By Eamonn Ryan
How Hypoxic Fire Prevention is improving cold store safety.
In a cold store – where temperatures plunge to -20°C and racks stretch high with perishable goods – fire is likely the last thing on anyone’s mind. Yet, the threat is real, and insurance companies are taking notice. Traditional fire suppression systems – particularly in freezer environments – can be inadequate and problematic.
“Insurance companies are increasingly rejecting coverage due to inadequate fire suppression, especially in high-risk freezer environments,” says Andrew Brink, CEO of Gas At Site.
Hypoxic fire prevention is a solution that doesn’t wait for flames to flare but stops them from igniting in the first place. “This proactive approach, led by systems like Isolcell N2ORS, prevents fire before ignition – flipping the traditional model on its head.”
Brink explains the core concept: “A fire needs oxygen. If you reduce the oxygen level in a protected space to 15%, a fire simply can’t start. Traditional fire suppression systems only activate once a fire is already burning – using water, foam or inert gases to extinguish the flames. But for cold stores, especially those filled with high-value perishables, this approach is flawed.
“The hypoxic (low oxygen) system continuously floods the storage area with nitrogen – harmless, inert and abundant – to reduce the oxygen level just below the combustion threshold. Unlike suppression, there’s no waiting, no response delay, and – most importantly – no water damage,” Brink adds.
“Water is the last thing you want in a -20°C environment. If those sprinkler heads go off accidentally, you’re left with an ice rink and a warehouse that’s out of commission for months. We’ve seen it happen.”
Built for the cold chain
So why are cold storage facilities especially suited for this technology? Brink points to the structural materials used. “Insulation panels don’t have the same fire rating as bricks and mortar. If a fire does start, it can spread more aggressively in a cold store. Combine that with densely packed racking systems, which obstruct water nozzles, and you get the perfect conditions for uninsurable risk.”
This is a growing issue, particularly in South Africa. “Some facilities are now deemed uninsurable, not because fires are frequent, but because suppression systems can’t guarantee coverage in hard- to-reach corners.”
With hypoxic fire prevention systems, that concern is nullified. The low-oxygen atmosphere fills every void, crevice and recess in the facility, ensuring universal coverage. “Unlike water or foam, nitrogen permeates everything. It doesn’t care about shadows or shelving. Fire can’t start – anywhere.”
One might worry about safety in a room with just 15% oxygen. But according to Brink, there’s no risk. “Humans can work safely in that environment for up to eight hours, with short breaks in between. You’d barely notice unless you started running laps.”
Gas At Site’s legacy lies in controlled- atmosphere storage for fruit – particularly apples and pears – where oxygen is reduced to below 1% to extend shelf life. Apples go to sleep and can be stored for up to a year without spoilage. “This heritage in precision-atmosphere control is what powers N2ORS’s reliability.”
For cold stores housing produce, this synergy is ideal. The same nitrogen- generation technology keeps fruit fresh and fire-free. And for other perishable items, like frozen meats stored in cardboard, hypoxic conditions don’t pose any risk to product integrity.
Smart monitoring, real time
The backbone of the Isolcell N2ORS system is its sophisticated oxygen monitoring technology. “We deploy a lattice of sensors, each with triple redundancy,” says Brink. “They measure oxygen – not nitrogen – and send real-time data to a central control system.” If oxygen levels begin to rise due to a door opening or unexpected leakage, the system injects more nitrogen to maintain the safe threshold. This closed-loop feedback runs 24/7, with alerts, fail safes and alarms to ensure both safety and continuity.
Automated warehouses are particularly well-suited. With fewer doors and smaller access points – like conveyor apertures – they minimise nitrogen loss and maximise energy efficiency. “Less leakage means less electricity spent on nitrogen generation,” Brink explains. There’s also a constraint as to how effective water fire suppression is in automated racking if a fire starts under a rack.
Insurers stamp of approval
Perhaps the most compelling endorsement of the system comes from the insurance industry. “Insurers love it,” says Brink. “They recognise that the risk is eliminated at source. There’s no fire, so there’s no claim.”
This shift is significant in an era where risk tolerance is shrinking, and premiums are rising. For facility operators struggling to meet ever-stricter insurance requirements – particularly those with complex racking or limited space for traditional fire suppression infrastructure – hypoxic systems offer a viable, modern alternative.
Cost considerations and ROI
Depending on the application, the upfront investment can be equal to or slightly higher than the cost of a traditional sprinkler system, but Brink argues the long-term value is undeniable. There’s no need for massive water tanks, no risk of product loss from accidental discharge, and no downtime from post-fire cleanup.
“There’s an energy component, since nitrogen must be generated continually. But the operational cost is outweighed by the protection, efficiency and peace of mind.”
Developed by Isolcell, an Italian company with roots in controlled- atmosphere storage since 1958, the hypoxic fire prevention solution has been installed over 150 times across Europe.
And for South Africa, the technology has already made inroads in both fruit storage and broader cold chain facilities. It keeps products safe, operations uninterrupted and insurers satisfied – all while eliminating the threat before it sparks.
As Brink puts it: “It’s not fire suppression. It’s fire prevention. That makes all the difference.”