The Ministry of Defence says that an ingredient found in insect repellent can protect against Covid-19 - here’s how

Citriodiol is found in many insect repellents (Photo: Shutterstock)

Inspect repellents that contain an ingredient called ‘Citriodiol’ could be used to help defend against the coronavirus, according to researchers at the Defence Science and Technology Laboratory.

In an eight page paper from the Porton Down based lab, the efficacy of Mosi-guard, a Citriodiol based spray, was tested on plastic and artificial skin.

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What is Citriodiol?

Citriodiol is a naturally sourced active ingredient produced from steam distilled Eucalyptus citriodora oil.

The chemical compound is found in a range of insect repellents, including Mosi-guard, which was the subject of the Defence Science and Technology Laboratory testings.

It’s been reported that Citriodiol is already known to kill other types of coronavirus.

It’s also understood that insect repellent containing Citriodiol and not containing another ingredient called Deet is considered effective.

Defence secretary Ben Wallace said that the spray was issued to British armed forces on the basis that the spray wouldn’t do any harm, and could potentially offer an extra layer of protection, even though there was no proof it worked, Sky News reported.

What did the researchers find?

The report states that the Defence Science and Technology Lab (DSTL) “was tasked by the Surgeon General to determine the level of anti-viral activity of Mosi-guard Natural spray against Covid-19 virus, of which Citriodiol is an ingredient”.

It’s explained that “two experimental approaches were adopted” - one being the assessment of the anti-viral activity of the product when applied directly to the virus as a liquid drop, the other being the assessment of the product following its application to latex synthetic skin.

The DSTL says: “One minute liquid suspension test indicated that Mosi-guard Natural has anti-viral activity against SARS-CoV-2 England-2 isolate if mixed with the virus in the liquid phase.

“Additionally, viral studies on latex indicated that Mosi-guard Natural had antiviral activity against SARS-CoV-2 England-2 isolate.”

Is Citriodiol effective against Covid-19?

While the report indicated that the insect repellent appeared to reduce the presence of the Covid-19 virus, it’s important to note that the experiment work undertaken by DSTL “has not been externally peer-reviewed”.

While Jeremy Quin, defence minister, said that the research found that the spray “can kill the virus”, the DTSL itself was more cautious.

In one test, the lab stated that there “was some loss of recoverable virus” on synthetic latex skin an hour after it had been treated with the spray.

However, some virus was still recoverable over a four-hour period.

It’s unclear whether the spray would have any additional benefits beyond frequent handwashing, the use of alcohol based hand sanitisers and personal protective equipment.

The research paper was shared, Quin said, “so others can take forward additional research to confirm and expand on [the] findings”.