Smoke Detector Born On Date

[A/A Fuel GTX]

Do the born on dates on smoke detectors really mean anything? I realize that the recommended useful life is 10 years but is that from the born on date or the date the unit was installed?

 

[dhalleron]

From National Fire Alarm Code NFPA 72-2010:

14.4.8 Replacement of Smoke Alarms in One- and Two-Family
Dwellings.
14.4.8.1 Unless otherwise recommended by the manufacturer?s
published instructions, single- and multiple-station smoke
alarms installed in one- and two-family dwellings shall be replaced
when they fail to respond to operability tests but shall
not remain in service longer than 10 years from the date of
manufacture.

 

[A/A Fuel GTX]

From National Fire Alarm Code NFPA 72-2010:

14.4.8 Replacement of Smoke Alarms in One- and Two-Family
Dwellings.
14.4.8.1 Unless otherwise recommended by the manufacturer’s
published instructions, single- and multiple-station smoke
alarms installed in one- and two-family dwellings shall be replaced
when they fail to respond to operability tests but shall
not remain in service longer than 10 years from the date of
manufacture.

Thanks....But I wonder what can affect the life of these if they are stored in their original packaging? I can see once deployed where they are subject to the elements.

 

[mgookin]

Thanks....But I wonder what can affect the life of these if they are stored in their original packaging? I can see once deployed where they are subject to the elements.

I think it's more of a cost/ benefit or risk/ reward calculation.
Smokes are cheap.
Life is priceless.
Requiring the manuf. to date stamp the device is simple.
If we had installer dating them, who knows what we'd end up with.

 

[A/A Fuel GTX]

I think it's more of a cost/ benefit or risk/ reward calculation.
Smokes are cheap.
Life is priceless.
Requiring the manuf. to date stamp the device is simple.
If we had installer dating them, who knows what we'd end up with.

Agreed, but I assure you that they are in the out of sight, out of mind category anyway. How many calls do you receive asking for a complete smoke detector change out? The only time you hear about them is if they are annoying the consumer in some way. I'd still like to know how they degrade if kept in original packaging in a climate controlled environment. The gist of my post is if I have some brand new detectors with a born on date of July of 2005 stamped on them, they are considered obsolete in two years if they were installed for the first time today. Why, unless it's just a way for mfgr's to sell more products?

 

[steve66]

Thanks....But I wonder what can affect the life of these if they are stored in their original packaging? I can see once deployed where they are subject to the elements.

Ionization detectors use a very small amount of radioactive material. It might have something to due with the half live of this element. Although, I think its more likely the last post has the correct answer - its just easier to track the manufacture date.

But FWIW, from wikipedia;

Americium is the only synthetic element to have found its way into the household, where one common type of smoke detector uses ²⁴¹Am in the form of americium dioxide as its source of ionizing radiation.^[91] This isotope is preferred against ²²⁶Ra because it emits 5 times more alpha particles and relatively little of harmful γ-radiation. The amount of americium in a typical new smoke detector is 1 microcurie (37 kBq) or 0.28 microgram. This amount declines slowly as the americium decays into neptunium-237, a different transuranic element with a much longer half-life (about 2.14 million years). With its half-life of 432.2 years, the americium in a smoke detector includes about 3% neptunium after 19 years, and about 5% after 32 years. The radiation passes through an ionization chamber, an air-filled space between two electrodes, and permits a small, constant current between the electrodes. Any smoke that enters the chamber absorbs the alpha particles, which reduces the ionization and affects this current, triggering the alarm. Compared to the alternative optical smoke detector, the ionization smoke detector is cheaper and can detect particles which are too small to produce significant light scattering; however, it is more prone to false alarms.^{[92][93][94][95]}

 

[dhalleron]

Like rules in the NEC. It's a code requirement. You shall not ask why, just do it.

I think it has more to do with the fact that most residential smoke alarms don't get serviced or cleaned and tested as much as most commercial detectors do. If they are cleaned and properly tested I believe they can last just as long as commercial detectors.

A commercial smoke detector can pretty much stay in service forever as long as the sensitivity test is done and the detector is within specs.

Around 1993 I was doing sensitivity testing on commercial ionization type smoke detectors that were made in the early 1960s. The model number and date was hand written on them. Nearly all of those detectors tested fine using our calibrated equipment.

 

[GoldDigger]

The gist of my post is if I have some brand new detectors with a born on date of July of 2005 stamped on them, they are considered obsolete in two years if they were installed for the first time today. Why, unless it's just a way for mfgr's to sell more products?

The only halfway legitimate reason I can think of is that they want a cutoff to ensure that old smokes eventually will be replaced if the standards to which they are tested have changed and the old units are not guaranteed to met the new test requirement.
Putting a 10 year cutoff for all units is easier than trying to keep track of and notify about standards changes.

 

[A/A Fuel GTX]

So maybe circuit breakers, GFCI's, AFCI's, etc. should have expiration dates too. Just sayin'...........

