Munchkin
Munchkin is a plastics company first: the overwhelming majority of its cups, bottles, and feeding tools are molded polypropylene and other BPA-free plastics, and the brand's messaging centers on "BPA-free" rather than plastic-free. A handful of products pair a stainless steel body with a plastic lid, rim, and valve, but even those keep plastic squarely in the drink path. BPA-free here means the specific additive is gone, not that plastic has left the cup.
How clear are their specs?
Listings reliably state "BPA-free" but rarely name the specific resin (polypropylene) for each part, and the drink-contact rim and valve get far less emphasis than the spill-proof and dentist-recommended messaging.
Products to avoid
Documented so you know what to skip — each still has a full breakdown and sources.
