British soldiers have reportedly been given insect repellant to protect themselves from COVID-19.
The UK government’s Defense Science and Technology Laboratory published a study in a laboratory showing that the citriodiol-based spray can kill SARS-CoV-2, the coronavirus that causes COVID-19.
We are all looking for new ways to get the best protection against COVID-19.
Just because a product can be used safely in its current form doesn’t necessarily mean that it offers safe or adequate protection against COVID-19.
What is Citriodiol?
Health authorities around the world are promoting mosquito repellants to protect against mosquito-borne diseases.
But they don’t work by killing the virus mosquitoes that spread. They prevent the mosquitoes from biting us by blocking a mosquito’s ability to pick up the smells that help them find us.
Read more: Can mosquitoes spread the coronavirus?
There are dozens of different insect repellent formulations available, but most of the recommended products contain one of just a few different active ingredients.
The most common are diethyltoluamide (commonly known as DEET) and picaridin (also known as icaridin). There are also a wide variety of products that contain herbal ingredients.
Citriodiol is a new addition to the world of commercial insect repellent formulations, but there is very strong evidence that it provides effective protection against mosquito bites.
The chemical name for citriodiol is p-menthane-3,8-diol (commonly referred to as PMD) and is derived from lemon-scented gum (Corymbia citriodora). Although citriodiol comes from plants, it is considered to be chemically repellent like DEET and picaridin.
In Australia, the Australian Pesticide and Veterinary Medicines Agency monitors their use. If you have a citriodiol-based insect repellant, it will say “Lemon Eucalyptus Oil” which is what sets it apart from other oil-based repellants like tea tree.
There is no doubt that citriodiol-based repellants provide protection against mosquito bites, and health officials across Australia should routinely recommend them to reduce the risk of mosquito-borne disease.
But could this product repel both COVID-19 and mosquitos?
Cameron Webb (NSW Health Pathology)
Citriodiol and Coronavirus
The UK government’s Defense Science and Technology Laboratory looked at two ways citriodiol can kill SARS-CoV-2.
First they used citriodiol as an antiviral agent and applied the product directly to the virus in the laboratory. And second, they used it as a surface treatment for synthetic latex skin (designed so that the product is applied directly to human skin).
The first set of experiments showed that the insect repellent, when used in high concentration, killed the virus.
In the second experiments, application of the insect repellent to the synthetic latex skin reduced the amount of virus detected after four hours. However, the virus was not completely destroyed.
Read more: We know how long the coronavirus survives on surfaces. Here’s what it means for managing money, food, and more
We need more research to understand how exactly citriodiol could kill the virus. The process can be similar to that of hand sanitizer and other disinfectant products.
These preliminary results are encouraging but are intended to serve as a basis for future peer-reviewed research. You shouldn’t be a reason to recommend the use of insect repellants containing citriodiol to help prevent COVID-19.
Could existing citriodiol formulations be used safely?
It is important to note that there are strict warnings on the use of citriodiol-based repellants. They should not be used on children under 12 months of age and, like many other repellants, can cause eye or skin irritation. You definitely shouldn’t drink it.
This product can potentially be used as an antiviral or disinfectant. However, for such purposes we require alternative registration, packaging and instructions. This can mean a completely different registration process that involves other government agencies like the Therapeutic Goods Administration.
This is because it’s not just about what’s in the product, it’s also about how it’s used. If someone were to use an insect repellent as frequently as a hand sanitizer, the risk of a side effect would potentially increase.
Read More: The Best (and Worst) Ways To Control Mosquito Bites
There have been examples where products with different uses have been combined and require different instructions to ensure that they are used safely and effectively.
Mosquito repellants that contain sunscreen may pose a higher risk if they are used primarily for sun protection. Sunscreens should be used more frequently and in larger amounts than insect repellants.
The risk of adverse health effects from the use of insect repellants is small, but excessive use should be avoided. These types of products that combine insect repellant and sunscreen are restricted in some countries.
Better to stick to social distancing, hand hygiene, and wearing a mask than reaching for the nearest insect repellent if you want to avoid COVID-19.