[Noisebridge-discuss] how to evaluate a shipping bag that claims to be a water filter?

[Sean Cusack]

Just based on the pore size, you should definitely hold back any microbial
life forms. They are on the order of um or fractions of um, not nanometers.

The thing that I'd still be concerned about is chemical contaminants. Peeps
typically use a carbon filtration setup to trap and remove trace
contaminants, and I don't see one of those in there. Maybe the assumption is
that the waters which people will be filtering won't contain many small
organic contaminants? I'm not sure how valid that assumption is.

So, that's probably where I would start - I'd answer: in water that a third
world country would typically be filtering, are there small molecule
organics in there in addition to just bacteria? If the answer is no, then
the filter would work (i.e. I'd drink water from it). If the answer is yes,
then I'd put it through a brita after I put it through the bag filter, then
drink it :).

Sean

On Fri, Feb 25, 2011 at 11:15 AM, John Adams <jna at retina.net> wrote:

> It's called a microscope and/or a water test kit.
>
> -j
>
>
> On Fri, Feb 25, 2011 at 11:13 AM, jim <jim at systemateka.com> wrote:
> >
> >    can anyone provide pointers for evaluating the
> > life-sack, advertised to be used as a bag for
> > shipping grains and after receiving the grains the
> > recipients can use the bag as a 15nmeter filter,
> > which purportedly passes only water.
> >
> >
> http://inhabitat.com/life-sack-solves-drinking-water-issues-for-the-third-world/
> >
> >
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> > https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss
> >
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