COVID-19 swab tests have been sterilised in Ethylene Oxide.
Evidence in humans indicates that long-term exposure to ethylene oxide increases the risk of cancer of the white blood cells, including non-Hodgkin lymphoma, myeloma, and lymphocytic leukemia. Studies also show that long-term exposure to ethylene oxide increases the risk of breast cancer in females.
On page 22 of “Your step-by-step guide for COVID-19 self-testing” (NHS Test and Trace) Ethylene Oxide is listed as the sterile medium.
Ethylene oxide (EO) gas is commonly used to sterilize medical devices. A major concern is the amount of residue that may remain on or in the device and be available in the body.