Washing bottles in boiling water produces extremely high levels of ‘gender bending’ chemical BDA.

People who wash plastic bottles with boiling hot water and re-use them could be exposing themselves to BPA, an environmental estrogen shown to affect reproduction and brain development in animal studies, scientists have warned.

According to researchers at the University of Cincinnati (UC), cleaning bottles in boiling water releases the chemical 55 times more rapidly than exposure to hot water. The risk is no higher whether the container is new or old.

The team filled new and used bottles with water at room temperature for a week and measured the concentration of BPA in the liquid.

The bottles were then cleaned using boiling water, resulting in the production of drastically higher levels of BPA. The rate of release increased from 0.2 to 0.8 nanograms per hour to 8 to 32 nanograms per hour after exposure.

Belcher, UC associate professor of pharmacology and cell biophysics and corresponding study author, commented: “Previous studies have shown that if you repeatedly scrub, dish-wash and boil polycarbonate baby bottles, they release BPA. That tells us that BPA can migrate from various polycarbonate plastics, but we wanted to know if ‘normal’ use caused increased release from something that we all use, and to identify what was the most important factor that impacts release.”

BPA is one of many man-made chemicals classified as endocrine disruptors, which alter the function of the endocrine system by mimicking the role of the body’s natural hormones. Hormones are secreted through endocrine glands and serve different functions throughout the body.
 
The chemical is widely used in products such as reusable water bottles, food can linings, water pipes and dental sealants. There is no proof it affects people, however, according to Belcher there is: “A very strong suspicion in the scientific community that this chemical has harmful effects on humans.”

The findings are reported in full the 30 January 2008 issue of journal Toxicology Letters. 

By Natasha Piscitelli