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Andy Nguyen
By Andy Nguyen July 29, 2021

COVID-19 testing swabs won’t change your DNA, contrary to claim on Facebook

If Your Time is short

  • Ethylene oxide gas is used to sterilize around half of the medical equipment that is used across the United States. The equipment is then aerated so that any residual ethylene oxide can be released and dissipate.
  • The gas is a known carcinogen and can cause health issues if a person is exposed to a high concentration, but any trace amounts of ethylene oxide on a cotton swab would not be enough to cause harm or change a person’s DNA.

A video on Facebook is throwing doubt on the safety of COVID-19 tests, claiming the swabs used in the tests are covered in a cancer-causing chemical that will change a person's DNA.

In the video shared July 18, a man appears to be at a drive-thru COVID-19 testing site where he’s handed a testing kit by a woman off-camera and he begins to examine the cotton nasal  swab that’s included.

The man says the swab contains "sterile EO," and he asks the woman if she knows about the substance.

"Ethylene oxide is the number one ingredient used in antifreeze. For cars and machinery, et cetera," the man claims in the one-minute video. "Ethylene oxide is a mass carcinogen and a mutagen. So it'll give you Hodgkin’s lymphoma and, in females, greatly increase the chances of breast cancer."

The man says ethylene oxide messes with a person’s DNA and it "literally changes the structure of the building blocks of your own body."

"You can look it up, that’s going to kill, that’s actually killing people," he tells the woman. The video ends with the man declining to take the test and driving away.

The video appears to have originated on the social media platform TikTok.

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

Ethylene oxide is considered a carcinogen and a mutagen (a chemical or physical agent that changes an organism's DNA), and it is used in the production of antifreeze. But the man in the video misrepresents its use in sterilizing medical equipment such as cotton swabs and misleads about its impact on public health.

Featured Fact-check

Medical use of ethylene oxide

Around 50% of all medical items in the United States are sterilized using ethylene oxide gas, according to the federal Food and Drug Administration. 

The gas is used on equipment that would be damaged or harder to sterilize using other techniques such as heating or steaming.

Items containing certain plastics, metals, glass and gauze are likely sterilized with the gas, according to the FDA. Following sterilization, items are then aerated so that any remaining ethylene oxide is released.

Although short-term exposure to high concentrations of ethylene oxide gas can cause health problems such as headaches, nausea and breathing problems, the trace amounts of gas that may be left on an item like a cotton swab are not enough to trigger any health issues, including cancer, according to the Environmental Protection Agency.

The residual amount of ethylene oxide is also not enough to cause any mutagenic effects on people; using a treated swab to test for COVID-19 won’t change a person’s DNA. Such damage would occur only after long-term exposure to the gas, the EPA said. 

A 2016 study on the effects of ethylene oxide on rayon and cotton swabs used in DNA collection found that the amount of gas remaining on the items was well below any measurable levels three weeks after sterilization.

Our ruling

A video shared on Facebook claims that the ethylene oxide used in COVID-19 testing swabs "literally changes the structure of the building blocks of your own body."

The swabs and many other types of medical equipment are sterilized using ethylene oxide gas. The gas is considered a carcinogen and a mutagen, but any traces of the gas left on a cotton swab after sterilization would be below measurable levels and harmless. 

A person wouldn’t have their DNA damaged or develop cancer by using a swab. 

We rate this claim False.

Our Sources

Facebook post, July 18, 2021

Tiktok post, July 17, 2021

Centers for Disease Control and Prevention, Ethylene Oxide (EtO): Evidence of Carcinogenicity, accessed July 27, 2021

Centers for Disease Control and Prevention, Ethylene Oxide, accessed July 27, 2021

Food and Drug Administration, Ethylene Oxide Sterilization for Medical Devices, accessed July 27, 2021

Centers for Disease Control and Prevention, Ethylene Oxide "Gas" Sterilization, accessed July 28, 2021

Environmental Protection Agency, Frequent Questions: Health Information About Ethylene Oxide, accessed July 28, 2021

Science & Justice, "Investigation into ethylene oxide treatment and residuals on DNA and downstream DNA analysis," January 2017

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COVID-19 testing swabs won’t change your DNA, contrary to claim on Facebook

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