Tag Archives: chlorine

Story on animal testing confuses plastics issues.

Story on animal testing confuses plastics issues.

Posted by Evan Beach at Apr 16, 2010 10:00 AM | Permalink

The Valley Vanguard draws attention to some interesting fronts in endocrine disruption, but confuses issues related to plastics and chemical additives.


A March 22 article in the Valley Vanguard reports on a clash between the animal rights organization People for the Ethical Treatment of Animals (PETA) and researchers at Saginaw Valley State University (SVSU). The reporter’s description of the SVSU research program provides an excellent, succinct summary of the differences between studies that focus on animal death or reproduction and those that explore fetal development in a more detailed way.

The article does erroneously link dioxins and the phthalate plasticizer DINP to water bottles, though.

Most water bottles are made from polyethylene terephthalate (PET) plastic (recycling #1), which is highly unlikely to contain dioxins or dioxin precursor chemicals. Urban legends have spread the myth that extreme cold or heat can release dioxins from water bottles, but PET contains no chlorine, the essential ingredient required for formation of the environmental contaminants. Dioxin formation is linked to burning of chlorine-containing PVC plastic (recycling #3), which is used in many everyday products but rarely water bottles.

The effects of DINP are also discussed in the article. DINP is a phthalate plasticizer commonly used as an additive for PVC plastic, not PET, so it should not be found in an ordinary water bottle. The confusion may arise from the similarity in names: PET contains building blocks called terephthalates and DINP is an orthophthalate. But as far as harmful effects are concerned, the connection stops there. DINP, DEHP, and other orthophthalates are associated with the hormone-disrupting effects described in the story. Readers who wish to avoid DINP exposure should stay away from soft, flexible PVC products (e.g. vinyl shower curtains, floor tiles, and children’s toys).

The PETA versus SVSU conflict is given a balanced presentation. However, it could have been better and more interesting if the story had further explored the larger question about non-animal testing methods. To provide greater depth into the issue would have informed readers about why other methods couldn’t be used for this particular research. One way to do this would be to include the viewpoint of a third party who doesn’t have a stake in the dispute.