Nitroglycerin has been used as an explosive in a wide range of civilian and military applications, most famously as the active ingredient in dynamite for mining, tunneling, and large-scale demolition. Beyond dynamite, it serves as a critical component in smokeless gunpowder, artillery propellants, and even solid rocket fuel. Its explosive power comes from an almost instantaneous chemical decomposition that releases enormous volumes of hot gas, but that same power made it notoriously dangerous to handle in its raw liquid form, a problem that shaped more than a century of explosives engineering.
From a Turin Laboratory to the World’s Quarries
The Italian chemist Ascanio Sobrero first synthesized nitroglycerin in the mid-1840s by treating glycerol with a mixture of nitric and sulfuric acids.1PubMed. Nitroglycerin headache and nitroglycerin-induced primary headaches from 1846 and onwards: a historical overview and an update Sobrero quickly recognized that the oily liquid was violently explosive and was reportedly horrified by the destructive potential of his creation. For roughly two decades after its synthesis, nitroglycerin remained more of a scientific curiosity than a practical tool because nobody had figured out how to use it without getting killed in the process. The liquid could detonate from a modest shock, a drop onto a hard surface, or even exposure to moderate heat.
That changed in 1867, when Alfred Nobel patented dynamite. Nobel’s insight was simple but transformative: he mixed liquid nitroglycerin with kieselguhr, a porous, chalky sedimentary material, to create a paste that could be shaped into sticks and handled without the terrifying sensitivity of the pure liquid.1PubMed. Nitroglycerin headache and nitroglycerin-induced primary headaches from 1846 and onwards: a historical overview and an update The resulting product still packed an enormous punch but required a blasting cap to set it off, which meant that accidental detonation during transport and storage dropped dramatically. Dynamite became one of the most commercially successful inventions of the nineteenth century, and Nobel’s fortune from its sale eventually funded the Nobel Prizes.
Why Nitroglycerin Is So Powerful
Nitroglycerin’s explosive force comes from what happens when its molecules break apart. The compound contains carbon, hydrogen, nitrogen, and oxygen all packed into a single molecule. When it decomposes, it does so almost instantaneously, releasing carbon dioxide, water vapor, nitrogen gas, and oxygen. A tiny volume of liquid converts into a vastly larger volume of hot gas in microseconds. That sudden expansion is the blast wave you feel and hear. The speed of the reaction is what distinguishes a detonation from an ordinary fire: the decomposition front travels through the material faster than the speed of sound in the surrounding medium, creating a supersonic shock wave.
What makes nitroglycerin particularly effective compared to many other explosives is that it carries its own oxygen supply within its molecular structure. It does not need to pull oxygen from the air to sustain the reaction, so it can detonate underground, underwater, or in any confined space. This self-oxidizing property is one reason it became indispensable for mining and tunneling, where other energy sources would struggle.
Dynamite and Civilian Blasting
The single largest use of nitroglycerin as an explosive, historically, has been in dynamite and related commercial blasting products for mining and construction. From the 1870s onward, dynamite was the go-to explosive for breaking rock in quarries, excavating tunnels, cutting railroad passes through mountains, and clearing land for major infrastructure projects. Nitroglycerin is described as the main component of high explosives such as dynamites and as an ingredient in most mining explosives.2Process Safety and Environmental Protection. The kinetic parameters and safe operating conditions of nitroglycerine manufacture in the CSTR of Biazzi process
The scale of some of these projects is hard to overstate. The construction of the Panama Canal, one of the largest engineering undertakings of the early twentieth century, consumed staggering quantities of dynamite to cut through the mountainous continental divide. Railroad expansion across the American West, hard-rock gold and silver mining, and the excavation of subway systems in major cities all depended on nitroglycerin-based explosives. Before dynamite, rock-breaking relied on black powder, which was far weaker and slower, or on brute manual labor with picks and drills. Dynamite compressed weeks of work into seconds.
Over the twentieth century, the mining industry gradually shifted toward other explosives, particularly ammonium nitrate and fuel oil mixtures, which are cheaper to produce, more stable in storage, and less sensitive to accidental detonation. Nitroglycerin-based dynamite is still manufactured and used today, but its share of the commercial blasting market is far smaller than it once was. It tends to appear in specialized applications where its particular detonation characteristics are needed, rather than in bulk blasting.
