Respirators, surgical masks or sewn face masks – the differences in masks and the protection they offer are huge. According to experts, some could even convey a false sense of security.
From Kai Laufen, SWR
There is a lot of discussion these days about face masks to protect against the coronavirus. But not all masks are the same – the differences are big: Respiratory masks are made of hardened paper or fabrics and are multilayered, they have filters and sit a little distance over the mouth and nose, and are close to the cheeks. Only these masks are certified for biological threats such as the SARS-CoV-2 virus, only they protect against both infection and spread of the virus. They are called "Filtering Facepieces", or FFP for short, and they are divided into protection classes. Only respiratory masks with protection class FFP2 or FFP3 are certified for medical personnel in dealing with the coronavirus.
But: High-quality masks of this high protection class have valves that release the breath of the wearer to the outside. If the carrier is infected, viruses would also be released from it. In addition, the protective effect of these masks is not unlimited, so they have to be changed at regular intervals.
Because their safe use is so demanding and, above all, because there is a threat of a shortage of these professional masks, they should only be reserved for medical personnel for the time being.
Mouth and nose protective masks (MNS), also known as surgical masks, are much more common – especially in Asia. They are made of several layers of fabric, one of which has a filter effect and the outer layer must be liquid-repellent. The filter effect occurs when the special material is statically charged by the friction on the two adjacent layers. Both this charge and the liquid-repellent protection would be lost when washing, which is why only disposable products are permitted in the EU. But because both types of masks are currently in short supply, the Robert Koch Institute has on March 13th a multiple use recommended.
Stitched cloth masks provide protection?
Aside from these certified masks, there are also pure fabric masks that citizens sew themselves or that are commissioned by desperate hospitals from German textile manufacturers. There are no scientific statements about their benefits, but there are different assessments: The Berlin virologist Christian Drosten thinks that such masks could possibly help to slow down the spread of the virus. Whoever carries the virus in himself and coughs, then hurls less of it in public. In addition, fabric masks for the general public can help to avoid a lack of professional protective equipment in the medical field.
The businesswoman Ming Gutsche has specialized in the European medical market with her company DACH GmbH in Rastatt since 1996. She partly designs "Personal Protective Clothing" (PPE) herself, which she had manufactured in China until the end. She doesn’t believe in fabric masks without a certificate: "They are completely unsuitable. Such products have absolutely no filtering effect." They are even dangerous, "because whoever puts on such a mask may feel protected, but in fact they do not protect at all. Perhaps they protect against the cold, but definitely not against viruses."
In fact, the EU standards stipulate that the mouth and nose protective mask "consists of a filter layer that is embedded between layers of fabric, firmly connected to them or fitted into them." (EN 14683: 2019 + AC: 2019) Most of the patterns that are now in circulation, but also the product that the Swabian textile company Wolfgang Grupp offers on the homepage of his company Trigema, only show two layers and, above all, do not have a special filter layer.
Trigema also writes this on its own website: "No certification – not medically or otherwise tested." But the company also writes: "In the current Corona crisis, protective clothing is urgently needed. Trigema has therefore switched its production to counteract the shortage of mouthguards with immediate effect.
Experts see the danger that people believe such masks can protect them. Such masks "neither meet the requirements as a medical product nor the industrial safety regulations as personal protective equipment," explains Christian Kuhn. The independent health care expert from Schleswig-Holstein warns against makeshift masks: "In the case of biological hazards and viruses of hazard class 3, which currently includes the coronavirus, at least protection level three masks are to be used because of the filtration performance and the small overall leakage rates. Cloth towels are miles away from this . "
Only statically charged filter layer is effective
The filtration performance of certified MNS masks is the result of the static charge in the middle fabric layer – a property that self-made or simple fabric masks sewn in textile factories cannot have. The "overall leakage rates" mentioned in the standard relate to the penetration of viruses from the side and explain why certified mouth and nose protection can only be the second choice in the corona crisis: only tightly fitting respirators of protection level two and three would be real Giving security, says the expert Kuhn.
Kuhn is also an expert in occupational safety. He is very concerned about the press reports about clinics that are now ordering large numbers of masks from German textile companies – which in his view are unsuitable -: "The focus here is certainly on the idea of actively helping out of an emergency."
Lack of reserves
The current shortage of real protective equipment – be it breathing masks or face-to-face masks – is what Kuhn blames on politics. The federal government and the states had not followed their own pandemic plans and recommendations of the Federal Office for Civil Protection and Disaster Relief. They would not have kept appropriate reserves of personal protective equipment for the facilities of the critical infrastructure – such as clinics and rescue services.
According to Kuhn, the emergency services department of the Association for Safety, Health and Environmental Protection at Work warned the Federal Ministry of Health "at the beginning of February" that personal protective equipment was running out in many emergency services.