RicodJour wrote:

*Zero* mention of any scientific evidence *whatsoever* that age alone
would render a smoke alarm inoperative. Absolutely NOTHING to suggest
the rationale behind the guideline of replacing them every ten years.

Are you *quite* sure about THAT? Perhaps *you* could contact the NFPA
(already capitalized) and ask to SEE their data. I'm *sure* that
statistically SPEAKING one could determine the *likelihood* of HALF of
the *inoperative* smoke DETECTORS being over TEN *YEARS* OLD. It is
*very* UNLIKELY that it would be a *random* occurrence.

Your words carry no more weight with the unseemly emphasis than
usual. The NFPA - silly folk with a predilection for creating
arbitrary standards - have absolutely no data with which to back up
their recommendation. You should write an angry letter. Use a lot of
emphasis to show you really mean it.


Correlation does not imply causation. Half the defective smoke detectors
being over ten years old may be due to other causes:

* They came from dirty homes and the dust-bunnies interfered with proper
operation. It's a fact that half the homes in America are dirtier than the
median.
* Ten years ago, there was a big influx of Chinese smoke detector circuitry
made with Melamine.
* ALL of the failed smoke detectors had their batteries removed to eliminate
the nagging chirp.

It's poor practice to make decisions based on assumptions about cause and
effect.

If one gets exercised over the "ten year = failure" business, here's an even
more shocking revelation: Virtually ALL of the failed smoke detectors were
colored white!

Beware.