Overbreathing the scrubber

[DiveSanta]

is it possible to "overbreathe" the scrubber? In other words, if you found yourself in heavy current or otherwise having to exert yourself heavily, can you increase the flow rate through the scrubber to the point where it's no longer effective? Or, in the alternative, does the scrubber create enough resistance where, after a point, you just can't draw more gas through it, so your work of breathing goes way up?

I have never dived a rebreather, and I can't ever remember seeing this issue discussed anywhere.

[Jack]

You can over breathe a scrubber to the extend that CO2 scrubbing capabilities are diminished/gone. You are then basically waiting to build up too much CO2 with all consequences thereafter. A scrubber passing through 0.5% CO2 is considered broken through.

There is not a scrubber I am aware of that works with breathing resistance to indicate over breathing.

I have two scrubbers with low WOB, breathing either of them is to me like breathing ordinarily at the surface. This WOB is the same at all depths and with all efforts I have been with them.

Basically you have to know how much time you have on a scrubber, how much you have used and keep a certain margin for unforeseen things.

As you know the amount of CO2 produced varies by person and work effort but if you keep control of your breathing pattern at all times, you can be fairly sure of scrubber duration.