 

[peter d]

Interesting, I thought it was because of the time it takes for the plastic to turn from white to yellowy color. :lol:

 

[PetrosA]

Two nights ago there was a fire in a building here in Lancaster. Fifteen people lived in the building. Four were killed in the fire, two more died in hospital today. The post fire inspection found that many (if not all of) the smoke detectors were not functioning properly. If this was a rental unit, then a city inspector's butt may be on the line as they're supposed to be inspected once a year. I suspect the ten year policy is to make it easier for local inspectors to force upgrades, rather than call in specialists to test the smokes with calibrated gear.

Lancaster allows the non-hardwired style sealed battery units for retrofit in rentals, which reinforces the 10 year cycle. So far it's the only large town I've worked in that allows that... :?

 

[GoldDigger]

... sealed battery units ....

To remove the temptation to the renters to take the battery out to power a radio? Or to provide a guaranteed service without being dependent on periodic battery replacements?

 

[PetrosA]

To remove the temptation to the renters to take the battery out to power a radio? Or to provide a guaranteed service without being dependent on periodic battery replacements?

Both, AFAIK. I still don't know whether I'd trust them in my house, but since our smokes need upgrading, I need to make a decision. Unfortunately, it's not wired for interconnected smokes, so the battery units would make my life a lot easier...

 

[haydenjsle]

Here's NFPA's main reason for requiring smoke "alarms" be replaced every 10 years--see link. IIRC this was also noted in the explanatory material in one of the older NFPA 72 code books--I don't think it is noted in the last several editions. I believe the secondary reason is that residential smoke alarms do not get serviced and tested at regular intervals as they should--whereas, commercial smoke "detectors" generally do. Obviously, regular service and testing results in much earlier detection of faulty units. I think this fact is also noted in NFPA 72 in the later editions.

IMO--its a good idea any way you look at it. If not for the afore mentioned reasons, then to take advantage of new technological advances in the units--better performance and increased safety. I don't write the codes--I just try to follow. There's good reasoning behind every code written. :happyyes:


http://www.kvfd.com/pdf/NFPA_replace_smoke_det_every_10.pdf

 

[kwired]

Ionization detectors use a very small amount of radioactive material. It might have something to due with the half live of this element. Although, I think its more likely the last post has the correct answer - its just easier to track the manufacture date.

But FWIW, from wikipedia;

Americium is the only synthetic element to have found its way into the household, where one common type of smoke detector uses ²⁴¹Am in the form of americium dioxide as its source of ionizing radiation.^[91] This isotope is preferred against ²²⁶Ra because it emits 5 times more alpha particles and relatively little of harmful γ-radiation. The amount of americium in a typical new smoke detector is 1 microcurie (37 kBq) or 0.28 microgram. This amount declines slowly as the americium decays into neptunium-237, a different transuranic element with a much longer half-life (about 2.14 million years). With its half-life of 432.2 years, the americium in a smoke detector includes about 3% neptunium after 19 years, and about 5% after 32 years. The radiation passes through an ionization chamber, an air-filled space between two electrodes, and permits a small, constant current between the electrodes. Any smoke that enters the chamber absorbs the alpha particles, which reduces the ionization and affects this current, triggering the alarm. Compared to the alternative optical smoke detector, the ionization smoke detector is cheaper and can detect particles which are too small to produce significant light scattering; however, it is more prone to false alarms.^{[92][93][94][95]}

Beat me to it, but I was going to mention the same thing. The half life of the radio active component in the detector would seem to be kind of important to reliable operation of the device, and this radioactive decay starts the moment that component is made, not when the unit is put into service.

 

[mgookin]

Too many people come out of their home in a body bag.
Dying over a $20 appliance is senseless.


Does anyone on here unplug their coffee maker when it's not being used? Those things are notorious for spontaneous combustion.

 

[texie]

Kidde has chosen to force the issue. After first power up it tracks years. At 7 years it chirps every 30 seconds, forcing you to replace it.

 

[iwire]

So maybe circuit breakers, GFCI's, AFCI's, etc. should have expiration dates too. Just sayin'...........

I bet soon enough they will. :roll:


Check out this document, I think it supports your thoughts.

http://www.google.com/url?sa=t&rct=...=dl7nNUQDYknvT0_zA3Rwvg&bvm=bv.48705608,d.dmg

 

[GoldDigger]

Beat me to it, but I was going to mention the same thing. The half life of the radio active component in the detector would seem to be kind of important to reliable operation of the device, and this radioactive decay starts the moment that component is made, not when the unit is put into service.

But with a half-life of 400+ years, it does not seem reasonable to limit the unit to only 10 years from time of manufacture. And this applies only to ionization type smoke detectors. Photoelectric smoke detectors are limited instead by the lifetime of the light source, which in turn will vary only with time in use rather than time since manufacture.

 

[kwired]

But with a half-life of 400+ years, it does not seem reasonable to limit the unit to only 10 years from time of manufacture. And this applies only to ionization type smoke detectors. Photoelectric smoke detectors are limited instead by the lifetime of the light source, which in turn will vary only with time in use rather than time since manufacture.

I did not claim to know how much impact on performance the half life has in 10 years, but it kind of makes sense that it will be a limiting factor in some way, even for a device that has not been placed in service yet but the radioactive material is decaying even though it is not being used.