Quote: (Originally Posted by
hrdubwd)
1 Sorb is meant to be damp at all times to work - i.e. water is present.
Of course. The quantity of water is important. None at all means no reaction, too much is a caustic cocktail.
Quote: (Originally Posted by
hrdubwd)
2 There is no reaction of sorb with water (that was done in manufacture) - see 1.
The Calcium Hydroxide dissolves in water. That means when there is too much water, the Calcium Hydroxide comes out of the carrier holding it, into the water, which then enters the breathing hoses.
Quote: (Originally Posted by
hrdubwd)
3 There are no fumes from the sorb. Getting it soggy can make no difference. - see 2. Smell comes from dust and reaction of alkali with other things.
4 There can be no early warning from taste or smell - see 3.
Agree.
Quote: (Originally Posted by
hrdubwd)
5 It is exceedingly unlikely that gases (toxic or otherwise) could be released from ptfe under normal low. temp circs, and certainly not in concentrations to worry about. It is used internally, surgically, for its inertness and lack of toxicity.
You are missing an important piece of information. Send me a PM with an email address, and I can send some detailed information on this. Off gassing is a serious problem. SINTEF have done considerable work on this, because diving umbilicals get contaminated. What happens in diving is the helium migrates into the porous plastic and then migrates out again bringing toxic chemicals with it. Furthermore the high PPO2 accelerates the ageing of these plastics and some of the breakdown products give such serious cause for concern that many organisations ban them or campaign to ban them. Such as the US Navy banning many of these plastics in hyperbaric and rebreather systems.
On your point 6, with all due respect, I would examine the facts first. Starting with SINTEF's publications on this topic. Considerable work has been done in this area that you should read up on.
Alex