Smoke detector | Wikipedia audio article

Smoke detector | Wikipedia audio article


A smoke detector is a device that senses smoke,
typically as an indicator of fire. Commercial security devices issue a signal
to a fire alarm control panel as part of a fire alarm system, while household smoke detectors,
also known as smoke alarms, generally issue a local audible or visual alarm from the detector
itself. Smoke detectors are housed in plastic enclosures,
typically shaped like a disk about 150 millimetres (6 in) in diameter and 25 millimetres (1 in)
thick, but shape and size vary. Smoke can be detected either optically (photoelectric)
or by physical process (ionization); detectors may use either, or both, methods. Sensitive alarms can be used to detect, and
thus deter, smoking in areas where it is banned. Smoke detectors in large commercial, industrial,
and residential buildings are usually powered by a central fire alarm system, which is powered
by the building power with a battery backup. Domestic smoke detectors range from individual
battery-powered units, to several interlinked mains-powered units with battery backup; with
these interlinked units, if any unit detects smoke, all trigger even if household power
has gone out. The risk of dying in a home fire is cut in
half in homes with working smoke alarms. The US National Fire Protection Association
reports 0.53 deaths per 100 fires in homes with working smoke alarms compared to 1.18
deaths in homes without (2009–2013). Some homes do not have any smoke alarms, some
alarms do not have working batteries; sometimes the alarm fails to detect the fire.==History==
The first automatic electric fire alarm was patented in 1890 by Francis Robbins Upton,
an associate of Thomas Edison. George Andrew Darby patented the first European
electrical heat detector in 1902 in Birmingham, England. In the late 1930s Swiss physicist Walter Jaeger
tried to invent a sensor for poison gas. He expected that gas entering the sensor would
bind to ionized air molecules and thereby alter an electric current in a circuit in
the instrument. His device did not meet its purpose: small
concentrations of gas had no effect on the sensor’s conductivity. Frustrated, Jaeger lit a cigarette and was
soon surprised to notice that a meter on the instrument had registered a drop in current. Smoke particles from his cigarette had apparently
done what poison gas could not. Jaeger’s experiment was one of the advances
that paved the way for the modern smoke detector. In 1939 Swiss physicist Ernst Meili devised
an ionization chamber device capable of detecting combustible gases in mines. He also invented a cold cathode tube that
could amplify the small signal generated by the detection mechanism to a strength sufficient
to activate an alarm.Ionization smoke detectors were first sold in the United States in 1951;
they were used only in major commercial and industrial facilities in the next several
years due to their large size and cost. In 1955 simple home “fire detectors” for homes
were developed, detecting high temperatures. The United States Atomic Energy Commission
(USAEC) granted the first license to distribute smoke detectors using radioactive material
in 1963. The first low-cost smoke detector for domestic
use was developed by Duane D. Pearsall in 1965, an individual replaceable battery-powered
unit that could be easily installed. The “SmokeGard 700” was a beehive-shaped,
strong fire-resistant steel unit. The company began mass-producing these units
in 1975. Studies in the 1960s determined that smoke
detectors respond to fires much faster than heat detectors.The first single-station smoke
detector was invented in 1970 and made public the next year. It was an ionization detector powered by a
single 9-volt battery. They cost about US$125 and sold at a rate
of a few hundred thousand per year. Several technological developments occurred
between 1971 and 1976, including the replacement of cold-cathode tubes with solid-state electronics,
which greatly reduced the detectors’ cost, sizes and made it possible to monitor battery
life. The previous alarm horns, which required specialty
batteries, were replaced with horns that were more energy-efficient, enabling the use of
commonly available batteries. These detectors could also function with smaller
amounts of radioactive source material, and the sensing chamber and smoke detector enclosure
were redesigned for more effective operation. The rechargeable batteries were often replaced
by a pair of AA batteries along with a plastic shell encasing the detector. The 10-year-lithium-battery-powered smoke
alarm was introduced in 1995.The photoelectric (optical) smoke detector was invented by Donald
Steele and Robert Emmark of Electro Signal Lab and patented in 1972.==Design=====
Ionization===An ionization smoke detector uses a radioisotope,
typically americium-241, to ionize air; a difference due to smoke is detected and an
alarm is generated. Ionization detectors are more sensitive to
the flaming stage of fires than optical detectors, while optical detectors are more sensitive
to fires in the early smouldering stage.The smoke detector has two ionization chambers,
one open to the air, and a reference chamber which does not allow the entry of particles. The radioactive source emits alpha particles
into both chambers, which ionizes some air molecules. There is a potential difference (voltage)
