On Wed, 7 Dec 2011 14:30:55 -0800 (PST), "hr(bob) "
wrote:

On Dec 7, 12:03*pm, "Doug" wrote:
I've got a couple of these cartridges still sealed in packaging. *Is
there a shelf live for these unopened new cartridges?

What is going to spoil????

They have charcoal in them. Half life of carbon is less than 6000
years, so I wouldn't hang on to one for more than 2-3000 years.

Jim