three times as powerful (and unstable) as nitroglycerine.
• Arzt from Lost dies when he waves a stick of TNT too roughly and it detonates in his hand. Ironically enough, he was in the middle of a lecture on how to handle dynamite safely.
• Subverted on MythBusters multiple times.
  • The myth that a defibrillator could cause a nitroglycerin patch to explode was soundly busted.
  • Despite what video games might have you believe, Exploding Barrels will not explode if shot with anything less than incendiary rounds from a Gatling gun!
  • A series of tests were conducted on detonating C4, nearly all of which subverted this trope. The C4 did not detonate when it was burned, stepped on, shot with a variety of bullets, crushed by an anvil, or even when placed under an ignited thermite charge. The only test in which it did detonate was when it was microwaved, but then only when a blasting cap was in place.
  • The Breaking Bad scene listed above was busted. When the mercury fulminate didn't detonate when thrown, the guest stars from the show tried to handwave by saying Walt had also used a bit of silver fulminate.
  • Another MythBusters example would be the claim that a binary explosive used in special effects work can be set off in a car wreck. Even assuming somebody was reckless enough to transport the explosive pre-mixed, the chemical is too stable to be set off in a wreck.
• Star Trek: The Original Series episode "Whom Gods Destroy". The madman Garth of Izar has developed an explosive so powerful that a single flask of it could vaporize a planet. It will go off if dropped to the floor.
• Star Trek: Discovery introduces isolynium, which is handled as carefully as nitro.
  Ruon Tarka: The Federation banned it for a good reason. A little goes a long way.

Tabletop Games

• Deadlands has rules for dynamite and nitro. Powerful weapons, but if a Player Character is hit while carrying them they have to do a special save or get blown up.
• Shadowrun: If a character is carrying grenades or plastic explosives and takes damage from a fire or lightning spell or effect, they must immediately make resistance checks for all the explosives they're carrying or have them explode. The character's armor rating doesn't apply to this check (making it nearly impossible to succeed under normal circumstances) unless they're specifically carrying the explosives under their armor. Though if they're doing that, failure becomes a bit more exciting. 'Runners who regularly carry explosives are prone to buying armored briefcases that are specially treated to resist fire and electricity.

Video Games

• In Angry Birds, if a bird, rock, piece of wood (anything, really) hits a box of TNT, it will blow up (even if there's no source of fire).
• The mines that you and your opponent can lay in a match of the Intellivision game Armor Battle can destroy both your tanks and your opponent's.
• In Cannon Fodder, shooting a box of grenades or a bundle of rockets with a single bullet will cause it to explode.
• The two Castlevania games on the Nintendo 64 have the item "Magical Nitro" which is used in conjunction with "Mandragora" to make an explosive that destroys cracked walls. However, the game cautions that the Nitro is extremely volatile; the player must avoid jumping or being hit by enemy attacks or else the Nitro explodes and instantly kills the character.
• Caves of Qud has Neutron Flux, which is relatively easy to collect once found, but once you have it cannot be handled without the right recipe or even just switched between containers without killing you and everyone nearby.
• Claw: Gunpowder barrels, if picked up and tossed by the Player Character, will explode when they touch the ground, no matter what their final velocity is. Zig-zagged in that they bounce harmlessly off the walls and ceiling.
• Crash Bandicoot has Nitro boxes that go off at the slightest touch. They also bounce randomly as an indication of how volatile they are. TNT is less sensitive than Nitro, as you can touch the side without dying. Hitting the top triggers a 3-second timer, but you can still get killed if you're nearby when it explodes... or if you try to spin it. In the fourth game, Kupuna-wa's time slow lets you safely touch Nitro crates, but you better hustle away from them because they will explode anyway.
• Deus Ex: Tossing a crate of TNT any significant distance will cause it to explode.
• All grenades and placed explosives in Fallout 3, Fallout: New Vegas, and Fallout 4 explode when shot, even C4. Unrealistic, but useful if you don't have a detonator—or want to get fancy and blow up an enemy's grenade in their hand.
  • During the NV DLC Lonesome Road, you can detonate the nuclear warheads you come across in The Divide with a special warhead detonator - which function as a laser pistol that makes the warheads glow until they burst. It's a little-known fact that nuclear weapons need to be triggered in an incredibly specific way in order to detonate; do it incorrectly and you just ruin the trigger mechanism. Though, given that the warheads don't obliterate everything in a five-mile radius (including the player character) might suggest that this is actually what happens.
• The Incredible Machine has a vial of nitro as an item. Any impact, even a fan blowing air against it, can set it off, except one. That's important in one level.
• Insurgency: Sandstorm: Both sides' remote explosives (C4 for Security, IEDs for the Insurgency) will detonate when shot. Whilst the IED is crudely made from artillery shells and probably would detonate from a gunshot, the C4 firmly falls into this trope (likely for balance purposes).
• Knuckles Chaotix has a Joke Character simply known as Bomb. Should he get hurt by anything, he'll explode on the player.
• In The Legend of Zelda: Majora's Mask, one sidequest involves stopping Sakon the Thief from stealing the Bomb Shopkeeper's wares. Shooting him with an arrow will set off the explosives, killing him and denying you the reward.
• Mafia II reminds you to drive carefully if the car is carrying explosives. They detonate on anything more than a common scratch.
• M.U.G.E.N: There's a Purposely Overpowered atomic bomb character that uses a One-Hit Kill explosion to attack (and doesn't kill itself doing so). It also explodes if the opponent hits it, or if it simply "jumps" and lands on the ground.
• In Penumbra: Overture, Philip LaFresque has to create Armstrong's Mixture to blow down a cave-in that Red is trapped behind. In order to do so, he has to carry a flask of the compound across several platforms and planks, and dropping it creates an instant explosion. Thankfully, Phillip automatically puts it safely in place at the actual cave-in.
• In Resident Evil, specifically the remake, you need to get an empty fuel cell, fill it, and put it into a machine to provide power to the secret lab under the mansion. However, the fuel cell can only be filled in one specific area, and has to be transported to another area, and it is extremely susceptible to shock: you cannot fire a gun, get hit, or run without risking an explosion. Considering the fact that several of the enemies in the area are Immune to Bullets and fast as hell to boot, it's an extremely tense moment, even if you only have to go through three rooms.
• Powder Boxes in Spelunky HD will explode violently when hit by anything, even by otherwise-harmless flying blood drops and shrapnel. Pushing, walking atop, or jumping on them over and over will not set them off; additionally, powder boxes will only explode if they fall more than one tile.
  Journal Entry: "It's filled with black powder. Handle with care!"

