Polyethylene bags

Normally we try to avoid plastics materials which have been treated with
anti-stats and slip agents. Why do we not seem to be concerned about
these materials on the polyethylene from which bags are made? Is this
because one should only use polyethylene bags for enclosed storage in
dry climates? Is there a potential problem of fatty acids or other
substances forming on the inside of polyethylene bags used to protect
objects from environmental fluctuations, dirt, and insects in humid
climates? (Let us ignore for the sake of argument the potential of
condensation within the bags in case of sudden temperature change.) Or
is it just that it is difficult to ascertain from suppliers' catalogs
whether or not these substances are present, and it is easier to assume
that archival suppliers supply only archival materials? Picky minds
would appreciate opinions.

Lisa Mibach

                                  ***
                   Conservation DistList Instance 8:3
                  Distributed: Tuesday, June 21, 1994
                        Message Id: cdl-8-3-005
                                  ***