between pairs of electrodes in the chambers; the electrical charge on the ions allows an
electric current to flow. The currents in both chambers should be the
same as they are equally affected by air pressure, temperature, and the ageing of the source. If any smoke particles enter the open chamber,
some of the ions will attach to the particles and not be available to carry the current
in that chamber. An electronic circuit detects that a current
difference has developed between the open and sealed chambers, and sounds the alarm. The circuitry also monitors the battery used
to supply or back up power, and sounds an intermittent warning when it nears exhaustion. A user-operated test button simulates an imbalance
between the ionization chambers, and sounds the alarm if and only if power supply, electronics,
and alarm device are functional. The current drawn by an ionization smoke detector
is low enough for a small battery used as sole or backup power supply to be able to
provide power for months or years without the need for external wiring. Ionization smoke detectors are usually cheaper
to manufacture than optical detectors. They may be more prone to false alarms triggered
by non-hazardous events than photoelectric detectors, and have been found to be much
slower to respond to typical house fires. Americium-241 is an alpha emitter with a half-life
of 432.6 years. Alpha particle radiation, as opposed to beta
(electron) and gamma (electromagnetic) radiation, is used for two additional reasons: alpha
particles have high ionization, so sufficient air particles will be ionized for the current
to exist, and they have low penetrative power, meaning they will be stopped, safely, by the
plastic of the smoke detector or the air. About one percent of the emitted radioactive
energy of 241Am is gamma radiation. The amount of elemental americium-241 is small
enough to be exempt from the regulations applied to larger sources. It includes about 37 kBq or 1 µCi of radioactive
element americium-241 (241Am), corresponding to about 0.3 µg of the isotope. This provides sufficient ion current to detect
smoke, while producing a very low level of radiation outside the device. The americium-241 in ionizing smoke detectors
poses a potential environmental hazard, albeit a very small one. Disposal regulations and recommendations for
smoke detectors vary from region to region. The amount of radioactive material contained
in ionizing smoke detectors is very small and thus doesn’t represent a significant radiological
hazard. If the americium is left in the ionization
chamber of the alarm the radiological risk is insignificant because the chamber acts
as a shield to the alpha radiation. A person would have to open the sealed chamber
and ingest or inhale the americium for the risk to be significant. The radiation risk of exposure to an ionic
smoke detector operating normally is much smaller than natural background radiation. Some European countries, including France,
and some US states and municipalities have banned the use of domestic ionic smoke alarms
because of concerns that they are not reliable enough as compared to other technologies. Where an ionizing smoke detector has been
the only detector, fires in the early stages have not always been effectively detected.===Photoelectric===A photoelectric, or optical smoke detector
contains a source of infrared, visible, or ultraviolet light (typically an incandescent
light bulb or light-emitting diode), a lens, and a photoelectric receiver (typically a
photodiode). In spot-type detectors all of these components
are arranged inside a chamber where air, which may contain smoke from a nearby fire, flows. In large open areas such as atria and auditoriums,
optical beam or projected-beam smoke detectors are used instead of a chamber within the unit:
a wall-mounted unit emits a beam of infrared or ultraviolet light which is either received
and processed by a separate device, or reflected back to the receiver by a reflector. In some types, particularly optical beam types,
the light emitted by the light source passes through the air being tested and reaches the
photosensor. The received light intensity will be reduced
due to scattering from particulates of smoke, air-borne dust, or other substances; the circuitry
detects the light intensity and generates the alarm if it is below a specified threshold,
potentially due to smoke. In other types, typically chamber types, the
light is not directed at the sensor, which is not illuminated in the absence of particles. If the air in the chamber contains particles
(smoke or dust), the light is scattered and some of it reaches the sensor, triggering
the alarm.According to the National Fire Protection Association (NFPA), “photoelectric smoke detection
is generally more responsive to fires that begin with a long period of smoldering”. Studies by Texas A&M and the NFPA cited by
the City of Palo Alto, California state, “Photoelectric alarms react slower to rapidly growing fires
than ionization alarms, but laboratory and field tests have shown that photoelectric
smoke alarms provide adequate warning for all types of fires and have been shown to
be far less likely to be deactivated by occupants.” Although photoelectric alarms are highly effective
at detecting smoldering fires and do provide adequate protection from flaming fires, fire