Web Comics

• Unsuccessfully invoked in the Homestuck Midnight Crew intermission by Clubs Deuce, who once wears a lump of C4 on his head before charging with his cane (apparently made from bovine attribute skin) in hand:
  Stitch says drop the livestock knob and settle the hell down. He says you do realize C4 is a stable explosive and won't detonate with gunfire, right? You say oh.
• The Whiteboard: Doc rips the door from a room containing about six tons of century old, leaky dynamite.

Western Animation

• In one episode of Aladdin: The Series, when Prince Uncouthma challenges Aladdin to a duel for the hand of his fiancee (It's a Long Story), the Evil Chancellr responsible for the mess substitutes the mallets used in the battle with hammer heads made of an extremely volatile cheese compound, ending to eliminate both Aladdin and Uncouthma. He advises his right hand yak to be careful as the slightest impact could set the mallets off. This poses a problem when the vizer and his yak get transported the traditional Odiferian way: by being tossed into the air.
• In The Fairly Oddparents, Timmy's Dad rubs 2 sticks of dynamite together trying to make a fire. The sticks explode instead.
• In Futurama, Fry is carrying sticks of dynamite, and each time one fell off it exploded. Fry makes it to the storage shed, there's a big explosion inside, and Fry emerges singed. Of course, the whole point of dynamite is that it doesn't explode unless detonated, so this was strictly Rule of Funny.
• In a first-season episode of G.I. Joe: A Real American Hero "Captives of Cobra", the Joes are trying to secretly transport highly volatile crystals which will explode if jostled too hard. Naturally, since Cobra discovers their route, Duke, Tripwire and Gung-Ho have to divert over an unpaved mountain pass while the rest of the team covers their escape.
• A recurring Looney Tunes gag has a character drinking a bottle of nitroglycerin and then either exploding or acquiring explosive saliva.
• The Simpsons: Zigzagged in "The PTA Disbands", a tour guide in Fort Springfield is giving a lecture on a "fully restored and in ready-to-fire condition" Civil War cannon aimed directly at the base of a manned lookout tower. She mentions that these cannons are "very sensitive and that the "slightest jolt" can set them off as the Springfield Elementary bus starts swerving towards the cannon. The bus hits it and... one of the cannon's wheels falls off.
  Tour Guide: Of course for safety reasons, we don't keep the cannon loaded. That's just common sense.
• During the ending of the Spongebob Squarepants episode "Dying for Pie", Spongebob shows Squidward that he never ate the bomb pie, he was saving it in his pocket the whole time. He then trips, dropping the pie and causing an explosion (a live-action nuclear one to be specific), and then it cuts back to Spongebob and Squidward, completely covered in ash from the explosion.
  Squidward: Ow.
  • Before that, a bite of that pie is enough to blow up Mr. Krabs' office when that hits the ground.

