Researchers have warned against drinking water from a bottle if it had been left somewhere warm for a long time.
According to the study by University of Florida, since plastic water bottles are made from polyethylene terephthalate, when heated, the material releases the chemicals antimony and bisphenol A, commonly called BPA.
While the U.S. Food and Drug Administration has said BPA is not a major concern at low levels found in beverage containers, it continues to study the chemical's impacts, and some health officials claim that the chemical can cause negative effects on children's health.
UF soil and water science professor Lena Ma led a research team that studied chemicals released in 16 brands of bottled water kept at 158 degrees Fahrenheit for four weeks, what researchers deemed a "worst-case scenario" for human consumption.
Ma's study found that as bottles warmed over the four-week period, antimony and BPA levels increased.
Of the 16 brands, only one exceeded the EPA standard for antimony and BPA. Based on the study, storage at warm temperatures would seem to not be a big problem, Ma said. However, more research was needed to know if other brands were safe.
Drinking that water occasionally won't be dangerous, but doing so regularly could cause health issues, she said. And it wasn't just water containers, as more attention should be given to other packaged drinks such as milk, coffee and acidic juice, Ma said.
The study is published in the journal Environmental Pollution.