An Arizona man died after he and his wife ingested a chemical in an attempt to prevent a coronavirus infection, Banner Health said in a press release. His wife is in critical care. Both are in their 60s.

The chemical — chloroquine phosphate — is commonly used to clean fish tanks.

During a press conference on Thursday, President Donald Trump touted chloroquine as showing "very, very encouraging early results" in treating COVID-19 and falsely stated that the Food and Drug Administration (FDA) was working "to be able to make that drug available almost immediately." The drug has been used to treat malaria.

Minutes after Trump made the false claim, FDA Commissioner Steven Hahn said a "clinical trial, a large, pragmatic clinical trial" would be required before making any determination on the use of chloroquine to treat the coronavirus.

In its press release, Banner Health advised against "the use of inappropriate medications and household products to prevent or treat COVID-19."

“Given the uncertainty around COVID-19, we understand that people are trying to find new ways to prevent or treat this virus, but self-medicating is not the way to do so,” said Dr. Daniel Brooks, Banner Poison and Drug Information Center medical director. “The last thing that we want right now is to inundate our emergency departments with patients who believe they found a vague and risky solution that could potentially jeopardize their health.”