DEBRA'S ANSWER:

It actually doesn't make much difference in terms of what is in contact with your milk. The plastic is polyethylene, whether it is in a plastic bottle or a paper milk carton.

Here's an article that explains how milk cartons are made from start to finish: How Products Are Made: Milk Carton.

Environmentally, actually, without doing a full lifecycle analysis, I would say that the plastic milk bottle would have less of an environmental impact. Since it is just one material, it's easier to recycle. And no trees are used to make the plastic bottle, as are used for the paper carton.

Back in 1989, the Food and Drug Administration (FDA) announced that highly toxic dioxin was leaching from the bleached paper used to make milk cartons. This came from the interaction of chlorine bleach with the wood pulp in the paper. The FDA said the milk was safe, but it directed the manufacturers of the cartons to shift within three years to processes that would drastically reduce the leaching, and manufacturers agreed.

A study done in New Zealand found that the mean concentration of dioxin in breast milk in the 1988 survey was 5.12 ng/kg fat and for the 1998 survey was 1.22 ng/kg fat. That's an 80% reduction. Which shows that there has been an overall reduction of dioxin exposure.

Should we assume that today there is no dioxin leaching from paper milk cartons? I don't think we can make that assumption. I called Organic Valley, a national provider of organic dairy products and they said that they do not use bleached paper in their milk cartons, so no dioxin. However, we don't know if other, particularly non-organic products, use unbleached or bleached paper. You would have to call the manufacturers of the milk available in your area to find out. One could make a reasonable assumption that if the dairy product within the carton is organic, the carton is probably made from unbleached paper. But I would call to find out.

There is, of course, no dioxin leaching from polyethylene or from glass bottles (which is my personal favorite packaging and what I buy whenever it is available to me).

Debra :-)