safety experts and the National Fire Protection Agency recommend installing what are called
combination alarms, which are alarms that either detect both heat and smoke, or use
both the ionization and photoelectric processes. Some combination alarms may include a carbon
monoxide detection capability. The type and sensitivity of light source and
photoelectric sensor, and type of smoke chamber differ between manufacturers.===Carbon monoxide and carbon dioxide detection
===Carbon monoxide sensors detect potentially
fatal concentrations of carbon monoxide gas, which may build up due to faulty ventilation
where there are combustion appliances such as gas heaters and cookers, although there
is no uncontrolled fire outside the appliance.High levels of carbon dioxide (CO2) may indicate
a fire, and can be detected by a carbon dioxide sensor. Such sensors are often used to measure levels
of CO2 which may be undesirable but not indicative of a fire; this type of sensor can also be
used to detect and warn of the much higher levels generated by a fire. One manufacturer says that detectors based
on CO2 levels are the fastest fire indicators, and also, unlike ionization and optical detectors,
detect fires that do not generate smoke, such as those fuelled by alcohol or gasoline. CO2 fire detectors are not susceptible to
false alarms due to particles, making them particularly suitable for use in dusty and
dirty environments.===Performance differences===
A presentation by Siemens and the Canadian Fire Alarm Association reports the ionization
detector as best at detecting incipient-stage fires with invisibly small particles, fast-flaming
fires with smaller 0.01-0.4 micron particles, and dark or black smoke, while more modern
photoelectric detectors are best at detecting slow-smouldering fires with larger 0.4–10.0
micron particles, and light-coloured white/grey smoke.Photoelectric smoke detectors respond
faster to fire in its early, smouldering stage (before it breaks into flame). The smoke from the smouldering stage of a
fire is typically made up of large combustion particles—between 0.3 and 10.0 µm. Ionization smoke detectors respond faster
(typically 30–60 seconds) in the flaming stage of a fire. The smoke from the flaming stage of a fire
is typically made up of microscopic combustion particles—between 0.01 and 0.3 µm. Also, ionization detectors are weaker in high
air-flow environments, and because of this, the photoelectric smoke detector is more reliable
for detecting smoke in both the smoldering and flaming stages of a fire.In June 2006,
the Australasian Fire & Emergency Service Authorities Council, the peak representative
body for all Australian and New Zealand fire departments, published an official report,
‘Position on Smoke Alarms in Residential Accommodation’. Clause 3.0 states, “Ionization smoke alarms
may not operate in time to alert occupants early enough to escape from smouldering fires.”In
August 2008, the International Association of Fire Fighters (IAFF, with over 300,000
members in North America) passed a resolution recommending the use of photoelectric smoke
alarms, saying that changing to photoelectric alarms, “Will drastically reduce the loss
of life among citizens and fire fighters.”In May 2011, the Fire Protection Association
of Australia’s (FPAA) official position on smoke alarms stated, “Fire Prevention Association
Australia considers that all residential buildings should be fitted with photoelectric smoke
alarms…”In December 2011, the Volunteer Fire Fighter’s Association of Australia published
a World Fire Safety Foundation report, ‘Ionization Smoke Alarms are DEADLY’, citing research
outlining substantial performance differences between ionization and photoelectric technology.In
November 2013, the Ohio Fire Chiefs’ Association (OFCA) published an official position paper
supporting the use of photoelectric technology in Ohioan residences. The OFCA’s position states, “In the interest
of public safety and to protect the public from the deadly effects of smoke and fire,
the Ohio Fire Chiefs’ Association endorses the use of Photoelectric Smoke Alarms … In
both new construction and when replacing old smoke alarms or purchasing new alarms, we
recommend Photoelectric Smoke Alarms.”In June 2014, tests by the North Eastern Ohio Fire
Prevention Association (NEOFPA) on residential smoke alarms were broadcast on the ABC’s ‘Good
Morning America’ program. The NEOFPA tests showed ionization smoke alarms
failing to activate in the early, smoldering stage of fire. The combination ionization-photoelectric alarms
failed to activate until an average of over 20 minutes after the stand-alone photoelectric
smoke alarms. This vindicated the June 2006 official position
of the Australasian Fire & Emergency Service Authorities Council (AFAC) and the October
2008, official position of the International Association of Fire Fighters (IAFF). Both AFAC and the IAFF recommend photoelectric
smoke alarms, but not combination ionization/photoelectric smoke alarms.According to fire tests conformant
to EN 54, the CO2 cloud from open fire can usually be detected before particulate.Due
to the varying levels of detection capabilities between detector types, manufacturers have
designed multi-criteria devices which cross-reference the separate signals to both rule out false
alarms and improve response times to real fires.Obscuration is a unit of measurement
