Washington – Walmart has recalled nearly 10,000 cases of apple juice from U.S. stores after finding potentially harmful levels of inorganic arsenic.

The U.S. Food and Drug Administration upgraded the recall to a more urgent level on Friday after originally announcing it on August 15. The new classification states that the affected product may cause temporary health effects but is unlikely to cause serious or permanent medical problems.

The recall affects 9,535 cases of Great Value brand apple juice sold in 25 states, Puerto Rico and the District of Columbia. Florida-based manufacturer Refresco Beverages US Inc. voluntarily recalled the contaminated six-packs of 8-ounce juice bottles after discovering levels of the chemical contaminant that exceeded industry standards.

A Refresco spokesman did not immediately respond to emails seeking comment on Sunday.

“The health and safety of our customers is always our top priority,” Walmart spokeswoman Molly Blakeman said in a statement. “We have removed this product from our affected stores and are working with the supplier to investigate.”

According to the National Institutes of Health, very small amounts of both inorganic and organic arsenic are found in many foods. Testing is done routinely because slightly elevated levels of either form can cause symptoms such as vomiting, abdominal pain, diarrhea, numbness, and muscle cramps.

According to the FDA, inorganic arsenic is more toxic to humans than the naturally occurring form of the mineral arsenic, and the health effects of exposure are more severe. The U.S. Environmental Protection Agency has classified inorganic arsenic as a carcinogen.

The levels found in the recalled apple juice bottles are so low that the FDA does not believe they have such serious health effects.

The FDA has not received any reports of possible illnesses related to the apple juice recall.