Is ethidium bromide toxic?

Yes, ethidium bromide is highly toxic as a mutagen. This is because of its ability to bind with DNA, distorting the conformation and function of the DNA. Because of its intercalating nature, ethidium bromide is also suspected to be carcinogenic and teratogenic, although it has not been conclusively proven.

The toxic effects of ethidium bromide may be experienced if the substance is inhaled, ingested or absorbed through the skin. Acute exposure may cause irritation of the upper respiratory tract, eyes, skin, and mouth. Extreme care must be taken while handling, storing, and disposing contaminated items to minimize exposure.