High-bay warehouse: sprinkler impairment with aerosol storage
A 12,000 m² single-storey distribution warehouse stores 600 pallets of aerosol deodorants and 200 pallets of water-based paint in racking up to 8 m high. The building has a sprinkler system designed to an older specification, smoke ventilation, and a BS 5839-1 L1 alarm. On a Friday afternoon, a sprinkler control valve is found closed after a repair; the contractor says the system will be out of service until Monday. The warehouse operates 24/7 with 35 staff per shift. There are two 100 mm fire hydrants on site but the nearest fire station is 12 minutes away. A hot-work permit was issued yesterday for racking repair, but the permit has no fire watch recorded after work. Housekeeping is poor: cardboard packaging is stored against an electrical distribution board, and a forklift battery charging area has no ventilation. The site fire plan is three years old and does not include the new high-bay racking.
1. Assess whether the warehouse should continue operating while the sprinkler system is isolated. Justify your decision and state the interim measures you would require.
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The decision should not be a simple 'continue' or 'stop'. The sprinkler system is the principal suppression for a high-challenge fire involving aerosols and high-bay racking, and it will be unavailable for up to three days. The fire service response of about 12 minutes is unlikely to prevent a large fire in 8 m racking. Continuing normal operations would leave a significant residual risk.
My judgement: the site should not continue full operations unless robust compensatory measures are in place and the insurer and fire and rescue service have been consulted. At minimum:
- implement a written impairment procedure and notify the insurer and FRS;
- stop receipt of further aerosol stock and reduce aerosol pallets in the affected area;
- prohibit all hot work and other ignition sources;
- provide a trained fire watch with patrols at defined intervals, backed by a written log, for the whole impairment period;
- confirm the alarm, smoke ventilation and hydrants are operational;
- clear combustibles from around electrical equipment and the charging area;
- brief all shift staff and brief the fire service on arrival.
If those measures cannot be resourced, or if the sprinkler cannot be restored by Monday, I would recommend shutting down storage of aerosols and restricting the warehouse to low-hazard goods. A fire watch is a warning/response measure, not a substitute for suppression, so it should be time-limited and reviewed daily.
2. Identify the fire prevention and protection deficiencies and recommend improvements.
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Deficiencies and improvements:
- Hot-work permit without a fire watch record. The permit is incomplete. Require a signed permit with area preparation, removal of combustibles, fire watch during work and for at least the specified post-work period, and a final check. The contractor should be inducted and supervised.
- Cardboard against an electrical distribution board. This combines fuel with an ignition source. Remove waste, provide designated waste storage away from the building/electrical equipment, and include housekeeping in daily checks.
- Forklift battery charging without ventilation. Charging can produce hydrogen; provide a ventilated, fire-resisting charging area, control ignition sources, and train staff.
- Sprinkler impairment. As above: impairment procedure, compensatory fire watch, insurer/FRS notification, urgent restoration.
- Out-of-date fire plan. It must include the high-bay racking, aerosol storage, evacuation routes, assembly points, isolation points and contact details; staff need training and drills.
- Protection design. The 8 m racking and aerosol storage may exceed the original sprinkler design; a fire engineer should verify coverage, in-rack sprinklers and smoke ventilation.
The prevention priority is to remove ignition sources and keep combustibles away from electrical equipment; the protection priority is to restore sprinklers and maintain detection/ventilation.