that has become the standard way of specifying smoke detector sensitivity. Obscuration is the effect that smoke has on
reducing light intensity, expressed in percent absorption per unit length; higher concentrations
of smoke result in higher obscuration levels.==Commercial==Commercial smoke detectors are either conventional
or addressable, and are connected to security alarm or fire alarm systems controlled by
fire alarm control panels (FACP). These are the most common type of detector,
and are usually significantly more expensive than single-station battery-operated residential
smoke alarms. They are used in most commercial and industrial
facilities and other places such as ships and trains, but are also part of some security
alarm systems in homes. These detectors don’t need to have built in
alarms, as alarm systems can be controlled by the connected FACP, which will set off
relevant alarms, and can also implement complex functions such as a staged evacuation.===Conventional===
The word “conventional” is slang used to distinguish the method used to communicate with the control
unit in newer addressable systems. So called “conventional detectors” are smoke
detectors used in older interconnected systems and resemble electrical switches by their
way of working. These detectors are connected in parallel
to the signaling path so that the current flow is monitored to indicate a closure of
the circuit path by any connected detector when smoke or other similar environmental
stimulus sufficiently influences any detector. The resulting increase in current flow (or
a dead short) is interpreted and processed by the control unit as a confirmation of the
presence of smoke and a fire alarm signal is generated. In a conventional system, smoke detectors
are typically wired together in each zone and a single fire alarm control panel usually
monitors a number of zones which can be arranged to correspond to different areas of a building. In the event of a fire, the control panel
is able to identify which zone or zones contain the detector or detectors in alarm, but can
not identify which individual detector or detectors are in a state of alarm.===Addressable===An addressable system gives each detector
an individual number, or address. Addressable systems allow the exact location
of an alarm to be plotted on the FACP, while allowing several detectors to be connected
to the same zone. In certain systems, a graphical representation
of the building is provided on the screen of the FACP which shows the locations of all
of the detectors in the building, while in others the address and location of the detector
or detectors in alarm are simply indicated.Addressable systems are usually more expensive than conventional
non-addressable systems, and offer extra options, including a custom level of sensitivity (sometimes
called Day/Night mode) which can determine the amount of smoke in a given area and contamination
detection from the FACP that allows determination of a wide range of faults in detection capabilities
of smoke detectors. Detectors become contaminated usually as a
result of the build up of atmospheric particulates in the detectors being circulated by the heating
and air-conditioning systems in buildings. Other causes include carpentry, sanding, painting,
and smoke in the event of a fire. Panels can also be interconnected to monitor
a very large number of detectors in multiple buildings. This is most commonly used in hospitals, universities,
resorts and other large centres or institutions.==Residential==
Smaller, less expensive, smoke alarm systems, typically used in a domestic/residential environment,
may be individual standalone units, or interconnected. They typically generate a loud acoustic warning
signal as their only action. Several detectors (whether standalone or interconnected)
are normally used in the rooms of a dwelling. There are inexpensive smoke alarms that may
be interconnected so that any detector that triggers sounds all alarms. They are powered by mains electricity, with
disposable or rechargeable battery backup. They may be interconnected by wires, or wirelessly.They
are required in new installations in some jurisdictions.Several smoke detection methods
are used and documented in industry specifications published by Underwriters Laboratories. Alerting methods include: Audible tones
Usually around 3200 Hz due to component constraints (Audio advancements for persons with hearing
impairments have been made) 85 dBA loudness at 10 feet
Spoken voice alert Visual strobe lights
177 candela output Tactile stimulation (e.g. bed or pillow shaker),
although no standards existed as of 2008 for tactile stimulation alarm devices.Some models
have a hush or temporary silence feature that allows silencing, typically by pressing a
button on the housing, without removing the battery. This is especially useful in locations where
false alarms can be relatively common (e.g. near a kitchen), or users might remove the
battery permanently to avoid the annoyance of false alarms, preventing the alarm from
detecting a fire should one break out. While current technology is very effective
at detecting smoke and fire conditions, the deaf and hard of hearing community has raised
concerns about the effectiveness of the alerting function in awakening sleeping individuals
in certain high-risk groups such as the elderly, those with hearing loss and those who are
