According to statistics from the Department for Communities & Local Government, out of 727,000 attendances to premises by fire and rescue services in 2008, 399,200 were due to false or unwanted alarms.
Hochiki Europe says: “Four years later, fire crews are still being needlessly called out when alarms are activated due to things such as burning toast. A large proportion of these false alarms came from hospital premises, which is partially understandable, due to their size and complexity. However, there is significant scope for improvement.”
Hochiki says fire and rescue services are now requesting that occupiers check there is a genuine blaze before dialling ‘999’, and, although this is reducing the number of unnecessary call-outs, local government bodies, and for example, NHS Trusts, are being urged to explore other ways to further reduce the burden imposed on emergency services. Suggestions include serving those that routinely raise false alarms with an improvement notice which could result in court action.
“The most common causes of unwanted alarms are poor product selection, misguided installation, the activities of people or processes within the building, and /or little or no system maintenance,” Hochiki explains. “To help eliminate the first of these it is advisable to carry out a risk assessment to identify likely fire risks, and then match the right products to the premises’ specific requirements. Careful consideration should then be given to their selection and siting.” For example, Hochiki says, manual call points should not be positioned where malicious damage can occur, and with automatic smoke detectors (the company maintains) ‘generating more unwanted alarms than any other type of detector’, they must be located in the most suitable area possible. Equally, when an area changes its use, the type of fire detector sited there should be reviewed.
Hochiki explains: “Some manufacturers build in features to their products to reduce unwanted alarms. For instance, optical chamber technology has been developed that minimises the differences in sensitivity experienced in flaming and smouldering fires, resulting in a chamber that is equally responsive to all smoke types.
“Products are also available that have a compensation feature against dust or dirt build- up. They automatically adjust the alarm threshold to account for any contamination within the sensor chamber, resulting in increased longevity and robustness. However, even with drift compensation algorithms employed, the physical removal of dust will eventually become necessary, and a good maintenance regime will ensure this happens at the appropriate time.”
With some detector designs, Hochiki explains, it is possible to simply and quickly dismantle the detector, remove the chamber, and clean or replace it on site. The company adds: “It is important to note that this should only be done where the manufacturer can guarantee that, once the detector has been reassembled, it will automatically recalibrate itself. Calibration in this way ensures that the sensitivity of the sensor is the same from the day it was installed until the contamination is beyond compensation, at which point it should be serviced again.
“There is clearly a strong link between the quality of fire detection equipment, system design and maintenance, and the reduction of unwanted alarms,” Hochiki concludes. “If the issue isn’t addressed, and with public sector budgets being reduced, it may well fall upon building owners to contribute to the cost of dealing with the problem.
Additional guidance on cutting the number of false alarms within premises is also available from a dedicated website recently created by the Fire Industry Association, here.
