Molecular sieve (Zeolite) and "The Big C".

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Wiggsy

Contributor
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Location
Mt Eliza; Melbourne; Australia
# of dives
I’ve just had some news from “Airdive”, a company that manufactures High Pressure air-filling compressors and Low pressure “Hookahs” that concerns me greatly. For the past 20 or more years, it has been standard practice to fill air filters for Hookah Systems (and many High Pressure SCUBA airfilling compressors) with Activated Charcoal and Molecular Sieve (Zeolite). But I have just heard from Airdive that they no longer supply Zeolite as it is "carcinogenic".

I’ve done quite a bit of research and, yes, it appears to be widely reported that it is linked to Mesotheleomia (sp?) when inhaled. This would be a real issue if filters are subject to vibration which can reduce to zeolite granules to the point where fine dust is produced - the fibres produced are similar to asbestos fibres. I guess dive shops have more stable filter banks, but I fear for every abalone or commercial diver that goes out in rough seas, and subjects the filter bank (usually attached to the compressor) to crushing impacts and vibration. It surprises me that this has not been more widely publicised as there could be far reaching implications for commercial divers that use SSBA.

I’m just wondering if anyone else may have heard anything. I’ve probably done a few hundred dives on my “Hookah” over the last 20 years and, yes, it is a bit of a worry, but my exposure has been minimal to commercial divers. Ironic that something carcinogenic when inhaled has been used for air filtration purposes – it absorbs moisture, dust and oil. But at what cost?

Cheers,
 
That is one of the reasons to buy prepacked filter cartridges. The beads are loaded and kept tight with some sort of a spring device to keep them from moving around even in the most turbulent of areas. And if you are the kind to hand pack your own, then this is also a reason to change the filter pads every time, pack tight and buy the beads from a reputable company that doesn't use cheap, dusty, Chinese import junk.
 
Use activated alumina instead?
You are 100% correct, Activated Alumina works great with lower pressures. Silica gel also works good for higher pressures but Mole sieve is the most effective and if handled correctly I don't think it is a problem. If it was, I think that we would have had allot more reported cases of lung diseases related to this by now. The same thing can be said for compressor oils that contain diesters.
My motto, "keep diving until you can't breath anymore."
Have fun out there,
ZDD
 
I’ve done quite a bit of research and, yes, it appears to be widely reported that it is linked to Mesotheleomia (sp?) when inhaled.

Can you provide some links to the literature you found? I have never heard of anything but asbestos causing mesothelioma (it is a pretty rare form of lung cancer afterall) and I am not finding any literature on this purported connection.
 
Mole sieve isn't a good choice for L.P. filtration, as has been mentioned. You are more likely to have a chemical fire with a properly packed filter, than having dust pass through the pads from any of the chemicals. Fires inside a filter tower are extremely rare, but they do happen and are generally the result of operator error and/or poor maintainence.
 
Zeolite as it is "carcinogenic".

But at what cost?

Cheers,

Wiggsy.

To the best of my knowledge there is only one source for Non carcinogenic molecular sieve used by the military for hyperbaric chamber air production for BSEN 8478 quality and oil free oil less breathing air compressor filters for use to BS 12021 with additional compliant to the EN 8478 nitrox production standard.

Its £15 GBP per kg and has been discussed here on the forum many times. I guess it unfortunately gets in the way of of the
money making business so your not fully informed.

But been used on all European oil free oil less breathing air and gas plants for the last 15 years

Enclosed the same subject discussed in 2008 for reference. Iain Middlebrook



http://www.scubaboard.com/forums/co.../251567-filter-modification-assistance-2.html



I should add:
In which you will note it refers back to a 2006 British blog on the same subject.

I guess seven years for the USA diving industry to start to finally begin to realise the implications of using
a legally dangerous industrial grade chemical for human breathing purposes and systems however well
some suggest your existing disposable (throw away) cartridge stack suppliers felt and polyester pads filter it.

There is and always has been an available and suitable carcinogen free alternative. Its more expensive.
But so is an American class legal action I hear.

