For a number of the preservatives there is more alarmist material out
there than there is actual data.  It was either for BHA or BHT that Dr.
Bruce Williams years go pointed out on the FML (I think it was the FML,
but I think in the years that precede the archives, and I wish I'd kept a
copy.) that not only were the test rats given mammoth doses, but that the
types of malignancies increased were types ferrets don't usually get,
whereas at least one type that ferrets more often get was actually
decreased.

Usually, the things that preservatives stop from growing in food are
much more dangerous than the preservatives themselves.

-- Sukie (not a vet, and not speaking for any of the below in my
private posts)
Recommended health resources to help ferrets and the people who love
them:
Ferret Health List
http://www.smartgroups.com/groups/ferrethealth
FHL Archives
http://ferrethealth.org/archive/
AFIP Ferret Pathology
http://www.afip.org/ferrets/index.html
Miamiferrets
http://www.miamiferret.org/fhc/
International Ferret Congress Critical References
http://www.ferretcongress.org
[Posted in FML issue 5287]