Why BPA-free plastic bottles?

Why should you be concerned about plastics?
PVC, the most toxic plastic, is the type commonly used in soft children’s products such as bath toys,
squeeze toys and teething rings. Phthalates are added to make the PVC soft and squishy for use in
infant toys that are chewed and sucked primarily to relieve teething irriattion.
The toxic components in the PVC plastic used in these toys are not stable: the chemicals can leach
out. These chemicals can be consumed by children when they suck or chew on the plastic and can
show up in their bloodstream. There is concern in the scientific community that these chemicals may
be linked to cancer and interfere with the reproductive system and development.
Studies have shown that these chemicals are hormonally active and may interfere with hormone
systems that regulate growth and reproductive development in children.

The Dangers of Plastics
Bisphenol A was first synthesized in 1891, the first evidence of its estrogenicity came from
experiments in the 1930’s feeding BPA to rats. Another compound invented during that era,
diethylstilbestrol, turned out to be more powerful as an estrogen, so bisphenol A was shelved… until
polymer chemists discovered that it could be polymerized to form polycarbonate plastic.
Unfortunately, the ester bond that links BPA monomers to one another to form a polymer is not
stable and hence the polymer decays with time, releasing BPA into materials with which it comes into
contact, for example food or water. Bisphenol A is now deeply imbedded in the products of modern
consumer society, not just as the building block for polycarbonate plastic (from which it then leaches
as the plastic ages) but also in the manufacture of epoxy resins and other plastics, including
polysulfone, alkylphenolic, polyalylate, polyester-styrene, and certain polyester resins.

Its uses don’t end with the making of plastic. Bisphenol A has been used as an inert ingredient in
pesticides (although in the US this has apparently been halted), as a fungicide, antioxidant, flame
retardant, rubber chemical, and polyvinyl chloride stabilizer. These uses create a myriad of exposures
for people. Bisphenol A-based polycarbonate is used as a plastic coating for children’s teeth to
prevent cavities, as a coating in metal cans to prevent the metal from contact with food contents, as
the plastic in food containers, refrigerator shelving, baby bottles, water bottles, returnable containers
for juice, milk and water, micro-wave ovenware and eating utensils.

Experiments with mice reveal that chronic adult exposure to bisphenol A causes insulin resistance.
Insulin resistance in people leads to Type II diabetes and congestive heart failure, and is part of the
modern epidemic of ‘metabolic syndrome.’ The exposure levels used were within the range that
people experience regularly.

Researchers investigating endocrine disruption had focused primarily on behavioral and reproductive
consequences. But over the past few years, it’s become clear that some of the synthetic chemicals
that disrupt the endocrine system also induce weight gain. What’s more, production of these
chemicals closely tracks the rise of obesity.
http://en.wikipedia.org/wiki/Bisphenol_A