100% natural rubber
The worst plastic used in children's toys, including teethers, bath toys and dolls, is polyvinyl chloride, or PVC, which creates dioxins in production and often contains phthalates, chemical softeners used to make the plastic soft and pliable. Considered hormone disruptors" and linked with asthma and respiratory problems, phthalates can migrate out of toys and onto the hands (and into the mouths) of children." -the Green Guide.com