What do underpants and face masks have in common?


Do you ever consider from which material your underwear is made of? I honestly don’t. But the great thing about our Isala project is that we get a lot of inspiration from our participants and social media. For example, we were contacted by Lore Janssens from Oh Yaz, a sustainable clothing brand that wants to empower women. She is convinced that we pay too little attention to our underwear material. She started an impressive search for the ideal substances for people and nature. And who knows, maybe we can search together for substances that are also ideal for your microbiome. That is why we asked in our most recent questionnaire if you could also give your underpants’ material. 

We have known for a long time that each of us leaves a unique microbial fingerprint on our garments, also from our own research. For example, we helped visual artist Katelijne De Corte for her project 11.05 with her precious jeans’ microbial analysis.  

Whether there is a link between the fabrics we wear and our skin’s health or our intimate areas has almost not been studied. 

You might think this is a trivial topic that ‘serious scientists’ wouldn’t want to get involved with. But the questions are alive and are indeed relevant and important to our Isala research team. For example, last year in the summer (when there was no mention of COVID-19, and it was cucumber time), I was interviewed and asked: how often do you have to wash your underpants. I must say that I was often approached by colleagues and friends about this subject. Everyone had an anecdote about young people at camp or friends who changed their underwear far too little 😊 .   

When this year, in full Corona time, the wearing of (homemade) cottonmouth masks were recommended, I immediately made the link with our research on the skin microbiome, the jeans, and the more playful advice about changing underwear. Good hygiene for our underpants is included in everyone’s upbringing. This habit is therefore strongly established, in contrast to the necessary hygiene measures for using mouth masks. Because this is new to most of us and therefore requires a certain awareness. We felt that too little attention was paid to the fact that with every exhalation or with every drop of saliva, you also accumulate all kinds of bacteria, fungi, and viruses on your mouth mask. Moisture and food residues in our saliva can create an ideal environment in which bacteria and fungi can grow. A quick dive into the scientific literature showed that this too had not really been researched. So we decided with our research team to test some things ourselves.  

For example, we have found that cotton masks concentrate 10 to 20 times more bacteria than disposable surgical masks. And while most of the bacteria and fungi on your face mask are harmless, some could potentially make you sick. For example, we found staphylococci that can cause acute and chronic sinusitis and skin infections such as acne. In your nose, mouth, and on your skin, these are usually suppressed by your immune system. However, on a mouth mask, they can grow to higher concentrations.  

Nevertheless, an essential point of attention shows how important it is to handle our mouth mask hygienically. That’s why we tested how to remove those bacteria in the most appropriate way: by washing at 100°C, washing at 60°C with soap, ironing with a steam iron, putting in the freezer overnight, or leaving it on a countertop for three days?

Our results have shown that it is best to wash your face mask at 60°C with soap, cook at 100°C or use a steam iron. And putting on a cleanly washed or fresh one every day is a golden rule, just like our underpants. 😊 

We saw this playful message from the Red Cross last week and were a big fan. And with the new measures in the province of Antwerp in mind, we can also say, “Don’t take it out in busy, public places, that’s inappropriate.” 😉