Exposure to Soda Lime Dust during SCR/CCR dives

[NAND]

It seems my Hometown Kiel is not only producing submarines but studies as well which I'd like to share for some thoughts on it.

Exposure to soda-lime dust in closed and semi-closed diving apparatus. - PubMed - NCBI

This paper reveals an exposure to Scrubber-dust of 9.6mg/m³ while the condensate in the loop increases to a pH of 8.87

My own thoughts: To visualize this topic, I imagine a loop consumption of 20l/min for 60mins as a single, simple non-deco dive. Adding this up, I'll end at 1,2m³ which then makes 11,5 mg solids inhaled. Comparing this to a smoker who consumes a cigarette at 1mg per stick I imagine a single of my CCR dives to smoking half a pack of cigarettes. (Ok, thats a weird analogy and not directly comparable, i know...)

 

[northernone]

I'll enjoy reading and considering this.

 

[joshk]

Is the full paper available?

 

[fsardone]

Is the full paper available?

You can look upt the article on research gate and request the full text there ....

 

[dreamdive]

not heaving read the full article, there are two things to consider
1. Type of rebreather and if a dust filter was in place
2. type of sorb as some sorb is more dusty than other

 

[fsardone]

Also proper packing helps. Some useful packing tips in mastering rebreather by Jeffrey Bozanic.
In chapter 8 about canister filling he recommends filling outdoors in the breeze so the dust is blown away ... like chaff being separated from grain.

Cheers

 

[MegDiver792]

and you give lots of space for the sorb to fall (thus releasing dust as well) into the scrubber

 

[fsardone]

and you give lots of space for the sorb to fall (thus releasing dust as well) into the scrubber

Not my idea but I believe it has a lot of merit.
Also, since this book is a mandatory reading by (quite) a few instructors teaching CCR this opinion must be share.
The dust is mostly created in storage and transport of the big tubs (look at the bottom of the tub ...) so pouring in the breeze will get rid of that dust.
If you pour very close to the canister that dust will go into your scrubber.
Personally I pour twice: once from the 20 kg tub into the 5 kg tub I use to carry the sorb around and then fill the canister.
This will get rid of most of the dust created in transit.

Cheers

 

[BabyDuck]

(not about the topic, but i've been to kiel. stayed in trappenkamp for a few weeks, which is very close, and it was kiel week.)

 

[JohnnyC]

I always make sure I'm pouring sorb from height, preferably outside with a slight breeze. I'm also pretty diligent about using a cloth to wipe down everything post-fill to minimize dust. Just seems like prudence considering the caustic nature of sorb when wet.