(WHTM) — The U.S. Food and Drug Administration issued a safety warning against the use of some recalled at-home COVID-19 tests.

The FDA says SD Biosensor Inc. Pilot COVID-19 at-home tests, which are distributed by Roche Diagnostics, have been recalled over concerns of bacterial contamination in the liquid solution that comes in the test kits. The FDA is urging both consumers and health care providers to stop using the affected tests.

According to the FDA, direct contact with the contaminated liquid could pose a safety concern such as possible skin irritation or bacterial infection. The contamination could also affect the performance of the test, including potentially false results, the FDA says.

None of the impacted tests were distributed through the U.S. government’s Free at Home COVID-19 tests program.

Around 500,000 of the recalled tests were distributed to CVS Health, and around 16,000 went to Amazon. The FDA and Roche Diagnostics are working together to determine how many were sold to consumers.

Courtesy of SD Biosensor, Inc.

The FDA provided lot numbers of tests affected by the possible contamination:

53K38N1T153K4221T153K4292T1
53K38N2T153K4222T153K42A1T1
53K38N3T153K4223T153K42A2T1
53K38N4T153K4224T153K42A3T1
53K38N5T153K4225T153K42E1T1
53K38P1T153K4231T153K42G1T1
53K38P2T153K4232T153K42G2T1
53K38P3T153K4233T153K42H1T1
53K41T5T153K4261T153K42H2T1
53K41X1T153K4262T153K42L1T1
53K41X2T53K4271T153K42L2T1
53K41X3T153K4272T153K4361AC
53K4211T153K4273T153K4362AC
53K4212T153K4274T153K4392AC
53K4213T153K4291T1 
Courtesy of the FDA

The FDA is advising people with tests bearing the above lot numbers to throw the whole test kit in the “household trash” and not to pour the liquid down the drain. If the liquid comes into contact with your skin or eyes, you should thoroughly flush with lots of water.

The FDA also urges people to watch for signs of bacterial infection, such as fever, discharge, red eyes or other potential symptoms. If signs emerge, get medical attention.

Anyone with questions can email the Division of Industry and Consumer Education (DICE) at DICE@FDA.HHS.GOV or call 800-638-2041 or 301-796-7100.