FFP masks are a multilayered system of fleece materials, with each layer performing special functions. The electrostatically charged fiber mesh can filter particles from the air in the nano- and micrometer range: Particulate matter and saliva aerosols laden with pathogens such as the coronavirus. The outer layers are made of spunbonded fleece, a synthetic polymer melted and spun to produce continuous filaments. In order to maximize the protection, melt-blown fabric is inserted as the inner layer (made from electrostatically charged, melt-blown discontinuous fibers). This super-dense filter can trap even the smallest of particles like a magnet – including individual viruses – provided they are floating in the air without a secretion balloon. In the European Union, FFP masks are tested on the basis of the EN 149 standard with the finest test aerosols, paraffin oil in aerosol form, or sodium chloride. Each manufacturer also uses at least two test subjects to determine whether the mask is sealed when worn correctly. Approval in accordance with N95 and KN95 – the respective US and Chinese standards – tests solely the material.
The more layers a mask has and the thicker the material, the higher its breathing resistance may be. In order to minimize the level of stress caused in the workplace, the German Social Accident Insurance (DGUV) specifies that wearers of an FFP mask without an exhalation valve should take a 30-minute break after 75 minutes. Attention must be paid to the breathing resistance in everyday infection control situations. If in doubt, medical advice should be sought. The same also goes for people with preexisting medical conditions. Dräger research and development laboratories are continuously working on optimizing FFP masks and breathing resistance values without sacrificing filter performance. Particle-filtering half masks are commonly used by tradespeople and in industrial settings to protect against dust or other toxic substances in the air; they have also been used in hospitals and care facilities since the 1990s.
Occupational health and safety laws govern where, when, and how they must be worn. “The current pandemic comes up against certain occupational health and safety standards,” says Denis Beisch, Dräger marketing manager for lightweight respiratory and body protection. “In hospitals, industrial settings, and fire departments, the employees know how to wear an FFP mask. They also know that a beard breaks the seal.” The key is to make sure that the area of the skin where the mask sits is smooth. “A mustache is allowed,” says Beisch. Dräger also offers business customers testing of tight-fitting masks based on the ISO 16975-3 standard. Every employer monitors to make sure that their employees are equipped in line with the relevant laws. One option would be to use breathing protection where no tight seal is necessary – like a hood in combination with a power air-purifying respirator (e.g. Dräger X-plore 8000). The USA and UK also make it mandatory for companies to supply breathing protection adapted to the size and shape of the face for risky activities.
THE POWER OF THE FILTER
Vaccinations and drugs are powerful tools when fighting a pandemic. However, until they are available to everyone, social distancing and hygiene rules help. “People must get away from the idea that there is one measure that cuts the risk of infection to zero,” says Christof Asbach, president of the Association for Aerosol Research. “Even when an FFP2 mask fits perfectly, up to six percent of harmful substances can still get through.” This is the figure specified in the EN 149 European testing standard. Dräger’s own online shop (https://ffpshop.de) also shows how FFP masks can be used most effectively. “The approach is always the same,” says marketing manager Beisch. “As soon as the air escapes around the edges, the fit must be corrected.