intoxicated. Between 2005 and 2007 research sponsored by
the United States’ National Fire Protection Association (NFPA) focused on understanding
the cause of the higher number of deaths in such high-risk groups. Initial research into the effectiveness of
the various alerting methods is sparse. Research findings suggest that a low frequency
(520 Hz) square wave output is significantly more effective at awakening high risk individuals. Wireless smoke and carbon monoxide detectors
linked to alert mechanisms such as vibrating pillow pads for the hearing impaired, strobes,
and remote warning handsets are more effective at waking people with serious hearing loss
than other alarms.===Batteries===
Batteries are used either as sole or as backup power for residential smoke detectors. Mains-operated detectors have disposable or
rechargeable batteries; others run only on 9-volt disposable batteries. When the battery is exhausted a battery-only
smoke detector becomes inactive; most smoke detectors chirp repeatedly if the battery
is low. It has been found that battery-powered smoke
detectors in many houses have dead batteries. It has been estimated that in the UK over
30% of smoke alarms may have dead or removed batteries. In response public information campaigns have
been created to remind people to change smoke detector batteries regularly. In Australia, for example, a public information
campaign suggests that smoke alarm batteries should be replaced on April Fools’ Day every
year. In regions using daylight saving time, campaigns
may suggest that people change their batteries when they change their clocks or on a birthday. Some mains-powered detectors are fitted with
a non-rechargeable lithium battery for backup with a life of typically ten years, after
which it is recommended that the detector be replaced. User-replaceable disposable 9-volt lithium
batteries, which last at least twice as long as alkaline batteries are available. The US National Fire Protection Association
recommends that home-owners replace smoke detector batteries with a new battery at least
once per year, when it starts chirping (a signal that the battery is low), or when it
fails a test, which the NFPA recommends to be carried out at least once per month by
pressing the “test” button on the alarm.===Reliability===
A 2004 NIST report concluded that “Smoke alarms of either the ionization type or the photoelectric
type consistently provided time for occupants to escape from most residential fires,” and,
“Consistent with prior findings, ionization type alarms provided somewhat better response
to flaming fires than photoelectric alarms (57 to 62 seconds faster response), and photoelectric
alarms provided (often) considerably faster response to smoldering fires than ionization
type alarms (47 to 53 minutes faster response).”Regular cleaning can prevent false alarms caused by
the build-up of dust and insects, particularly on optical type alarms as they are more susceptible
to these factors. A vacuum cleaner can be used to clean domestic
smoke detectors to remove detrimental dust. Optical detectors are less susceptible to
false alarms in locations such as near a kitchen producing cooking fumes.On the night of May
31, 2001, Bill Hackert and his daughter Christine of Rotterdam, New York died when their house
caught fire and a First Alert ionization smoke detector failed to sound. The cause of the fire was a frayed electrical
cord behind a couch that smoldered for hours before engulfing the house with flames and
smoke. The ionization smoke detector was found to
be defectively designed, and in 2006 a jury in the United States District Court for the
Northern District of New York decided that First Alert and its then parent company, BRK
Brands, was liable for millions of dollars in damages.===Installation and placement===In the United States most state and local
laws regarding the required number and placement of smoke detectors are based upon standards
established in NFPA 72, National Fire Alarm and Signaling Code. Laws governing the installation of smoke detectors
vary depending on the locality. However, some rules and guidelines for existing
homes are relatively consistent throughout the developed world. For example, Canada and Australia require
a building to have a working smoke detector on every level. The United States NFPA code cited in the previous
paragraph requires smoke detectors on every habitable level and within the vicinity of
all bedrooms. Habitable levels include attics that are tall
enough to allow access. Many other countries have comparable requirements. In new construction, minimum requirements
are typically more stringent. All smoke detectors must be hooked directly
to the electrical wiring, be interconnected and have a battery backup. In addition, smoke detectors are required
either inside or outside every bedroom, depending on local codes. Smoke detectors on the outside will detect
fires more quickly, assuming the fire does not begin in the bedroom, but the sound of
the alarm will be reduced and may not wake some people. Some areas also require smoke detectors in
stairways, main hallways and garages.A dozen or more detectors may be connected via wiring
or wirelessly such that if one detects smoke, the alarms will sound on all the detectors
in the network, improving the likelihood that occupants will be alerted even if smoke is
