It sounds like the plot of a soap opera… a worker is trapped inside a supermarket refrigerator and nobody knows she is there until a body is found the next day.
This was indeed a storyline on Coronation Street back in the 1990s and while health and safety regulations have become more stringent since then, the dangers still exist when staff are working in cold stores and refrigerated warehouses.
Regular risk assessments will identify potential dangers and help employers identify what precautions should be introduced.
In addition, safe ways of working should be developed and put into practice.
There is, however, an extremely simple and cost-effective device which can safeguard staff welfare and help operators comply with health and safety legislation.
A trapped personnel alarm, such as the one manufactured by Stonegate Instruments, is an inexpensive and straightforward to install device which prevents employees becoming trapped inside a cold store.
If someone becomes trapped, they hit an emergency alarm button inside the store which triggers audio and visual alarms, with the monitors backed up by batteries in case of a mains failure. The display also sets a volt-free relay to repeat the call to a siren or other remote alarm.
The alarm itself is compact – just 122mm x 122m x 65mm in height, width and depth – with 5mm pitch screw terminals and a maximum cable size of 2.5mm.
Another consideration for operators of commercial refrigeration equipment is the prevention of gas leaks. While gases are essential to the refrigeration process, leaks can be harmful both to staff and the environment as well as affecting the equipment’s performance.
Workers need to be aware of the dangers of working with refrigerants, particularly since around 60% of gas escapes before anyone notices.
Current legislation demands that refrigeration systems with 300kg or more of refrigerants must be fitted with a leak detector. Those with a charge of 30kg or more must be tested for leaks twice annually and systems with a charge of between 3-30kg are required to be tested once a year.
The gas detectors themselves need to have a sensitivity of 5g per year and be calibrated with a 1,000ppm mix of gas to air. They should be checked after 25 hours’ continuous use.
Devices such as Stonegate Instruments’ DL 1024 fulfil all these requirements and operate 24-7, detecting a range of both toxic and non-toxic gases, including hydrofluorocarbons, or HFCs, which are known to have a high global warming potential.
LED colours indicate the status of each sensor, meaning that if any gas leak is sensed, not only are audio and visual alarms activated, staff members can immediately identify exactly what and where the problem is, so that it can be swiftly rectified.
The audio alarm can be muted but will remain on a relay until all sensors in the affected zone have been cleared.
Gas leaks also have a detrimental effect on equipment performance. Research shows a typical 300kW refrigeration system with a small, continuous leak left unrepaired for three months could result in an extra 10kW of electricity being used. In financial terms, this means an energy bill increase of around £1,400 – not to mention the cost of repairs, which are likely to be higher the longer the leak is left.
Doors accidentally left open are another contributor to increased energy bills. This simple error can prove costly, as not only must the system must work harder to maintain temperature levels, it can result in the refrigerated goods being spoiled.
One simple prevention measure is to fit an open door alarm which alerts the workforce should a door be accidentally left open for any length of time. Stonegate Instruments’ Door Open Alarm uses a flashing xenon beacon and two audio alarms to draw attention to a cold-room door being left open.
Often it is the simplest solutions which can address the most complex problems. Shaun Evers, managing director of Stonegate Instruments, said: “While there may be stringent regulations surrounding the use of refrigerated equipment, often there can be a straightforward and all-encompassing solution available. A trapped personnel alarm could save a life while an open-door alert could prevent valuable goods and expensive energy going to waste.”
Stonegate Instruments designs, develops and manufactures electronic equipment for the refrigeration industry. The company’s products are proven in cold storage facilities for reducing energy, carbon emissions and the associated costs.