Real Life

• A website of Real Life stories, mostly from the 19th century: The Tallini Tales of Destruction. Many of them are of the form that truth is stranger than fiction.
• Pure nitroglycerin is extremely unstable and prone to exploding if roughly handled (the reason dynamite was invented was to make nitroglycerin safer to transport and use). However, by freezing nitro, it becomes very hard to blow up.
  • The chemist primarily responsible for creating Dynamite, in an effort to curb the sensitivity of Nitroglycerin, was Alfred Nobel, who hoped that the safer-to-handle explosives he created to stop people dying in mining and chemical factory accidents would also render warfare obsolete. That obviously didn't happen, and when his obituary was prematurely published after his brother died (of a heart attack, due to a heart condition for which he took Nitroglycerin) he was so horrified at being labelled "The Merchant Of Death" that he created the Nobel Peace Prize to try and change his legacy.
  • While newly made dynamite is safe, old dynamite is unstable because it "sweats" the nitro out of itself, which can then act as the triggering explosive to set the rest off.
  • Similarly, Medical nitroglycerin is, like blasting dynamite, made in a safe form factor (pills, patches, etc) and can't explode.
• Anyone who has seen the lab demonstration concerning how quickly and simply nitro can be made (if you have the correct chemicals) will remember the inevitable sequel for life. The test-tube, in which a very small quantity of nitro has been made, is held at arms-length by the demonstrator and then dropped. The impact imparted simply by dropping the damn thing causes a large bang and sends glass shards flying everywhere. (This was in the context of an Army lecture about improvised explosive devices and how simple explosives can be made from scratch. The instructors are usually experienced NCO's and officers who know how far they can go.)
• Another hair-trigger explosive is fulminate of mercury, which is used in blasting caps in order to set off other explosives and percussion caps for muskets in the mid-1800s.
  • And if you think fulminate of mercury is bad, then look at fulminate of silver. It can explode under its own weight.
• There are "contact explosives" (see The Other Wiki) that are almost ridiculously sensitive. Nitrogen triiodide, when dry, is so sensitive that being exposed to alpha radiation is enough to detonate it.
  • Nitrogen loves to be with itself, with a triple-bonded N2 compound being extremely strong compared to other bonds with nitrogen. So a lot of compounds made with nitrogen end up being contact explosives because comparatively speaking, any other bond is weak and easily broken.
• Acetone Peroxide compounds, most commonly Triacetone Triperoxide or TATP, were the explosives of choice among terrorist groups for quite a while, since they are basically the only remotely practical high explosives that do not involve nitrogen in any way, shape or form, and thus (until about 2015, at least) would not be detected by explosive-sniffing dogs or their technological equivalents. They are also notoriously touchy, earning themselves the nickname "Mother of Satan", and "can explode powerfully if subjected to heat, friction, static electricity, concentrated sulfuric acid, strong UV radiation or shock" according to the other wiki. In the aftermath of the 7/7 bombings in London, a writer at The Register remarked that one of the really remarkable things about the attack was that the small group of people involved had somehow managed to make and transport that much TATP without blowing themselves up in the process - and that since they had all now died in their attack, their surprising degree of chemical competence was not available to anyone planning future atrocities.
• Averted with C4 (which is famous for its stability and inability to go off w/out a blasting cap) and TNT (which is safe and sane; you can burn the stuff in a stove, and it won't explode, you need a detonator to explode TNT). Soldiers in the Vietnam War were known to light small pieces of it to heat up MREs. Also, high explosives used in military context are always rated for sensitivity to penetration from gunfire - needless to say, insensitive types are preferred and mostly used, so usually you can shoot a HE brick full of holes to no effect. Detonating charges, (blasting caps, fuses, etc.) on the other hand, are quite partial to blowing up when shot at.
• Some of the "Things I Won't Work With" category on Derek Lowe's In the Pipeline are included for this reason. One of the near-definite winners must be an at the time unnamed compound (nicknamed Azidoazide Azide and later officially named 1-Diazidocarbamoyl-5-azidotetrazole) synthesized from N-amino azidotetrazole (which on its own already qualifies), which exploded on every single attempt to move it elsewhere for testing, and whenever they tried to get an infrared spectrum on it. Shining an infrared light on it set it off. The guy in charge of these tests, Thomas M. Klapötke (who is practically the king of dealing with these kinds of ultra-sensitive compounds) had to give up on it, because he quite simply couldn't get any meaningful measurement out of it, other than the fact it exploded with ridiculous ease.
• In 2014, the British Army claimed that an entire group of insurgents in Afghanistan had been killed by a single bullet when a British sniper unknowingly shot a suicide bomb vest that one of them was wearing.
• Picric acid becomes a highly shock-sensitive explosive similar to nitroglycerin when dried out, and thus old jars of the stuff, occasionally seen in back rooms of school chem labs, must be handled and disposed of by the bomb squad. Over time, salt crystals form in the acid and the crystals break with explosive force super easily.
• Averted with nuclear weapons, which usually have a ton of safety mechanisms to prevent them from exploding.
  • In fact, one method of stopping an atomic bomb is to destroy it with another explosion. The fissile material in an atomic bomb is set off using a very precisely controlled explosion in order to put it under a huge amount of pressure so it will go supercritical. Another explosion will cause it to fail. It will still produce a big explosion and scatter radioactive material everywhere, which nowhere near as powerful as if it had gone off correctly, but much more of a radiological hazard with the fuel unspent now scattered far and wide, turning a nuclear bomb into a 'dirty bomb'.
• Celluloid, the most common early form of plastic, was derived from the same chemicals as guncotton (nitrocellulose), and therefore, in addition to easily catching fire, had a reputation for spontaneously igniting and detonating under shock, e.g. a billiard ball exploding when struck with the cue.

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