It started as a joke, but the question ‘if a fart can make it through jeans, how can a cloth mask save you from coronavirus’ has turned into a chemistry lesson.
Trevor Makal, a professor at the University of Virginia, took to Twitter to share his take on the question – and it all comes down to the size of the molecules that make up both the smell in a fart and the coronavirus, and how they pass through materials.
He explains that farts smell because they contain methanthiol (CH3SH), which is about 0.4nanometers (nm) in diameter.
Meanwhile, most viruses range from about 20 to 400 nm – and the current coronavirus sweeping the world is 60 to 140 nm in size.
‘The difference in sizes of the COVID-19 virus and a common odorant in farts is 2-3 orders of magnitude (100–1000 times the diameter of the smaller methanethiol),’ Makal writes in the tweet.
It started as a joke, but the question ‘if a fart can make it through jeans, how can a cloth mask save you from coronavirus’ has been turned into a chemistry lesson
Trevor Makal is a chemistry professor at the University of Virginia and took to Twitter to answer the questions
He began by explaining what a fart is made up of, which is mostly methanthiol – a particle that cases the smell
Makal begins the Twitter thread by explaining the different size of molecules that make up both the smell in a fart and the coronavirus. Farts contain methanthiol (CH3SH), which is about .4nm in diameter.
Makal explains that an N95 mask – with its tight weave and has multiple layers – capable of filtering about 95 percent of particles up to 300 nm.
So the mask will block the virus, but the stink from passing gas will still get through.
Makal notes that the benefits of wearing a mask depends on the fabric and how it is made, but also suggests that having some ‘form of barrier between an infected individual and a healthy individual is far superior to open air allowing for the transfer of virus.’
He continues to explain that most viruses range from about 20 to 400 nm, but the current outbreak sweeping the world is 60 to 140 nm
Trevor Makal, a professor at the University of Virginia, took to twitter to share his take on the question, stating that an N95 mask is capable of filtering out most particles the size of 300 nanometers (nm).
‘While the benefits of a specific mask will depend on the fabric and construction of the mask (not to mention how it is worn), having some form of barrier between an infected individual and a healthy individual is far superior to open air allowing for the transfer of virus between those individuals,’ Makal writes.
‘Lastly, to argue that “since I can smell a fart through a mask, there’s no point in wearing a mask to protect me against viruses” is like securing a medieval castle with a gate to keep out invading horsemen but arguing that because roaches can still enter that there is no point in having a gate.’
‘Clearly you have not considered that the horseman is the greater threat.’
Makal also explains how an N95 is specifically made to block particles from entering the body
Makal also adds a little humor with an analogy on why you should wear a mask to protect yourself from viruses
Although Makal does not specifically say to wear a mask, the analogy about blocking a castle suggests that is the point of the thread
It started as a joke, but the question ‘if a fart can make it through jeans, how can a cloth mask save you from coronavirus’ has been turned into a chemistry lesson
The Centers for Disease Control and Prevention has advised all Americans to wear cloth masks or other face coverings if they go out in public.
While the purchase of N95 masks has been restricted, as they are needed for healthcare workers and frontline staff battling the disease, people are encouraged to wear a covering over the face to stop the spread of the disease.
Health officials believe wearing masks would reduce the risk of people not showing symptoms from spreading the virus.
But Dr. Deborah Birx, who coordinates the day-to-day administration response to the virus, cautioned people should not consider masks as a guarantee of protection.
‘We don’t want people to feel like I’m wearing a mask, I am protected, and I’m protecting others. You may be protecting others, but don’t get a false sense of security that that mask is protecting you exclusively from getting infected because they were other ways that you can get infected because the number of asymptomatic and mild cases that are out there,’ she said at the White House briefing.
She advised people to continue social distancing practices and to wash their hands.
Simple cloth masks – or scarves or bandannas – have been recommended for when people go to the grocery store, for a walk or are outside.