(WJW) — As homes across the country begin receiving the free at-home COVID-19 antigen tests, a new warning is being issued about a potential hazard.

According to Poison Control, the extraction vial in many of the kits includes a chemical that acts as a preservative agent and could be harmful.

Sodium azide is a colorless, tasteless and odorless powder that has been used as a propellant in airbags and pest control agents, just to name a few. Poison Control officials say when swallowed, the chemical can cause low blood pressure, dizziness, headache and heart palpitations. In more severe cases, people can experience seizures or loss of consciousness and death may occur.

Poison Control officials say the amount of sodium azide in most rapid antigen kits is much lower than the amount expected to cause poisoning if swallowed by an adult. But they are warning that people should be aware the vials resemble small squeeze bottles or eye droppers. Some may accidentally confuse them with medications and apply the drops to their eyes or nose, which may cause irritation. It can also irritate skin or cause a chemical burn. The tests should be kept out of the reach of small children.

Rapid antigen tests work with a nasal swab to detect coronavirus. In most cases, results may be available in as little as 15 minutes, depending on the brand of test used. 

If you suspect someone has swallowed sodium azide, do not make the person vomit. For eye exposures, rinse the eyes for 15-20 minutes with warm tap water. For skin exposures, rinse the skin well with tap water. Immediately check the Poison Control online tool for guidance or call Poison Control at 800-222-1222. If someone has swallowed part of a rapid antigen test and is choking, call 911 immediately.