Bonnie,
Hospitals are supposed to be following standards for safe practice.
Using plastic storage bags for any infant in the hospital is NOT
following safe practice standards!!  You need to get a copy of the Human
Milk Bank Assoc. of N. America's standards/recommendations.  Maybe if
you go from a safe practice angle people will listen to you.  Have a
talk with your infectious disease nurse to express your concerns.  I'll
bet you'd have an ally there!  Keep trying.
Edie Armstrong, BSN, IBCLC, Fairfax, VA