HI All,
What I learned about the freezer bag issue from my CLE course is that there
is a possibility of the plastic leeching out into the milk, thereby
contaminating the milk.  Since there have been no studies done on this (that
I know of) is it worth the risk to use them without being sure?  I mean, who
wants to feed their baby plastic?  The milk bags made by BF friendly
companies like Medela and Mother's Milk Bags (are there others?  I don't
know) are designed specifically for the storage of EBM, and the plastics
don't leech into the milk.
When I have a mom who insists on using the disposable type of milk bags
(playtex type) that are totally inapropriate for freezing, I tell them to
double bag and place the sealed bags in freezer bags.  This way, the milk is
protected from the freezer bag and the milk is also protected by the freezer
bag at the same time.
Hope this helps!
Jay
(who hasn't figured out why the plastic would leech in the first place, but
doesn't want to take any chances with liquid Gold!)