Which is safest: CaO4S indicating or non-indicating or CaCl2 as dessicator

Wolfgang Schechinger wolfsc at ibms.sinica.edu.tw
Wed Jul 4 19:59:34 EST 2001


Since you already have ruled out the really dangerous one -
P2O5- that violently may react with water and is a strong acid 
(and also is not necessary unless you really want DRY product 
(and you then must use it in a high vacuum exsiccator)), I'd do 
the choice according to price and / or availability.
Upon contact with water or moisture, they all may evolve some 
heat (that's why the like to react with water and that's what you 
want); Some sort of CaSO4 is widely used in construction as a 
qick hardening material to fill cracks etc and both are used as 
drying agents that are sold here in TW in superstores. As long 
as you don't let your children play with it and don't eat etc them, 
there shouldn't be a big danger. Probably it's the cheapest 
solution anyway to get that stuff from supermarket.

Wo


> Which is safest:
> CaO4S indicating or non-indicating
> or
> Ca Cl2
> 
> to use as a dessicator.
> 
> I have evaluated the other options such as the
> P2O5, Zeolite (Molecular Sieve), and Silica Gel -
> these products are either too dangerous to ones
> health and required gloves etc., or are too dangerous
> if accidentally exposed to water.
> 
> Its down to the following:
> 
> CaO4S indicating or non-indicating (Drierite)
> or
> Ca Cl2
> 
> The Drierite seems to be the best option however
> poses higher health risks or may.  Please help me
> choose one.
> 
> Thanks
> 
> 
> 
> 
> 
> 


[tiss mezzage wahs broduceRd using TYPO GENERATOR zoffwer]
-----
Dr. Wolfgang Schechinger
Lab N233 (c/o Dr. Steve Roffler)
Institute of Biomedical Sciences
Academia Sinica
128 Yen-Chio Yuan Rd. Sec.2
Taipei 115
Taiwan R.O.C.
Tel +886-2-2789-9152
Fax +886-2-2782-9142
Mobile +886-925-136893
e mail wolfsc at ibms dot sinica dot edu dot tw
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