A story about hard plastic drinking bottles containing bisphenol A leaching notable amounts of the controversial chemical into people’s bodies that appeared on page A1 of Friday’s Post-Dispatch raised questions from readers as to exactly which bottles had BPA.

One reader wanted to know if the chemical could be found in disposable plastic bottles, such as those holding soft drinks and water. The answer is, no. The bottles in question are the hard plastic type that are reusable and are generally sold empty.

Of specific concern has been the use of the chemical in the manufacture of baby bottles and sippy cups. Hundreds of studies have linked the chemical to breast and prostate cancer, diabetes, heart disease and other health problems. The studies have shown young children to be especially susceptible to the effects of BPA.

However, the Boston Globe story points out “BPA is used in hundreds of everyday products. It is used to make reusable, hard plastic bottles more durable and to help prevent corrosion in canned goods such as soup and infant formula.”

So exactly which products have BPA packaging is a little hard to trace. This is why some cities and states have decided to ban the sale of some products using BPA. Chicago earlier this month enacted a ban of baby bottles and sippy cups that have BPA, following a similar action carried out by the state of Minnesota. Other cities, including Boston, are looking at similar measures.

Some retailers, including Wal-Mart, already have vowed to stop selling bottles and containers made with BPA, the Chicago Tribune reports. Some manufacturers, including the nation’s leading baby-bottle makers, also have started to market products labeled as “BPA-free.”

While BPA is not found in disposable water bottles you buy at the store, a report on the U.S. News and World Report’s website points out that other chemicals can be found in those bottles.

Deborah Kotz, a senior writer for the magazine, wrote in her blog that a new study from Goethe University in Germany found 78 percent of the samples taken from plastic disposable water bottles contained etrogen like compounds, still unidentified, that “could have the same harmful effects of BPA.”

But Kotz also points out that the study found the same compounds in 33 percent of the samples taken from water sold in glass bottles.

Patricia Hunt, a reproductive biologist and geneticist at Washington State University, told Kotz that the chemicals could have shown up in the glass bottles because the water itself may have contained the chemicals even before bottling.

“Birth control pills, hormone therapy medications, and a host of contaminants can all get into our water supply, and we haven’t figured out a way to aaffordably filter them out,” Hunt said.