Racking, Cardboard and Charge Points: Rethinking Fire Risk in the Modern Warehouse

Walk into a typical UK distribution warehouse and you are looking at one of the most concentrated fuel loads in British commerce. Thousands of square metres of polypropylene racking, aisles stacked floor to ceiling with corrugated cardboard, and — increasingly — banks of lithium-ion batteries powering the forklifts and pallet trucks that keep the whole operation moving. Fire safety in this environment is not a scaled-up version of office compliance. It is a distinct discipline, and treating it as anything less is where serious premises come unstuck.

The Vertical Fuel Problem

The defining feature of warehouse fire risk is height. High-bay racking transforms a routine sprinkler design into a complex engineering question, because fire does not stay at floor level. A fire starting at the base of a rack can climb through packaging faster than suppression can reach it, and the racking itself — particularly older installations — can shield burning material from overhead sprinklers entirely.

A competent fire risk assessment should therefore interrogate:

• Sprinkler coverage versus storage height. Where racking has been reconfigured or extended since the original sprinkler design, in-rack sprinklers or a revised design density may be required. This is one of the most common — and most consequential — findings we encounter.
• Storage discipline. Cartons stacked above sprinkler heads, pallets leaning into clearance zones, and goods stored against fire-rated walls all erode the assumptions behind the building's fire strategy.
• Flue spaces. The longitudinal and transverse flues between racking and stock are not wasted space. They are engineered pathways that allow sprinkler water and smoke ventilation to function. Block them with overhanging stock and suppression performance degrades sharply.

Cardboard, Dust and the Autumn Build-Up

Corrugated board is the workhorse of UK logistics and its most abundant fuel. Loose packaging waste, broken-down boxes awaiting baling, and shrink-wrap offcuts accumulate in exactly the corners that cleaning schedules miss. Add cardboard dust settling on light fittings, electrical distribution boards and heater housings, and you have a ready-made ignition chain.

This risk sharpens seasonally. From late autumn through the peak trading period, warehouses operate at maximum storage density, temporary racking appears on gangways, and waste accumulates faster than housekeeping can manage. The winter months also bring portable heating into packing areas and increased electrical loading — a combination that deserves explicit attention in any seasonal review. A fire risk assessment conducted in a quiet February may not reflect the premises as they stand in the second week of December.

Lithium-Ion Charging Zones: The New Frontier

Battery-powered materials handling equipment has shifted the risk profile of the modern warehouse significantly. Lithium-ion batteries fail in ways lead-acid never did: thermal runaway can be sudden, self-sustaining and intensely difficult to extinguish with conventional means.

A thorough assessment should examine where and how charging takes place. Key red flags include charging points located against racking or stock, batteries charged overnight in unmonitored areas, damaged or third-party replacement batteries in circulation, and a absence of dedicated fire separation around charging bays. Best practice places charging zones in a segregated, well-ventilated area away from storage and escape routes, with charging scheduled where possible during staffed hours and smoke detection specific to the bay.

Insurers are watching this closely. Several UK underwriters now scrutinise lithium battery arrangements as a distinct underwriting question, and an inadequate charging setup can affect both premium and cover.

Aisles, Escape and the Human Element

Fire safety in warehouses also lives or dies on layout discipline. Marked gangways that double as overflow storage, pedestrian routes that narrow during peak season, and fire exit routes blocked by palletised stock are all findings that appear with depressing regularity. Emergency escape routes must be treated as fixed infrastructure, not flexible capacity, however great the seasonal pressure.

Equally important is staff familiarity. High turnover in logistics means that induction training, refresher drills and clear marshalling arrangements matter more here than in most sectors. A fire strategy that exists only in a document in the site office protects no one.

What a Competent Assessment Should Deliver

For warehousing and logistics premises, a meaningful fire risk assessment should conclude with site-specific, prioritised actions: verification that suppression design matches current storage arrangements, a documented housekeeping and waste regime, a dedicated review of battery charging infrastructure, and confirmation that escape routes and flue spaces are protected from operational creep.

Warehouses will always be buildings full of fuel. The difference between a managed risk and an accumulating one lies in whether the assessment reflects the premises as they actually operate — at peak, in winter, with the chargers running and the racking full. If your last assessment was a desktop exercise that didn't walk the aisles, it is time to look again.