People don’t usually think twice about buying bottled water. Feeling thirsty while you’re out? Just head to a nearby shop and buy some bottled water. In addition to being an easily accessible form of hydration, it’s also believed that bottled water is safer and healthier to drink compared to tap water. However, a recent study says otherwise.

Bottled water is purchased at extremely high rates, especially in places like Flint, Michigan where there is currently a water crisis and people have no choice but to turn to bottled water for clean water. However, bottled water may not be as safe as you think. A test conducted by the California nonprofit Center for Environmental Health found that two bottled water brands—Starkey, owned by Whole Foods and Peñafiel, owned by Keurig Dr. Pepper—contained levels of arsenic higher than tap water. The level of arsenic is so high that this violates state guidelines.

California law states that high levels of arsenic can cause cancer and reproductive harm. Therefore, products that violate the recommended state levels of arsenic need to be labeled with a warning.

“Customers typically purchase bottled water at exorbitantly high costs with the assumption that it is safer and healthier to drink than tap water, unaware that they are ingesting an extremely toxic metal linked to birth defects and cancer,” Michael Green, the organization’s CEO, said in a statement.

Studies also show that high levels of arsenic can cause organ damage and hormone disruption, especially in children as their bodies are still developing.

According to the study: “Direct exposure can affect mental and physical development […] Arsenic can even harm an unborn child as a result of exposure to pregnant women or women likely to become pregnant. Arsenic in drinking water can cause an increased risk of heart disease, including high blood pressure and diabetes. The metal is also what is known as an ‘endocrine disrupting chemical,’ which means even small doses can wreak havoc on a human’s hormone system.”

This study corroborates independent findings released earlier this year by Consumer Reports. The findings stated that the same brands of bottled water had nearly double the federal limit of arsenic levels in their water.

Keurig Dr. Pepper stopped production of their bottled water, Peñafiel, for two weeks after the release of the initial Consumer Reports study, with proposals to improve their water filtration. As of now, the Food and Drug Administration has yet to recall either of the brands of bottled water.

Starkey is sold at Whole Foods, while Peñafiel is sold at Walmart, Target, and other vendors.

Bottled Water Your bottled water may not be as safe as you think. A study has found that two brands of bottled water contain levels of arsenic higher than tap water. Photo: Pure Water Purifiers / Flickr