The ground shook 15 miles away. Birds fled, windows rattled, and residents described a sound like a bomb going off. On Friday evening, a fire at an industrial unit in Essex triggered a fertiliser explosion that sent 20 firefighters to hospital and destroyed three fire engines. The blaze, which prompted a major incident declaration and the evacuation of nearby homes, is a stark reminder of how dangerous agricultural chemicals can be when they catch fire.
At its simplest, a fertiliser explosion happens when heat from a fire causes certain fertilisers—particularly those containing ammonium nitrate—to decompose rapidly, releasing gases that expand violently. In the Essex incident, the fire broke out at a unit on Southend Road, between East Hanningfield and Rettendon, at around 4.50pm. Approximately 100 firefighters from Essex County Fire and Rescue Service were deployed. The blaze spread across several industrial units and an adjacent field, and the fertiliser inside one of the units exploded while crews were on the scene. Chief fire officer Rick Hylton confirmed that 20 firefighters attended hospital—four with minor injuries, the rest for precautionary checks, including hearing tests. All have since been discharged. The explosion also destroyed three fire engines and two officer cars, underlining what Hylton called "the scale and intensity of the conditions our crews faced."
“A fertiliser explosion in Essex sent 20 firefighters to hospital—explaining why these blazes happen and the risks to UK communities.”
Fertiliser explosions are not new. Ammonium nitrate, a common ingredient in fertilisers, has been involved in devastating industrial accidents worldwide—most famously the 2020 Beirut port explosion and the 1947 Texas City disaster. In the UK, regulations have tightened after incidents such as the 2001 explosion at a fertiliser plant in Toulouse, France, and the 2005 Buncefield oil depot blast, which prompted reviews of hazardous substance storage. The Health and Safety Executive (HSE) classifies ammonium nitrate as a dangerous substance, and its storage is subject to strict rules under the Control of Major Accident Hazards (COMAH) regulations. However, smaller agricultural stores may not always fall under the highest tier of regulation. The cause of Friday's fire is still under investigation, and Hylton has urged people not to speculate.
For UK readers, this event matters because it highlights a very real risk in rural and semi-rural areas. Farms and small industrial units that store fertiliser are dotted across the country. While major incidents are rare, the consequences for nearby residents—evacuation, smoke plumes, potential structural damage—can be severe. Firefighters face heightened danger when responding to such fires, as the sudden explosion of stored chemicals can turn a routine call into a life-threatening situation. The destruction of fire engines also raises questions about the adequacy of protective measures and the need for better pre-planning for fires at sites with hazardous materials.
Q: Can any fertiliser explode? Not all fertilisers are explosive. The risk is highest with ammonium nitrate-based fertilisers, especially when they are contaminated with organic materials or subjected to intense heat. Most garden fertilisers sold in small quantities are safe, but bulk agricultural storage can become hazardous in a fire.
Q: Why were firefighters hospitalised if only four were injured? The other 16 firefighters were taken to hospital for precautionary checks, primarily for potential hearing loss or exposure to smoke and chemicals. Standard protocol after a large explosion often involves medical screening even if no visible injuries are present.
Q: How close do you have to be to a fertiliser explosion to feel it? Residents 15 miles away—such as Adrian Walker from Ashenden—reported the ground shaking and windows rattling. The blast wave from a large fertiliser explosion can travel for miles, depending on the quantity of material and the conditions.
What happens next: Essex County Fire and Rescue Service has launched a formal investigation into the cause of the fire and explosion. Firefighters remain at the scene to deal with hotspots and begin the recovery phase. The HSE may also investigate whether COMAH regulations were fully complied with. Local roads are still closed, and residents are asked to avoid the area. The incident will likely prompt renewed scrutiny of fertiliser storage safety across UK farms and industrial units.