Consumers and health care workers are advised "to stop using and toss out certain lots of recalled SD Biosensor, Inc. Pilot COVID-19 At-Home Tests, distributed by Roche Diagnostics."

According to the FDA, the agency has "significant concerns of bacterial contamination" in the liquid solution component of the kits. "Direct contact with the contaminated liquid solution may pose safety concerns and the bacterial contamination could impact the performance of the test," said the agency, issuing a "do not use" warning to consumers.

The contamination could have come from raw materials from a supplier, according to SD Biosensor.