Question Lifespan of open keg of Sofnolime

[LFMarm]

Hello,

Does the lifespan of a keg of Sofnolime change when opened? Here is what I found on DGX but it doesn’t really answer the question “after opening”:

When correctly stored, intact and unopened plastic containers of Sofnolime will maintain absorption capacity for five years. Sofnolime does not require any maintenance during storage but should be stored in a temperature range of 32 - 95°F (0 - 35°C).

 

[Mobulai]

When you close it again it should survive “indefinitely”; IDK about its own non CO2 driven breakdown (shelf life) but I assume this is independent of being opened or sealed
Essentially the answer is NO

Check out this thread, it refers to a paper that explores the concept:
Post in thread 'How long can you expose a scrubber to air?'
How long can you expose a scrubber to air?

 

[mr_v]

About 1-2 months. Then the keg is empty.

 

[inquis]

The trace amount of CO2 in ambient air enters the keg when opened, but is quickly reacted/removed and the reaction halted until opened again. I believe the impact on CO2 absorption capacity is negligible, as a single exhale has more CO2 than enters the keg when opened. Also, if your keg takes more than a year to empty, you likely have more pressing concerns.

 

[justinthedeeps]

Probably no producers, medical industry, nor divers are actually analytically testing the sealed material over years.
How many grams of CO2 permeates the tub material and cap seal over time? We don't know.

We'll probably only have polls and anecdotes.

A) What is the maximum number of years you have dived off the same tub of absorbent? (~1-2 years)
B) What is the oldest open tub you have dived from (by years since produced)? ('4+' years)
C) What is the oldest unopened tub you have ever opened and used? (same as B...)

Two unopened tubs are found--one was produced last year, another is a five year old unopened tub that was stored in a cool, dry garage. Do you throw away the 5yo unopened tub?

Is sorb from a half-empty, in-date tub that was opened two years ago (and probably closed firmly each time) safer than sorb from an unopened, six year old tub?

There are other Bayes-level factors contributing to how usable we should expect these tubs to be, like who opened the tub, how it was stored, how long/serious/challenging your next dive will be etc.

 

[Snusmumrik]

C) What is the oldest unopened tub you have ever opened and used? (same as B...)

1963 or 1964 year produced.

 

[Mobulai]

1963 or 1964 year produced.

When did you use that!?

 

[Snusmumrik]

When did you use that!?

Ahhh... Used it on early start of my dive career. Somewhat 15 years ago. So, when it was opened - it's already 45+ years old. It's cheap, sealed, stored in dry place, and work flawless.