Military Propellants and Munitions
Nitroglycerin’s role in military technology has been just as significant as its role in mining, though less well known to the general public. When combined with nitrocellulose, nitroglycerin forms what is called a double-base propellant, a formulation used extensively in smokeless gunpowder. This replaced the older black powder in firearms and artillery during the late nineteenth and early twentieth centuries, giving militaries a propellant that burned more consistently, generated less smoke on the battlefield, and produced higher muzzle velocities.2Process Safety and Environmental Protection. The kinetic parameters and safe operating conditions of nitroglycerine manufacture in the CSTR of Biazzi process
Adding a third ingredient, nitroguanidine, creates a triple-base propellant, which has been used in larger-caliber artillery projectiles. Triple-base propellants burn at a lower temperature than double-base formulations, which reduces barrel erosion in big guns, extending the life of expensive artillery pieces. Nitroglycerin has also been used as an ingredient in solid propellants for rockets, where its high energy density per unit mass is valuable for generating thrust.
In all of these military applications, nitroglycerin is not detonating the way it does in a stick of dynamite. Instead, it is undergoing a controlled, rapid burn called deflagration, where the reaction front moves through the material at subsonic speeds rather than supersonic ones. Propellant chemists carefully formulate the mixture so that the burn rate is fast enough to generate useful gas pressure inside a gun barrel or rocket motor but slow enough that the weapon does not simply explode. Getting that balance right is one of the core challenges in propellant engineering, and the proportion of nitroglycerin in the mix is one of the main variables that determines burn behavior.
The Sensitivity Problem
Raw nitroglycerin in liquid form is extraordinarily sensitive to mechanical shock, friction, and heat. This sensitivity is both what makes it useful and what makes it dangerous. A jar of the liquid dropped from waist height onto a hard floor can detonate. Workers in early nitroglycerin factories faced constant risk, and catastrophic accidents were common in the decades before Nobel’s dynamite and later stabilization methods became standard. Entire factories were destroyed in single incidents, sometimes killing dozens of people.
The physics behind this sensitivity involves a phenomenon called hot-spot initiation. When a shock wave passes through liquid nitroglycerin, small gas bubbles trapped in the liquid collapse violently. Research using high-speed photography has shown that the collapse of even a few gas bubbles just a few cubic millimeters in volume can locally accelerate the burning rate and generate pressure pulses strong enough to create additional hot spots at nearby cavitation sites.3Combustion and Flame. The sensitisation of thin films of nitroglycerine When multiple bubbles are present, these effects compound: each collapsing bubble can trigger further collapses nearby, and the chain reaction can escalate from a localized burn into a full detonation. This is known as a distributed hot-spot model, and it explains why even a relatively mild mechanical disturbance can set off the liquid.
Nobel’s dynamite addressed this problem by absorbing the liquid into an inert solid matrix, but later formulations went further. Gelatin dynamites mixed nitroglycerin with nitrocellulose to form a gel that was even more resistant to accidental initiation while retaining high explosive power. Modern nitroglycerin-based products are engineered with careful attention to the size and distribution of any voids or gas pockets in the material, precisely because of the hot-spot mechanism.
How Nitroglycerin Is Manufactured for Explosive Use
Making nitroglycerin involves reacting glycerol with a mixture of concentrated nitric and sulfuric acids, a process called nitration. This is inherently hazardous because the product is an unstable explosive being formed in the presence of strong acids and heat. The reaction is highly exothermic, meaning it generates heat, and if the temperature is not carefully controlled, the batch can detonate during production.
Modern industrial manufacturing of nitroglycerin for explosive use typically relies on continuous-flow reactor systems rather than the older batch processes. The Biazzi process, developed in the mid-twentieth century, uses a continuous stirred-tank reactor where glycerol and mixed acid are fed in at controlled rates, and the product is continuously drawn off and washed. Careful monitoring of kinetic parameters and temperature is critical to maintaining safe operating conditions during manufacture.2Process Safety and Environmental Protection. The kinetic parameters and safe operating conditions of nitroglycerine manufacture in the CSTR of Biazzi process The continuous-flow approach reduces the amount of explosive material present in the reactor at any given moment, limiting the consequences of an accident. Even so, nitroglycerin manufacturing plants operate with extensive safety protocols, including blast-resistant walls between production stages and remote-controlled operations wherever possible.
