H.A.
C.,
Look for my post on this site about Bisphenol-A, a chemical that leaches into plastic baby bottles. I received MANY helpful links from Moms on Mamasource. Born Free are one of the best plastic bottle manufacturers and I think that on this link they mention other nipples that fit them...Good Luck!
http://zrecs.blogspot.com/2007/07/z-report-bisphenol-in-p...