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Re: "breathable" bags

> Date: Thu, 29 Apr 1999 16:20:21 -0700
> From: "David Robinson" <robinson at ichips_intel.com>
> Subject: "breathable" bags
> Bob Dixon wrote:
> > If you pump pure O2 into a bag before shipping, the O2 will escape the bag
> > anyway, because the bags we use for fish are selectively permeable to O2
> and
> > CO2.  This shopkeeper, while sincere and concerned enough to pass up a
> sale,
> > is not properly informed.  I have kept fish for up to a week in bags
> without
> > a problem at this time of year.  It only becomes a concern when
> temperatures
> > rise up past about 85F, as the O2 levels then begin to drop due to lower
> > solubility.
> While breathable bags are certainly available now, many fish stores do not
> go through the added expense of using the bags that are sufficiently
> permeable
> to support fish life for extended periods of time.  I submit this response
> not
> to be argumentative,

And I, too, wish to point out, non-argumentatively, that fish *can* live
indefinitely in the standard 1.5 mil poly bags we all use to ship fish.
They are already oxygen permeable enough that I know of a killy that
lived for over a month in a forgotten bag.

There are commercially available bags with *enhanced* permeability, but
I find them useless, for they need to be filled all the way, kept out of
spillage, etc., and generally make shipping too expensive or hazardous.
They are way too fragile for fish with spines, BTW.

The rules for regular poly bags and enhanced-permeability bags are quite
different. I have lost more fish from getting them in the enhanced bags
than I have for any arriving in regular thickness bags. Only thicker
bags, like freezer bags have killed as many fish for me. The reason
freezer bags are 4-7 mils thick is because thinner bags leak oxygen and
permit freezer burn! Thick bags don't "breathe."

Bob Dixon was right on. I have written articles on how to ship fish
safely. E-mail me privately for a copy of one. I have experience
shipping fish or eggs to Japan, NZ, Argentina, Africa, and Europe. I
expect live arrival if I follow *all* the rules.


Wright Huntley, Fremont CA, USA, 510 494-8679  huntleyone at home dot

                      Stop passing new laws!
       Repeal some dysfunctional ones. It will do far more good.* 
*Substance-abuse laws and other victimless-crime laws for example.