detected far from their location. Wired interconnection are more practical in
new construction than for existing buildings. In the UK the installation of smoke alarms
in new builds must comply with British Standard BS5839 pt6. BS 5839: Pt.6: 2004 recommends that a new-build
property consisting of no more than 3 floors (less than 200 square metres per floor) should
be fitted with a Grade D, LD2 system. Building Regulations in England, Wales and
Scotland recommend that BS 5839: Pt.6 should be followed, but as a minimum a Grade D, LD3
system should be installed. Building Regulations in Northern Ireland require
a Grade D, LD2 system to be installed, with smoke alarms fitted in the escape routes and
the main living room and a heat alarm in the kitchen; this standard also requires all detectors
to have a mains supply and a battery back up.==Standards=====EN54 European standards===
Fire detection products have the European Standard EN 54 Fire Detection and Fire Alarm
Systems that is a mandatory standard for every product that is going to be delivered and
installed in any country in the European Union (EU). EN 54 part 7 is the standard for smoke detectors. European standard are developed to allow free
movement of goods in the European Union countries. EN 54 is widely recognized around the world. The EN 54 certification of each device must
be issued annually.====Coverage of smoke and temperature detectors
with European standard EN54====EN54-7: Smoke detector
EN54-5: Temperature detector SA: Surface area
Smax (square metres): Maximum surface coverage Rmax (m): Maximum radioInformation in “bold”
is the standard coverage of the detector. Smoke detector coverage is 60 square metres
and temperature smoke detector coverage is 20 square metres. Height from ground is an important issue for
a correct protection.===Australia and United States===
In the United States, the first standard for home smoke alarms, NFPA 74, was established
in 1967. In 1969, the AEC allowed homeowners to use
smoke detectors without a license. The Life Safety Code (NFPA 101), passed by
the National Fire Protection Association in 1976, first required smoke alarms in homes. Smoke alarm sensitivity requirements in UL
217 were modified in 1985 to reduce susceptibility to nuisance alarms. In 1988 BOCA, ICBO, and SBCCI model building
codes begin requiring smoke alarms to be interconnected and located in all sleeping rooms. In 1989 NFPA 74 first required smoke alarms
to be interconnected in every new home construction, and in 1993 NFPA 72 first required that smoke
alarms be placed in all bedrooms. NFPA began requiring the replacement of smoke
detectors after ten years in 1999. In 1999 Underwriters Laboratory changed smoke
alarm labeling requirements so that all smoke alarms must have a manufactured date written
in plain English. In June 2013 a World Fire Safety Foundation
report titled, ‘Can Australian and U.S. Smoke Alarm Standards be Trusted?’ was published
in the official magazine of the Australian Volunteer Fire Fighter’s Association. The report brings into question the validity
of testing criteria used by American and Australian government agencies when undergoing scientific
testing of ionization smoke alarms in smoldering fires.==Legislation==
In June 2010 the City of Albany, California, enacted photoelectric-only legislation after
a unanimous decision by the Albany City Council; several other Californian and Ohioan cities
enacted similar legislation shortly afterwards.In November 2011, the Northern Territory enacted
Australia’s first residential photoelectric legislation mandating the use of photoelectric
smoke alarms in all new Northern Territory homes.In the Australian State of Queensland,
from 1 January 2017, all smoke alarms in new dwellings (or where a dwelling is substantially
renovated) must be photoelectric, not also contain an ionisation sensor, be hardwired
to the mains power supply with a secondary power source (i.e. battery) and be interconnected
with every other smoke alarm in the dwelling so all activate together. From that date, all replacement smoke alarms
must be photoelectric. From 1 January 2022, all dwellings sold, leased
or where a lease is renewed must comply as for new dwellings. From 1 January 2027, all dwellings must comply
as for new dwellings.In June 2013, in an Australian Parliamentary speech, the question was asked,
“Are ionization smoke alarms defective?” This was further to the Australian Government’s
scientific testing agency (the Commonwealth Scientific and Industrial Research Organisation
– CSIRO) data revealing serious performance problems with ionization technology in the
early, smoldering stage of fire, a rise in litigation involving ionization smoke alarms,
and increasing legislation mandating the installation of photoelectric smoke alarms. The speech cited a May 2013, World Fire Safety
Foundation report published in the Australian Volunteer Fire Fighter Association’s magazine
titled, ‘Can Australian and U.S. Smoke Alarm Standards be Trusted?’ The speech concluded with a request for one
of the world’s largest ionization smoke alarm manufacturers and the CSIRO to disclose the
level of visible smoke required to trigger the manufacturers’ ionization smoke alarms
under CSIRO scientific testing. The US state of California banned the sale
of smoke detectors with replaceable batteries

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