Smoke Alarms be Replaced After 10 years.
In 1992, the Building Regulations were amended
requiring every new build to allow for mains-wired, interconnected smoke
alarms to be installed. With many alarms installed under this Regulation
still in use and potentially approaching their twentieth year, it was necessary
to research a recommendation as to when mains powered smoke alarms should be
replaced.
Current
recommendations
1.
The majority of
research found on this subject emanates from the US. The US National Fire
Protection Association (NFPA) have issued NFPA Standard 72, National Fire Alarm
and Signalling Code (2010 edition), which states:
1.
"Replace all
smoke alarms, including those that use ten-year batteries and hard-wired
alarms, when they are ten years old or sooner if they don’t respond properly
when tested."
2.
US fire safety
websites, along with those in the UK, Canada, New Zealand and Australia, tend
to recommend the replacement of domestic smoke alarms, whether battery or
mains-wired, when they:
o
Fail to respond to
tests
o
Are ten years old
(varying between date of installation and manufacture)
Why Replace Alarms?
Several reasons are provided to justify the
replacement of smoke alarms after ten years.
3.
The Minnesota
Department of Public Safety cite a nationwide study undertaken by the Consumer
Product Safety Commission (CPSC), which states that 97% of smoke alarms should
still be functioning after one year, if supplied with power. After ten years it
is 73%, whereas after 20 years, this figure stands at 54%. The study also
indicated that 60% of the failures were due to flat or removed batteries or a
disconnected power supply and the study offered possible reasons for this.
Ageing alarms may experience sensitivity drifting, which may, in turn, result in
an increased frequency of accidental activation and an increase in people
removing the power supply. It was thought that newer alarms with a ‘hush’
feature may contribute to remedying this
4.
An NFPA report cites a
study undertaken by Canada’s Ontario Housing Corporation supporting the fact
that 3% of smoke alarms will fail within one year. They also say that after 30
years, nearly all the alarms will have failed. They conclude that replacement
after ten years, with roughly a 30% probability of failure, is an appropriate
balance between safety and cost
5.
The South Australian
Metropolitan Fire Service state that smoke alarm technology has improved
significantly since legislation was introduced (similar requirements to the
1992 UK ones were introduced in Australia in 1995) and replacing old smoke
alarms is an ideal opportunity to upgrade smoke alarm systems. The Australian
Standard for smoke alarms (AS 3786) specifies an effective life of 10 years,
suggesting that after that time effectiveness may be compromised with
accumulated dust, insects, airborne contaminants and corrosion of electrical
circuitry
6.
In the early 1990s,
the US Consumer Product Safety Commission undertook an extensive study, called
the National Smoke Detector Project, to examine smoke alarm ownership and
operability. Some failures were found in smoke alarms, but there were no large
or systematic problems identified with detector designs or manufacturing
practices that cast any doubt on their long term reliability. However, a
variety of component failures, corroded battery clips and deterioration and
corrosion of the horn element contacts were found in a few smoke alarms
7.
Other reports from New
Zealand and Canada looked at operability of battery smoke alarms, but no
further reports on the operability and longevity of mains-wired smoke alarms
could be found
Testing Smoke Alarms
8.
It should be noted
that the regular testing of smoke alarms should help identify
inoperability as testing a smoke alarm simulates smoke and does not simply test
the power supply. This would indicate smoke alarm maintenance messages remain a
priority. However, it was queried whether all smoke alarm test functions
operate in this way, or whether some simply do test power supply, be it battery
or mains-wired
9.
The general view from
UK based smoke alarm manufacturers reflects the findings elsewhere. With
contaminants such as dust, insects, grease and nicotine, the smoke alarm
chamber is susceptible to becoming excessively sensitive or insensitive. This
may lead to either an increase in nuisance false alarms, or to eventually
becoming unable to detect smoke. One manufacturer reports that contamination is
extremely variable, but that field experience indicated that 10 years is a
reasonable compromise
Conclusion
10. Evidence of smoke alarm longevity appears to
be scarce and inconclusive. As with other electronic items, there will be
failures in the units when they are produced and failures during their lifetime
due to individual component faults. Similarly, as they get older more faults
are likely to occur. Problems specific to smoke detectors include increased
sensitivity
11. In all the work identified so far, none has
specifically concentrated on the failure of smoke alarms when they age. Smoke
alarms do fail but the rate at which they do has not been accurately determined
or related to their age.
12. Despite there not being much research, it does
seem appropriate to replace smoke alarms after ten years (in line with
manufacturers advice), unless individual alarm testing suggests earlier replacement.
Mains-wired
interconnected alarms – Replacement kits
13. Safelincs has developed products designed to
help facilitate the process of replacing the smoke detector heads for
mains-wired interconnected smoke alarms
Disposal of old Smoke
Alarms
Smoke and heat alarms fall under the WEEE (Waste Electrical and
Electronic Equipment) regulations. Under the regulations retailers pay a fee to
allow their customers to take old smoke and heat alarm to their local recycling
centre (Distributor Take-Back Scheme). To find you local recycling centre visit
the recycle-more bank
locator.
Domestic Customers
Ideally old smoke and heat alarms should be taken to local
recycling centres for disposal. However small numbers of alarms can be disposed
of along with normal household refuse, a common misunderstanding is that the
crossed-out wheelie bin on the back of the alarm means that they must not be
placed in a normal waste bin. This symbol actually just means that the alarm
falls under the WEEE regulations.
Business Customers
Business customers cannot dispose of smoke alarms along with
their normal refuse and should instead take them to their local recycling
centre.
Customer Purchasing from Safelincs
Customers that purchased their alarms from Safelincs originally
or that are purchasing new alarms from us now can send their old alarms back to
us for disposal.