It is what we call over here, a no brainer, but is again surprising the scant regard divers in general take
with there breathing gas quality and production method and process

Whatever next you ask, oxygen entrained into oil lubricated compressors.........never I tell you.
No one in this American centric diving industry is that stupid. LOL



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OK.....thanks. I agree that we tend to be rather casual about our air supply. Some great information, but my concern is regarding Conventional lubricated Low pressure systems used for Hookah...Here in Australia, oil free compressors have not really taken off and are still very expensive and limited in availability with only low output units. In any case, I'd rather simply find a safer filter medium rather than spend the bucks on a new compressor! I think the recommendation of activated alumina is a good one for LP SSBA (Surface Supplied Breathing Apparatus) and I will follow up on that. Much appears to depend on the stability of the filter bank - Hookah compressors tend to have filters attached to the frame - this subjects them to masses of vibration that could produce settling and dust. Combine that with the pounding a vessel can take in high seas and there are a couple of factors that concern me. "Hookah" compressors in Australia are, I guess, pretty poorly regulated (actually no regulation) and it is almost impossible to get air tested. But I shudder tho think what filtration was like 30 years back, when it was common practice to stuff filter packs with sanitary napkins! I have over the last 20 years, done hundreds of Hookah dives, and around 1000 SCUBA (Hookah is not always suitable - depending on depth and circumstances). After longer Hookah dives I am usually abnormally fatigued, often with a severe headache and occasionally a mild fever. I attribute this to Salt Water Aspiration syndrome - related to the type of diving (wriggling around upside down in ledges hunting crayfish is damned hard work!) These hard working dives expose the diver's fitness and tend to magnify any shortcomings with equipment - our Airdive regulators (the Industry standard for Hookah diving in Australia) tend to breathe a little damp. But for anyone that hasn't tried it, consider giving Hookah a go - it is a great way to dive for certain purposes and sites.



---------- Post added January 25th, 2013 at 02:18 PM ----------

Can you provide some links to the literature you found? I have never heard of anything but asbestos causing mesothelioma (it is a pretty rare form of lung cancer afterall) and I am not finding any literature on this purported connection.

Mesothelioma - Cancer Types, Causes, Symptoms and Diagnosis
Nov 16, 2012 ... Asbestos exposure is the primary risk factor for mesothelioma. Others include
Radiation, Zeolite and SV40. Read more in this section.
Mesothelioma - Cancer Types, Causes, Symptoms and Diagnosis
There are various references to Zeolite and Mesothelioma.
 
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If you go back enough years in Australia before you started using mPa on your pressure gauges and importing cheap cast aluminium blocks from italy and china like this lot. There was your own home grown Oz compressor firm that made a lovely heavy duty cast iron block the original LP "Clisby" hookah block. Now 30 years later they are pale reflections with some sand casting from India.

But I think there is a need to differentiate first between:
1. Medium cost Surface supplied (SSBA) for full air range
2. Low cost Hookah shallow diving
3. Micro cost yacht hull inspection pumps

Then look at the compressor block design itself, piston diameter, RPM, rod and liner material, particulate wear carry over material due to high piston speed and oil choice with high temperature oil break down, oil mist carry over for starters then look into ambient air temperature, heat and cooling considerations.

All this needs to be factored into your filter chemical choice before you look at the chemical matrix, chemical mesh size, dwell time, cartridge diameter x length.The chemical you choose will also only remove those contaminates its designed to remove another considerations would be CO removal by catalytic conversion if using a petrol (gas) or diesel engines.

Then there is the water vapour condensate IMHO most hookah suppliers are pretty clueless on design most I have played with condense too much water in the main umbilical and thats the aerosol gunge you breath, again another simple example of design care and attention.

I tend to use (S.France) two umbilicals the first a short one to act as a cooling coil over the side in a U shape then back on deck to a water separator tower to collect all the condensed water, then into the micronic filtration (no chemicals) before going into the main diving umbilical. The heat sink hose is also weighted so it sinks (not too deep) but just enough to get into the deeper cooler water as its too hot like bath water sometimes on the moorings. Cheap simple and effective.

The main point is that as most of the pollutant from the compressor is water, I simply don't see the point in overcoming your chemical tower prematurely with masses of water as in the first 20 minutes it just killed your filtration chemical.

Similar idea used on some HP systems to remove water by mechanical separators than waisting valuable chemicals using a back pressure regulator or priority valve but you need much more pressure differential to make them effective. Hence the cooling coil cheap simple and effective, with the only drawback is they only work on the bigger pump blocks not those micro pumps. Iain Middlebrook
 



Mesothelioma - Cancer Types, Causes, Symptoms and Diagnosis
Nov 16, 2012 ... Asbestos exposure is the primary risk factor for mesothelioma. Others include
Radiation, Zeolite and SV40. Read more in this section.
Mesothelioma - Cancer Types, Causes, Symptoms and Diagnosis
There are various references to Zeolite and Mesothelioma.
You do realize that you need to grind/pulverize the 13x absorbent and inhale the fibers right? And even that relationship is dubious since as mentioned, only the Zeolites native to Turkey have been liked to lung cancer. High quality 13x is not coming from Turkey, so you are mixing up different minerals. 13x molecular sieve is synthetically made, not mined.
 
https://www.shearwater.com/products/teric/

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