As Americans have started receiving government-issued COVID-19 test kits, poison control centers are cautioning people about a potentially toxic substance in the kits.

The Cincinnati Drug and Poison Information Center reports seeing an uptick in accidental exposures to the chemical sodium azide which is an ingredient used as a preservative in a liquid used to trigger the chemical reaction that detects the presence of coronavirus.

The most common calls to poison centers have been about children finding the small bottle containing the liquid and putting it in their mouth or spilling it on themselves. In adults, there have been cases of "container confusion," with the bottle being mistaken for eye drops.

The types of test kits vary, but they generally contain a swab, testing card, and an extraction vial containing the liquid.

If swallowed, sodium azide in it can cause a headache and lower blood pressure. In large amounts, it can cause seizures.

Poison control experts say that the amount of sodium azide in these products is small. In most cases so far, children have just had a taste of the liquid and they have done okay.  But the weight of the person and the amount of liquid ingested make a difference in how severe a reaction they may experience.

To prevent accidental poisonings from the COVID-19 home test kits, poison control centers recommend the following tips:

  • Store the kit "up and away," out of the sight and reach of children and pets.
  • Leave the kit sealed until needed and throw it away immediately after use.
  • Make sure to read and follow the instructions on the package before using.