What really caught Girlawhirl's eye about this particular email was that it claimed Johns Hopkins was the source of the information. So as any good sleuth would do, she went right to the source to find out if the claims were true. As it turns out they aren't—for the most part.

In an article published by Johns Hopkins Bloomberg School of Public Health, Dr. Rolf Halden says the myth about freezing water in plastic bottles is just that—a myth. According to Dr. Halden, there are no dioxins in plastic and freezing actually has the opposite effect on the release of chemicals—it prevents it. He also said consumers should be more concerned about what's in the water they're drinking than what's in the plastic because water bottling companies are not held to the same high standards as municipal and city water systems.

He did say, however, that there is some truth to the claim about microwaving food in plastics. The doctor says whenever plastics are heated there is some kind of chemical transfer and the best way to prevent the transfer is to simply follow heating instructions—they're there for a reason. He also says it's better to cook foods in ceramic and heat-resistant glass containers, which are particularly good for the microwave.

Girlawhirl read more about dioxins online at the Johns Hopkins Bloomberg School of Public Health's website.