On 2007-12-09 02:15:59 +0000, Derek Geldard said:

On Sat, 08 Dec 2007 23:36:33 +0000, Peter Parry
wrote:

Claims of 20-25 years are common

"25 years" Seems to have the status of a "Golden Number" in the
vocabulary of those promoting green technology, for whatever motive.
You know something along the lines of the "7 Seas", "7Deadly Sins"
and "7 Wonders of the World".

Curiously CFL's have been claimed to last 25 years, but we had one
fail yesterday, the third within a week. :-(

It's like those wineboxes. It says on the box that once open they
last for 3 months, but they don't.....