Scrubber longevity

[kombiguy]

If I take a new pre-packed scrubber cartridge, unwrap it, install it in my Poseidon Se7en, and keep the loop closed, how long will it be safe to use?
The same question for the pack-it-yourself scrubber? Once packed and installed,with the loop closed, is there a time limit on when it may be used?

 

[kombiguy]

Nevermind. I found the answer. It's 12 hours.

 

[jgttrey]

Can't speak to Poseidons, but 12 hours makes no sense. As long as the scrubber is stored in dry, airtight conditions, it shouldn't make any difference whether it is in the original container or been relocated to your canister.

I certainly don't dump my sorb and repack if I dive 2 hours one day and intend to dive two hours the next day, and if I'm horsing around locally, I have no problem popping a partially used canister in a drybag and using it the next week.

 

[kombiguy]

I agree that it sounds somewhat odd. However, that's what Sofnolime says.

 

[michael-fisch]

God, for the last 5 years I've been doing it all wrong! I'm gonna die!.
I fill the scrubber on each of my 3 rebreathers when it needs replacing and mark on a piece of tape attached to the rebreather the usage of the current scrubber.
Sometimes the sorb stays in the scrubber for 9 months before I use it enough to have to replace it (Bail Out Rebreather is a perfect example) and it hasn't killed me yet.
Cannot understand the difference between storing sorb in a closed off rebreather and storing it in a closed off original cannester - and doubt anybody else can either.
So, I'm not going to change my SOP and continue to not see a valid reason to change.

Michael
(Of course if I die tomorrow, that would have been a valid reason to change.)

 

[davehicks]

Short Answer: As long as the unit is sealed and stored in appropriate environmental conditions (heat & humidity) it will last just as long as it did in the original packaging. Same story if you seal up a partially used scrubber. In fact the worse thing you can do to scrubber material is let it desiccate and dry out as the water content in the sorb is required for the intended chemical reaction.

Several rigorous scientific studies run in laboratory environments have demonstrated this conclusively. I've shared the link to one study below. It's a short read and very much worth your time to read if you have come to this discussion topic.

A closed loop assembled rebreather than can pass a pos/neg check is just as good as a sealed zip lock bag, and is explicitly discussed in the study here.

Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters
Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters