In some laboratories, a clear, oily liquid is treated less like a reagent and more like contraband, locked away behind blast doors and handled with rituals that look closer to bomb disposal than bench science. The reason is simple: a few drops in the wrong place, at the wrong temperature, can turn a quiet lab into a crater. That same liquid, and others like it, are so energetic and so sensitive that researchers have learned to treat them as if they were weapons.
What makes these liquids uniquely unnerving is not just the violence of their explosions but the ordinariness of their appearance. They look like solvents or medicines, yet a stray hammer blow, a warm water bath, or a contaminant can trigger a runaway reaction that no one in the room can outrun.
Nitroglycerine, the original liquid nightmare
The archetype of this class is Liquid Nitroglycerine, a colorless, oily material that can sit quietly one moment and detonate from a modest shock the next. In its undiluted form, nitroglycerin is a contact explosive, which means that physical impact or friction can be enough to set off a devastating blast, a property that has made it both a powerful industrial tool and a constant source of dread for anyone who has to move or store it. Chemists learned early that even gentle warming can be risky if the temperature rises too quickly, because the liquid decomposes and releases gases faster than they can escape, turning a flask into a bomb.
That hair-trigger behavior is why modern labs keep nitroglycerin in tiny quantities, heavily diluted and locked away, and why historical accounts of its early use read like accident reports. One detailed overview of liquid explosives notes that nitroglycerine was first discovered in 1846 and quickly gained a reputation for catastrophic mishaps during transport and handling. Even today, guidance on nitroglycerin emphasizes that undiluted material is so sensitive that only specialized facilities are allowed to work with it at scale.
From dynamite to heart medicine
The paradox that fascinates chemists is that this same volatile liquid can be tamed into something life saving. When Alfred Nobel learned to absorb nitroglycerine into an inert material to make dynamite, he turned a dangerously mobile liquid into a more manageable solid, yet the underlying explosive power remained. A later retelling of his early career describes how Alfred, at the age of 17, found himself in a lab in Paris studying under leading chemists, where he encountered nitroglycerine and began the work that would eventually link his name to both explosives and peace prizes, a dual legacy that still shapes how I think about this compound.
Medicine added another twist by discovering that tiny doses of nitroglycerin relax blood vessels and relieve chest pain, so the same substance that can shatter rock can also open clogged arteries. A popular science explainer on why nitroglycerine is walks through how its dense packing of oxygen and nitrogen atoms makes it far more energetic than gunpowder, while a separate video on its role as an explosive heart medication shows doctors dispensing it in microgram doses. That split personality is why labs treat bulk nitroglycerine like a weapon, even as hospitals keep carefully controlled vials in crash carts.
Why labs fear crystals, hammers and warm water baths
In practice, what terrifies safety officers is not just the chemistry on paper but the mundane ways things go wrong. When old nitroglycerin sits undisturbed, it can form microscopic crystals that lodge on container walls or in residues, turning a once homogeneous liquid into a minefield of tiny, rigid grains. A demonstration clip of a nitroglycerine detonation filmed in slow motion includes a veteran who says he worked 30 years at the largest Ammunition Plant in the United States, making thousands of pounds of NG daily using the Biazzi process, and he stresses that even with that experience, the material is very dangerous as well, a reminder that familiarity does not erase risk.
Those crystals are why technicians are trained never to scrape dried residues and why even a simple hammer becomes a potential detonator. In another widely shared segment, Adam Savage triggers a nitroglycerin explosion with a hammer while viewers are warned in the Comments that When old nitro starts to crystallize and those microscopic crystals rub against each other, that is when it starts getting truly unstable. That clip, linked through a short hammer test, captures why labs lock such liquids away and impose strict aging limits, disposal rules and inspection routines that treat every crusted cap as a potential bomb.
Other liquids that behave like hidden weapons
Nitroglycerine is not alone in forcing labs to think like armories. Guidance for hazardous chemicals singles out Diazomethane, a yellow gas that is often handled in solution, as a substance that requires extreme caution because They are very toxic and, in pure form, can detonate from heat, light or rough surfaces. That same safety manual also warns that Benzoyl Peroxide (C6H5CO2)2 is easily ignited and sensitive to shock, and that it decomposes spontaneously at temperatures above 50°C (122), a combination that turns a warm storage cabinet into a potential ignition source if someone forgets to check the thermostat.
Even compounds that are better known as fuels can cross the line into weapon territory under the wrong conditions. Nitromethane, for example, is famous in drag racing circles as a high energy fuel, but a detailed technical history notes that Nitromethane was first prepared in 1872 by Kolbe and was long considered very stable until chemists learned that it can detonate when contaminated with bases, amines or exposed to elevated temperatures. Modern hazard sheets classify Nitromethane as a FLAMMABLE LIQUID and specify to Use CO2, water spray or alcohol resistant foam to fight fires and NOT dry chemical agents, while a racing oriented explainer on Nitromethane walks through how small formulation mistakes can turn a fuel tank into an explosive charge.
Security, terrorism and the case for locking the door
The security dimension is what finally pushes these liquids into the same mental category as weapons. A survey of liquid explosives notes that among the materials of concern to anti terrorism officials are Triacetone triperoxide, often abbreviated TATP, and that British security services have had to treat even small precursor purchases as potential red flags. That same analysis points out that nitroglycerine and related compounds are within reach of dedicated terrorists, which is why regulators have tightened controls on sales of concentrated nitric acid and other feedstocks that could be diverted from labs to illicit workshops.
Inside research institutions, those external threats translate into locked cabinets, inventory audits and strict training. Safety manuals from major universities spell out that Diazomethane solutions must be prepared behind shields, that Benzoyl Peroxide must never be heated above 50°C (122) without engineering controls, and that any unexplained crust or discoloration on a container is grounds for evacuation and professional disposal. One such manual on Benzoyl Peroxide and another on broader laboratory safety both treat these liquids as if they were improvised explosives waiting for a trigger. Historical context from Nobel’s own foundation underscores that Nitroglycerine is an explosive liquid so sensitive that it had to be turned into a paste to be handled safely at scale, a lesson that modern labs have absorbed by locking the raw liquid away and treating every milliliter as if it were a loaded device.
More from Morning Overview