The National Capital Poison Center a/k/a Poison Control has issued the following statement:
As the pandemic continues, rapid-at home antigen testing has become an important tool for the early identification of COVID-19 infection. An antigen is a substance that triggers an immune response when the body encounters it. Rapid COVID-19 antigen tests detect specific antigens present on the surface of the coronavirus via a nasal swab. Results may be available in as little as 15 minutes, depending on the brand of test used. Because of this, rapid antigen tests can be used for early identification of COVID-19 infection at home. This helps with public health efforts to limit the spread of COVID-19, and is particularly important as many outpatient testing sites and hospitals are overwhelmed when cases of the virus surge in the community.
Because of recent efforts to expand the availability of at-home testing, rapid antigen tests are available online, in stores, and are being distributed in schools and by community sites. These test kits generally contain a nasal swab, an extraction vial and cap, and a testing card. While procedures may vary between brands, the testing process usually involves placing the nasal swab tip into both nostrils. This is followed by mixing the test swab with the contents of the extraction vial. This generates a chemical reaction that provides a positive or negative test result.
It is important to know that the extraction vial in many rapid antigen kits includes the chemical sodium azide as a preservative agent. The BinaxNow, BD Veritor, Flowflex, and Celltrion DiaTrust COVID-19 rapid antigen kits all contain this chemical. Sodium azide is a colorless, tasteless, and odorless powder that has been used as a propellant in automobile airbags, an herbicide, and a pest control agent. While it is now most frequently utilized as a laboratory preservative agent, sodium azide has also been used during the process of manufacturing beer, wine, and rubber. When swallowed, sodium azide can cause low blood pressure, dizziness, headache, and heart palpitations. In more severe cases, seizures, loss of consciousness, and death may occur. Sodium azide is a very potent poison, and ingestion of relatively low doses can cause significant toxicity. Fortunately, 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. However, the extraction vials do look like small squeeze bottles or eye droppers. Some people may accidentally confuse them with medications and apply the drops into their eyes or nose, which may cause irritation. People also may spill it on their skin which can cause skin irritation or chemical burns. Small children may accidentally swallow the contents of the vial or choke on the vial’s small cap.
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 webPOISONCONTROL® online tool for guidance or call Poison Control at 1-800-222-1222. Both options are free for the public, and available 24 hours a day. If someone has swallowed part of a rapid antigen test and is choking, call 911 immediately.
Maryann Amirshahi, PharmD, MD, MPH, PhD