The Keurig Dr Pepper company today announced a recall of an unspecified volume of its Peñafiel brand unflavored mineral spring water because an independent laboratory found “volative levels of arsenic” in samples.

The company reported the unflavored spring water was imported from Mexico. All date codes of all unflavored Peñafiel mineral spring water products, including  600-millimeter and 1.5-liter bottles, are covered by the recall, according to the Keurig Dr Pepper company recall notice posted today by the Food and Drug Administration. The notice did not include any other identifying information.

“Water quality tests of Peñafiel samples conducted by an independent laboratory on behalf of Keurig Dr Pepper detected arsenic at levels that exceeded the FDA’s bottled water standards for mineral water of 10 ppb,” according to the company’s notice.

“Arsenic is found in nature, including in aquifers that are the source of mineral water and wher levels can vary over time. Keurig Dr Pepper has recently installed enhanced filtration systems at its facilities that produce Peñafiel, and the product now being produced is well within regulatory guidelines.”

Peñafiel is a small brand in the U.S., according to the company, and quantities “are very limited,” given that Keurig Dr Pepper has already begun to withdraw the products from the market. The company reported having notified retailers. It will work with them to remove the product from the market.

Although it is naturally occurring, arsenic is toxic to humans and other animals if consumed in high enough concentrations and/or over long enough time periods. It can cause a variety of conditions and is associated with several diseases, according to the Centers for Disease Control ad Prevention.

Infants, young children, older adults and people with weakened immune systems are more susceptible than healthy adults to serious problems when exposed to arsenic.