Forensic Detection After an Explosion
When investigators arrive at the site of a bombing or industrial explosion, one of the first questions is what type of explosive was used. If nitroglycerin was involved, traces of it and its decomposition products will be scattered across the blast debris. Forensic chemists can detect nitroglycerin at extremely low concentrations, down to nanogram-level quantities, using laboratory techniques that separate and identify the compound from a complex mixture of post-blast residue. Even after the enormous temperatures and pressures of a detonation, small amounts of unburned or partially decomposed nitroglycerin persist on surfaces near the blast seat, embedded in soil, or deposited on fragments of the device casing.
This forensic capability matters because identifying the explosive tells investigators a great deal about the likely source. Nitroglycerin-based explosives point toward commercial dynamite or military-grade propellants, narrowing the field of suspects and supply chains. The analytical sensitivity has improved over the decades, meaning that older cold cases involving nitroglycerin-based devices can sometimes be revisited with modern detection methods that were not available at the time of the original investigation.
Where Nitroglycerin-Based Explosives Stand Today
Nitroglycerin is no longer the dominant commercial explosive it was in the late 1800s and early 1900s. For large-scale mining and quarrying, cheaper and safer alternatives like ANFO (ammonium nitrate mixed with fuel oil) and emulsion explosives have taken over the bulk of the market. These alternatives are less powerful per unit weight than nitroglycerin-based dynamite but are dramatically cheaper to produce, far more stable during storage and transport, and much less likely to detonate accidentally.
That said, nitroglycerin has not disappeared. It remains in use in specialized applications where its particular combination of high detonation velocity, high energy density, and well-understood performance characteristics are needed. Certain types of hard-rock mining, underwater demolition, and military propellant formulations still rely on it. The double-base and triple-base propellants that power many conventional munitions continue to include nitroglycerin as a core energetic ingredient. And in the rocket propulsion world, some solid-fuel formulations still incorporate it.
The long-term trend is clear, though. The explosives industry has spent more than a century finding ways to get comparable blasting results from materials that are less finicky to handle. Nitroglycerin’s sensitivity, the same property that made it so devastating and so useful, is also what has driven its gradual replacement in applications where safety margins and cost matter more than peak performance.
The Surprising Medical Afterlife
One of the stranger chapters in nitroglycerin’s story is its second career as a heart medication. Workers in dynamite factories in the nineteenth century noticed that they developed severe headaches during the work week that went away over weekends, only to return on Monday. Physicians eventually realized that nitroglycerin vapor was dilating blood vessels, which caused the headaches but also suggested a therapeutic use for people with angina, the crushing chest pain caused by restricted blood flow to the heart.1PubMed. Nitroglycerin headache and nitroglycerin-induced primary headaches from 1846 and onwards: a historical overview and an update
The English physician William Murrell described the benefits of nitroglycerin for angina pectoris in 1879, just a dozen years after Nobel patented dynamite.4PubMed. Explosive discovery, surprising future: The extraordinary journey of nitroglycerin, nitroderivatives and nitric oxide The doses involved are vanishingly small compared to explosive quantities, typically fractions of a milligram delivered as a tablet dissolved under the tongue or as a skin patch. At those doses, the compound releases nitric oxide in the body, which relaxes smooth muscle in blood vessel walls, widening the arteries and easing the heart’s workload. It remains one of the most commonly prescribed treatments for acute angina episodes today, more than 140 years after Murrell’s initial reports.
The irony was not lost on Alfred Nobel himself. In one of the more frequently quoted anecdotes in the history of chemistry, Nobel reportedly remarked late in life that his doctors had prescribed nitroglycerin for his own heart condition. “They call it Trinitrin, so as not to scare the pharmacist and the public,” he is said to have written to a friend. Whether or not the quote is perfectly accurate, it captures the genuine strangeness of a compound that shaped both the explosives industry and modern cardiology.