From Minneapolis to Tianjin: How explosion disasters influenced safety standards

Explosions in industrial plants have not only caused devastating damage, but have also triggered far-reaching changes in safety regulations, technology and risk awareness. At POWTECH TECHNOPHARM, leading companies present innovative solutions for fire and explosion protection – from preventive sensor technology to modern extinguishing and relief systems. This article looks back at the biggest explosion disasters in industrial history and shows how they continue to shape technology and safety standards to this day.

Written by Armin Scheuermann

Löscharbeiten an der brennenden Ölbohrplattform Deepwater Horizon — Safety technology and explosion protection are characterised by fire and explosion disasters such as the Deepwater Horizon accident.

The history of industrial explosion protection is, above all, a history of disasters. The fact that combustible gases and dusts pose a hazard was already known from mining – but the ‘big bang’ in industrial production probably occurred in the USA in 1878: on 2 May 1878, the first documented dust explosion occurred in Minneapolis with devastating consequences. The Washburn A-Mill, at that time the largest flour mill in the world, was completely destroyed by a massive flour dust explosion. The cause was swirling dust, which was probably ignited by a spark or an overheated machine. The explosion killed 18 people and destroyed several neighbouring mills. As a result, technical measures to prevent dust explosions were introduced for the first time: dust extraction systems, regular cleaning and spark prevention. This disaster is considered the starting point of systematic dust explosion protection.

However, the Courrières mine disaster, which occurred three decades later in 1906 in the French coal mine Courrières, was much more serious: mine gas and coal dust led to an explosion that claimed the lives of over 1,000 miners. Poor ventilation, inadequate dust control and outdated technology contributed to the disaster. The disaster triggered a wave of reforms in European mining: methane sensors, improved ventilation systems and dust-reducing measures were subsequently introduced. The Courrières mine provided a drastic illustration of how dangerous dust and gas mixtures can be in closed systems – a central topic of modern explosion protection.

The Boston Molasses Disaster (1919, USA) was not a classic explosion, but the disaster in Boston revealed fatal safety gaps in the design of industrial storage tanks. A poorly constructed and maintained molasses tank at the Purity Distilling Company suddenly burst, releasing a flood of about 8.7 million litres of hot, viscous molasses. The approximately 4.5-metre-high wave rushed through the surrounding streets at an estimated 55 km/h. The result: 21 people drowned or were killed by debris, houses were swept away, and streets destroyed. The incident triggered one of the first class-action lawsuits against companies and led to the introduction of static calculations, material testing and mandatory safety inspections for large industrial containers. An early example of engineered prevention through structural safety.

Explosionskrater im Werk Oppau der BASF — In September 1921, a fertiliser silo belonging to the chemical company BASF exploded in Oppau.

Fertiliser explosion in Oppau: a wake-up call for the chemical industry

A spark in the literal sense of the word finally led to a rethink in German industry: in 1921, several thousand tonnes of an ammonium nitrate fertiliser mixture exploded at the BASF plant in Oppau (Ludwigshafen) – 560 people died and thousands were injured. Until then, the material had been considered relatively safe. The explosion showed that even seemingly stable substances can have catastrophic consequences if handled improperly. The disaster was a wake-up call for the chemical industry. It led to scientific research into ammonium nitrate and to the first safety guidelines for its storage, for example with regard to moisture, mixing and ignition sources.

Nitrates have always been suitable for both civilian and military use as ‘dual-use’ products. And they pose corresponding risks. In 1944, a huge stockpile of munitions detonated at the Port Chicago naval base, killing 320 people. The incident revealed major flaws in the handling of hazardous materials: untrained personnel, time pressure and a lack of standards. The incident led to the introduction of better safety protocols in the military and civilian hazardous materials sector, including in the training of personnel and the use of explosion-proof equipment. But the learning curve was not steep enough, because just three years later, in 1947, the next devastating explosion occurred in the United States: a ship loaded with ammonium nitrate exploded in Texas City, triggering a chain reaction. Over 600 people died. The explosion led to stricter regulations worldwide for the handling of ammonium nitrate. Temperature monitoring, special storage conditions and safe packaging methods were introduced. The transport of hazardous goods was also reformed – labelling, documentation and safety distances were reorganised.

