July 21st 1992 Allied Colloids, Brighouse Road Low Moor, Bradford
Plan of the site
On the morning of the incident steam heated blowers in the warehouse had
been turned on to dry out moisture. It is thought that a steam condensate
line was responsible for heating a number of AZDN kegs, which were stored at
height in the No. 2 oxystore. The heating effect caused two or three of the
AZDN kegs to rupture and spill white powder all over the floor. A passing
employee thought that the powder was smoke and raised the alarm. It was
determined that no immediate hazard was present and the AZDN data sheet was
referred to before a clean up plan was devised. While waiting for
confirmation from the appropriate vacuum cleaner manufacturer an employee
noticed a plume of smoke/vapour and a hissing noise coming from a bag of SPS
that was located underneath the AZDN kegs. Before the employee could douse
the SPS with water the vapour plume ignited and became a jet flame of about
300 mm in length. Within a few seconds the jet flame became a flash fire
which was transmitted all around the room. The fire spread throughout the warehouse and smoke was blown towards
At 1420 h on Tuesday 21 July 1992 a series of explosions leading to an intense fire broke out in a storeroom in the raw materials warehouse of Allied Colloids Ltd, Cleckheaton Road, Low Moor, Bradford, West Yorkshire. The fire spread rapidly to the remainder of the warehouse and external chemical drum storage.
The Fire service was called at 14:22 h and the first appliance arrived from the local Odsal Fire Station (47) with Station Officer Cowling in charge by 14:28 h. Thick black smoke and flames were escaping from the roof in the vicinity of the storeroom and the quantity of smoke rapidly developed as the fire gained a swift hold, spreading to the external drum storage at X Bay. A 25 km/hr wind was blowing at ground level from slightly north of west (280°) causing the black cloud of smoke to drift eastwards, affecting the traffic flows on the M606 and M62 over two miles away. Eventually the smoke could be seen from Leeds City Centre, some 16 km away. The site emergency plan was activated and employees Following the arrival of the first fire-fighting appliance at 1428 h more appliances came until at the peak of the incident there were 36 fire appliances and 173 firefighters led by the Deputy Chief Fire Officer Saunders. Considerable difficulties were experienced in obtaining an adequate water supply as the water mains in the area were incapable of supplying the fire-fighting needs of a large fire. The company had been aware of this and there had been discussions with the fire service but a suitable alternative had not been provided. Water was obtained from Royds Hall Dam (900 m to the west) and Rigbys Wire Works (500 m to the north east). Foam was also used at the fire, including all of the stocks held by the company.
The fire was preceded by the rupture of two or three containers of azodiisobutyronitrile (AZDN) about 50 minutes earlier. These were kept at high level in a storeroom within the raw materials warehouse and as far as can be determined were accidentally heated by an adjacent steam condensate pipe. AZDN is unstable when heated and has a self-accelerating decomposition temperature (SADT) in 25 kg packages of 50°C. It is a flammable solid and incompatible with oxidising materials. HSE's investigation team concluded that powder released from rupturing drums came into contact with sodium persulphate and possibly other oxidising agents which were stored in the storeroom, causing delayed ignition followed by explosions and the subsequent major fire.
It had been described by Station Officer Cowling as the " D Day landings of Firefighting".
Fire officers had made early contact with the company's incident controller and had strongly advised the sounding of the emergency siren provided by the company to warn the public and employees in the event of a major accident. This advice was initially not acted upon. However further discussion and the continued escalation of the incident led to the siren being sounded at 1455 h.
Several fork-lift trucks and a lorry loaded with 16 tonnes of n-butyl acetate, a highly flammable liquid, were destroyed. An empty solvent road tanker standing outside the warehouse without a driver when the fire started was moved at an early stage and did not become involved in the conflagration. Residents reported burning fragments being lifted by the updraft falling on neighbouring property. None of these started any further fires. The serious potential for escalation of the incident was evidenced by numerous plastic drums on the fire block which were damaged by radiant heat. The fire service made a considerable effort to cool these containers of flammable liquids during the course of the fire and successfully prevented their ignition.The fire was finally contained at about 1740 h. Power was restored to the site at 2045 h, which enabled the siren to be sounded to stand down the emergency, but this caused some initial confusion to those on site and to some members of the public. Police control received an emergency call at 1428 h and an officer was despatched from Odsal Police Station at 1432 h. He quickly requested reinforcements and public address cars were requested at 1517 h and deployed at 1522 h. These toured the area, warning residents to stay indoors and close windows and doors.
Shortly after the fire it was reported that 33 people had been taken to Bradford Royal Infirmary, including approximately 20 fire service staff. Six were admitted and kept in overnight, including two police officers. One officer, who had been directing traffic at the junction of Cleckheaton Road and New Works Road, directly in the path of the smoke, was subsequently absent from work for four months and one year later had still not made a full recovery.
The blaze at Allied's Bradford headquarters destroyed its main
warehouse , but as it was brought under control chemicals
leaked into nearby rivers. A spokeswoman for the National Rivers Authority in Leeds said: 'There
has been a serious amount of damage and destruction to invertebrate
life in the River Calder.' She added that some fish had died, and while the pollution was
thinning as it travelled downstream, there was risk of damage to the
River Aire and the Humber. The company estimates the damage at around £6m, and said it had third-party insurance to cover pollution damage.
The fire at Allied Colloids in July 1992 resulted in considerable environmental damage to the local Aire and Calder rivers, largely due to firefighting activities. The incident highlighted a number of contributory shortcomings both in technical/safety precautions and FEHM measures including management of firefighting run-off. The incident occurred at one of the company’s raw materials warehouses. The warehouse had two rooms in which oxidising as well as flammable products were kept without proper segregation. The fire was probably caused by impact ignition following loss of containment of the incompatible materials. Although the Fire Brigade contained the fire on the same day, standdown was not possible until 18 days later due to the risk of re-ignition. During three hours of fi refi ghting effort, an estimated 16 million litres of fi rewater was used. Some of this water reacted with materials in the warehouse to form viscous polymers, which blocked the site drainage systems. There were also difficulties in maintaining continuous operation of pumps, with the result that firewater could not drain off in a controlled manner, and spilled into local waterways. An estimated 20,000 fish were killed, with significant pollution downstream of the incident.