Experienced physicians at QI International LtD reviewed the NK95 FFP2 professional mask documentation as part of a quality control project on their products.
The analysis of the technical documentation and the results of the experimental tests confirm that the mask meets the requirements of EN 149:2001 and A1:2009 as well as the STANDARD GB2626-2006. It falls into the NK95 category and is a disposable mask. It has slightly higher characteristics than en 149-2001 for FFP2 (NK95, filtering efficiency or PFE >= 95%, FFP2 >=94%).
The structure of the mask indicates a high level of technology and quality.
(a) outer layer of support and prefilter, spunbond technique, of 230 consisting of fibers of large diameter (>10 ) homogeneous and confluent on the crossing/melting points of the fibers (visible with a low magnification three-dimensional effect in Figure 2 (38x) and high magnification (250 x) and in polarized light in Figure 3, which also highlights the different optical characteristics of the fiber at stress points.
b) inner layer of additional prefilter, and semifiltered, of thickness “out of all” of about 200-, consisting of high diameter fibers, lasse.
c) two overlapping filtering layers (it should be noted that a single “leaflet” is appreciated for a coarse analysis, but these are two overlapping layers; perfectly matching, however difficult to cleft) of thickness of 85 (170 in total) consisting of a very compact mix of fibers with a micrometric diameter (1-3- well highlighted in the high magnification photo (350x) in polarized light on dic Smith Leitz system that , thanks to the insertion of a lamba filter, allows to form an idea of the structure and orientation of the fiber planes (Figure 4). Note, to better appreciate the complexity of these filtering layers, that the figure highlights and highlights (thanks to the use of redimensional image reconstruction software), only the first 9 microns (out of 170 !) that constitute the “artificial” sharp depth of field obtained in post-production.
d) finally an anallergic inner layer of contact with the skin of the face and leprosy, shown in Figure 5 (high magnification, polarized light at +15°) without significant effects on the filter
It should be pointed out that the comparative analysis of other masks classified as N 95 (nrmativo US) or NK95 (International legislation) have not as well organized structure and layers and, often, with intermediate filter layer with fibers of greater diameter (and proportionally lower filtering capacity) if not in some cases of use of mixed spunbond technique together with melt blown with a mix of coarse fibers (20 microns) interspersed with sometimes laughable amounts of fibers between 1 and 5 microns.
The mask with excellent adherence to the face thanks (suitable for use in adults) thanks to the correct sizing and the sufficient elasticity of the outer edges and the good pull force of the elastic bands, which in some cases may need to be adjusted (even shortening them with a knot).
Explanations on the Table: the table below indicates the types of masks recommended for the various situations. The table derives from considerations that take into account both the related critical issues current pandemic, and the general indications deriving from the recent Emergency Decree that liberalizes the production of masks and drastically reduces the certification obligations.
The table highlights in red cases where quality levels cannot and should not be exceeded; on the contrary, it should be observed that they should always be as high as possible, as the assumption that any facial protection device adopted is useful for protecting against viruses is scientifically incorrect.
Only DPI-facials with high efficiency must be used, because tissues transparent to the virus and flugge droplets, or with limited filtering capabilities can have completely counterproductive effects, as people, feeling protected without being protected, will expose themselves more or expose others to contagion.
Prof. Antonio Vittorino Gaddi, MD, PhD
Research Doctor in Experimental Medicine and Atherosclerosis – Consultant: Cardiology, Geriatrics and Gerontology
Main Investigator of Health Research and Development SrL (spin.out UNIBO) – Scientific Director of Qi International Ltd, London, UK
Past President of the Medicine and Surgery undergraduate course of the Bologna University –
Past Director, Giancarlo Descovich Center of Atherosclerosis and Metabolic Diseases, Bologna University
President of Digital SIT-EMR (Italian Society of Digital Health and Telemedicine, Emilia Romagna Region), Director of Scientific Board of EuroGenLab (BO). Lugo Medica and Caravelli Lab & EuroGenLab, via Acquacalda 3 (Lugo, RA) and via Zamboni 8, Bologna, 051 231531 – Mobile +39 3341953354 – Email: email@example.com
CV: https://www.researchgate.net/profile/Antonio_Gaddi – it.wikipedia.org/wiki/Antonio_Vittorino_Gaddi