The FDA issued a warning to consumers on Thursday over potential bacteria contamination affecting certain Covid-19 at-home tests.

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.

Specifically, the tests could be contaminated with Enterococcus, Enterobacter, Klebsiella, and Serratia bacterial species - the infection of which could cause illness in individuals with weakened immune systems, or those who have direct exposure to the contaminated liquid test solution via misuse, accidental spills, or “standard handling” of the product, the Epoch Times reports.

Aside from developing an infection, the contaminated products may also produce “false-negative” or “false-positive” antigen test results, the FDA said, which could lead to a variety of problems. For example, according to the FDA, a false-negative test could result in an individual seeking treatment for COVID-19.

SD Biosensor has initiated the recall for the at-home tests to certain retailers across the United States, according to the FDA announcement.

Some 500,000 tests were distributed through CVS Pharmacy as well as about 16,000 tests that were sent via Amazon. It’s not clear how many were sold to consumers, the FDA said, adding that it is “working with Roche” to determine the number. -Epoch Times

"Importantly, none of the impacted lots were distributed through COVID.gov/tests – Free at-home COVID-19 tests or as part of other federal testing programs," said the FDA. "If you received your tests through the COVID.gov/tests distribution or as part of other federal testing programs, they are not subject to this safety communication or product recall."

In a statement responding to the warning, Roche said that the recalled test kits can be identified by the lot number on the outer packaging and compared to a list of affected lot numbers.

"Dispose of the entire test kit in the household trash," reads an advisory. "Do not pour the liquid down the drainThe statement continues to warn that "direct exposure to the liquid in the tube through misuse or spillage could potentially lead to serious illness."

"If the liquid in the tube contacts your skin and eyes, flush with large amounts of water and if irritation persists, seek medical attention,” the company added. “Individuals performing the self-test may run the risk of direct contact with the contaminated liquid in the tube."

"The liquid is contained in an individual, ready-to-use, pre-filled and sealed tube, but a user may inadvertently come in direct contact with the contaminated liquid during opening the tube or handling of the open tube or while performing the test."