The U.S. Food and Drug Administration (FDA) announced today that Nova Diabetes Care has voluntarily recalled its glucose test strips. The recalled strips are marketed under the “Nova Max Blood Glucose Test Strips” and “Nova Max Plus Glucose Meter Kits” brands.

The FDA estimates that the recall affects up to 62 million Nova test strips manufactured from December 2011 and April 2013. The products were sold online shipped to countries across the world, including the U.S., Canada, Argentina, Peru, Chile, the Dominican Republic, Jamaica, Puerto Rico, Congo, Saudi Arabia, Finland, Belgium, Germany, and the U.K.

The test strips had reportedly been contaminated during the manufacturing process. As a result, the strips could, under specific conditions, report higher-than-accurate blood glucose levels – an error that could cause diabetics to receive an improper dose of insulin.

“It is important that patients using these test strips discontinue their use immediately,” said Alberto Gutierrez, director of the Office of In Vitro Diagnostics and Radiological Health in FDA’s Center for Devices and Radiological Health. “A false reading could result in patient harm and delay critical care.”

The FDA is urging customers to immediately stop using the recalled strips. Nova is directing customers to contact the company to confirm whether their test strips are affected by the recall. The company is offering free replacement strips for the return of the recalled strips.