Low Moor, Bradford

On 21 August 1916 when the eyes of the world were concentrated on the titanic struggle in The Somme, there occurred at Low Moor, Bradford one of the most awful industrial disasters ever, in this country. This took place at the premises of the Low Moor Munitions Company, formerly the Low Moor Chemical Company, situated at the bottom of New Works Road, where picric acid, used in the making of high explosives, was being manufactured in large quantities. Efforts were made by the works fire brigade to bring a fire under control, but to no avail. The first of the Bradford firemen to arrive came from Odsal station and were later joined by 18 men from Central. A tremendous explosion occurred which blew them completely off the engine and, in the words of Chief Officer Scott:

within half an hour of turning out to the fire, all 18 men were in the infirmary or killed.

Explosions, large and small occurred at frequent intervals, each scattering blazing debris in all directions, and gradually the whole works were destroyed. At the adjoining North Bierley Works in Cleckheaton Road, a large gasometer containing 270,000 cubic feet (7,600 m³) of gas was ruptured by falling debris. The escaping gas quickly ignited and the heat could be felt almost a mile away. In the nearby railway sidings almost 30 carriages and wagons were destroyed and 100 seriously damaged. Damage to surrounding areas was extensive, with broken windows in all houses and shops for 2 miles (3.2 km) around. Roofs were badly damaged, ceilings brought down and doors were broken, so that for several days, people could not live in their houses and were forced to camp out in neighbouring fields or live with relatives. Some properties were completely demolished by the blast and 29 houses in First Street were erected in 1919 to replace these. One thing which one eye witness recalls was the number of dogs running away in all directions, later to be found as far away as Wakefield, Huddersfield and Halifax. The official casualty figures given were – 34 people killed and 60 injured. These figures applied only to the works, but outside the works, many more were injured by flying glass and debris.[1]

On Tuesday 21 July 1992 a series of explosions leading to an intense fire broke out in a storeroom in a raw materials warehouse at Allied Colloids site in Low Moor, Bradford. The fire spread rapidly to the remainder of the warehouse and external chemical drum storage. Although none of the company employees were injured, 33 people, including three residents and 30 fire and/or police officers were taken to hospital where they were treated for smoke inhalation. Approximately 2000 local residents were confined to their houses and residents in eight properties immediately adjacent to the raw materials warehouse were evacuated.

The incident was first noted by a fork lift truck driver at 13:30 hours who saw a fume coming from a vent in what was termed an 'oxystore'. He set off the fire alarm which alerted the works fire brigade.

They, along with five senior managers and the safety manager, investigated and found that a number of kegs of azodiisobutyronitrile (AZDN), which is a reducing agent and which had been stored on an upper shelf, had ruptured and spilled their contents on the floor and had created a dust cloud. There was also a portion of a ceiling insulation tile on the ground. Part of it, which remained in situ, bore the marks of impact from a keg lid.

In the immediate vicinity of the spilled AZDN there were bags of sodium persulphate (SPS), an oxidising agent.

The internal fire crew brought up an appliance and laid out their hoses, but it was decided to clear up the spillage by means of a vacuum cleaner.

At 14:15 hours the shift chemist could see that a reaction was taking place in or near a bag of SPS. A flame developed, followed by a flash and he was forced to retreat. There was a further explosion (probably a dust explosion) which blew him over. By this time people were running away from the scene.

The public fire brigade were called at 14:22 hours and began arriving at 14:28 hours. There was thus a lapse of time of some 52 minutes between the first discovery, which resulted in the internal fire alarm being sounded, and the public fire brigade being summoned.

The brigade found that it was facing an intense fire. At its peak it required 36 appliances and 173 fire-fighters to combat it. The mains water supply proved inadequate and water had to be pumped from adjacent dams.[2]

The fire spread throughout the warehouse and smoke was blown towards nearby motorways. The fire was contained that day and the fire brigade was not stood down until 18 days later due to risk of re-ignition during clean up. Considerable environmental damage to the Aire and Calder rivers resulted from the firewater run off. Allied Colloids were convicted under the Health and Safety at Work Act 1974, Section 2 (two counts) and Section 3. The fire caused considerable local anxiety. In view of this the Health and Safety Executive published its investigation report.[3]

The investigation established that the fire had been initiated by the thermal decomposition of kegs of the thermally unstable reducing agent, AZDN in oxystore 2. This had arisen because of the proximity of the kegs to a hot steam condensate return line. There was a total of 1.9 tonnes of AZDN in oxystore 2. The powder released reacted with sodium persulphate, an oxidising agent, which was stored adjacent to it. It was also capable of burning in air.

An immediate underlying cause was that AZDN, a reducing agent, which was a chemical in regular use by AC had, for store-keeping purposes, been wrongly classified, in 1989, as an oxidising agent. This was why it was stored in an 'oxystore'.

Management of warehousing was another factor. Originally each production department had its own warehousing arrangements but this seems to have led to difficulties. To overcome these difficulties the Company had set up a 'Logistics' department in 1990. Though its area of responsibilities is not made clear in the HSE Report, it seems reasonable to assume that the chief responsibilities of the department were (1) receiving and storing raw materials, (2) storing, packaging and dispatching finished materials, (3) transporting raw materials from store to the point of production and (4) for taking finished chemicals from the point of production into store. It seems also to have had the responsibility for transporting and storing some intermediate products. The magnitude of these operations was disclosed by the 125 people employed in the department. However none of those employed in the Logistics department was qualified in chemistry. This was no doubt the reason why the errors in the classification of AZDN was not noticed. Nor was anyone in the Logistics department qualified in safety.

AZDN kegs were stored in the same section of the warehouse as SPS and other oxidising substances, after being wrongly classified in the documentation. Segregation of Hazardous Materials[1]: Warehouse storage, Incompatible substances Raw Materials Control / Sampling[2]: Safety management systems Failure of the steam heating system or operator error meant that heating was applied in No. 2 oxystore as well as in the main warehouse. Plant Modification / Change Procedures[3]: Decommissioning procedures The oxystores and warehouse were not fitted with adequate smoke detection and fire fighting facilities. Active / Passive Fire Protection[4] The fire brigade and police should have been informed immediately the first incident had been discovered. As it was there was a 50-minute delay before the fire occurred and the emergency services informed. Emergency Response / Spill control[5]: Site emergency plan, Stabilising to safe condition, fire fighting Significant environmental damage was caused to the Aire and Calder rivers by the fire-water run-off. Emergency Response / Spill Control[6]: Fire fighting Secondary Containment[7]: bunds, catchpots, barriers.