But industrial disasters are a global phenomenon. In 1974, for example, a reactor exploded in a chemical plant in Flixborough, UK, because an improvised pipe connection had broken, presumably due to vibrations or thermal expansion. A large amount of hot, pressurised cyclohexane suddenly escaped and mixed with the air, forming an explosive gas-air mixture. The explosion killed 28 people. Flixborough became a prime example of the need for technical integrity and formalised safety procedures. As a result, systematic risk analysis was made mandatory by law in the UK. At the EU level, the accident provided an important impetus for the subsequent Seveso Directive.

The disaster at Seveso in northern Italy in 1976 was one of the worst accidents in the history of the chemical industry and led to the Seveso Directive, a key EU regulation for the protection of the public and the environment from the hazards of major industrial accidents involving dangerous substances. Although not an explosion in the traditional sense, a chemical accident released large quantities of toxic dioxins. The resulting Seveso Directive (now Seveso III) requires industrial plants in the EU to implement comprehensive safety concepts, emergency plans, risk analyses and information for the public – a milestone in preventive explosion and hazard protection.

The Piper Alpha explosion of 1988 is also seared in the memory of safety officers in the petrochemical industry to this day. On the drilling rig of the same name in the North Sea, a gas leak caused a devastating explosion that killed 167 people. After the disaster, offshore safety standards were reformed worldwide. Automatic emergency shutdowns, fireproof separation systems and blowout preventers (safety valves for drilling) were introduced. The safety culture was also strengthened: today, operators must present so-called ‘safety cases’ – comprehensive safety certificates before commissioning. The importance of these measures was dramatically underlined once again by the BP disaster in the Gulf of Mexico in 2010, where an explosion also occurred due to the failure of a blowout preventer. The disaster on the Deepwater Horizon platform claimed eleven lives and caused one of the most serious environmental disasters in the history of the oil industry – and made it clear that, despite existing safety regulations, their consistent implementation remains crucial.

Zerstörte Gebäude im Hafen von Beirut — Improper storage of fertiliser led to the Beirut explosion in 2020.

Combustible dust is often underestimated

While awareness of the risk of explosion from gas-air mixtures has been heightened by painful experience, dust often remains an abstract hazard. The fact that this is too simplistic a view was once again made clear in 2008 in Georgia, USA. In an Imperial Sugar plant in Port Wentworth, sugar dust, an everyday but combustible material, exploded. As a result of a series of detonations that spread from the packaging hall through the plant, 14 people died. This dust explosion led to a drastic tightening of regulations for the food industry in the USA. Technically, extraction systems, explosion suppression and regular cleaning became mandatory.

The Tianjin explosion is also likely to be fresh in the minds of many: in 2015, huge quantities of chemicals exploded in a port warehouse in the Chinese city, claiming over 170 lives. The disaster revealed global weaknesses in the management of hazardous materials. In China, new safety zones were defined, permits tightened and the storage conditions for hazardous substances revised. The issue was discussed anew internationally, particularly the proximity of hazardous storage facilities to residential areas.

The improper storage of fertiliser also led to the Beirut explosion in 2020, in which a warehouse containing 2,750 tonnes of ammonium nitrate exploded in the middle of the city. Over 200 people were killed and the city centre was destroyed. The ammonium nitrate had been stored for years without any safety measures. The issue of hazardous materials storage was reassessed worldwide: safety distances, storage duration, regular inspections and transparency came into focus. Some countries tightened their regulations, while others discussed international standards.

Technical innovations in response to disasters

All of the disasters mentioned led to specific technical developments. Here is a selection:

Explosion venting systems: protective flaps and membranes that allow pressure to escape in a controlled manner.
Inerting: use of nitrogen or CO₂ to displace oxygen.
Explosion suppression systems: sensors detect pressure increases and trigger extinguishing agents.
Methane and dust sensors: Permanent monitoring of critical parameters.
Anti-spark technology: Detection and shutdown of ignition sources in dusty areas.
Safe tank and storage designs: Static calculations, pressure-relieved structures and temperature-resistant materials.
AI-supported firefighting: Intelligent control of extinguishing agents and evacuation processes.

Conclusion: explosion protection is always reactive and preventive

The history of explosion protection is characterised by tragic accidents – but also by technological progress and regulatory milestones. Each disaster revealed weaknesses, which engineers, legislators and safety officers used to develop new measures. Today's state of the art in explosion protection is based on a historical foundation of pain, learning and innovation. At POWTECH TECHNOPHARM, it will be shown how modern technology, smart systems and well-thought-out concepts are helping to prevent such disasters today.

Author

Armin Scheuermann

Chemical engineer and freelance specialised journalist