ATLANTA — The Centers for Disease Control and Prevention (CDC) issued a health alert Saturday, warning against the use of non-pharmaceutical chloroquine phosphate to treat COVID-19.

Chloroquine phosphate is a chemical for aquarium use because it kills algae. It's commercially available for purchase at stores and online.

The national health alert comes after a Phoenix-area man died and his wife was hospitalized after taking the chemical they believed could help protect against coronavirus.

Last Sunday, the couple, both in their 60s, took the aquarium-use chemical, and within 30 minutes, the two experienced severe side effects, requiring admittance to a nearby hospital. The man died, and his wife remains under critical care, according to a hospital spokesperson.

The product in their possession was in powder form inside a 2.2-lb. container and labeled "for Ornamental Fish Use Only."

A family friend told Phoenix station KNXV-TV that the couple decided to mix the powder with a drink because they had heard the president and other officials touting the drug chloroquine as a possible treatment for COVID-19.

The CDC says there are currently no FDA-approved drugs that can treat COVID-19.

"Pharmaceutical chloroquine phosphate and hydroxychloroquine sulfate are approved by the FDA to treat specific medical conditions, such as malaria, lupus, and rheumatoid arthritis. Currently, these medications are being studied and evaluated as treatment for COVID-19; however, their efficacy to either prevent or treat this infection are unknown," the CDC statement read.

The CDC says it is also aware of unconfirmed media reports that these commercially available aquarium-use chemicals may be out of stock due to potential increased demand by the public.