Oscar García Meza
Sulsba Yépez
The content of this news item has been machine translated and may contain some inaccuracies with respect to the original content published in Spanish.
Since March 2020 we have become familiar with the use of face masks. In order to protect us from the coronavirus, we use them in different types and materials. What we don't know, exactly, is how much they really protect us. Does the KN95 I bought filter the 95% it promises? Does the one I got in fabric with the crest of my favourite football club help keep aerosols out? Does a surgical mask plus a respirator really give me the protection I need? These are some of the questions we ask ourselves.
In our country, there was practically no way to test the filtration efficiency of the masks and thus know if we are protected against the coronavirus. However, recently, our Materials Characterisation Centre (CAM-PUCP) acquired a Dekati model ELPI equipment. This is a real-time particle analyser with a coupled system specifically for the evaluation of masks and respirators. This equipment will be used for the one-year mask quality control subproject, which is being carried out within the framework of the Medical Devices project.
Head of CAM-PUCP and Dean of the Faculty of Science and Engineering
The particulate analyser will be used in various ways. "The National Centre for Quality Control (CNCC) of the National Institute of Health (INS) will commission us to evaluate the masks used in the Peruvian market," says Rumiche. On Thursday 8 July, members of the CNCC visited the CAM-PUCP facilities to inspect the equipment.
The dean of the FCI also mentions that the idea, in the near future, is to help developers, textile entrepreneurs and interested parties in general to evaluate, with a grant from the Technological Institute of Production, the quality and filtration of the masks they offer. "This is a need that the subproject hopes to fill," he adds.
Other applications that the equipment can offer, says Rumiche, is the analysis of air quality, which will be very useful when we return to being on campus. It can also be used to check whether, after undergoing a cleaning process with ultraviolet light, a mask is still filtering efficiently.
This particle analyser will be of great use to all manufacturers and developers who until now have had to send their masks abroad for testing, with the time and high investment that this entailed.
The efficiency of a respirator is determined by its ability to filter out airborne particles. Depending on the level of filtration and the size of particles filtered, it can be said whether this device is optimal or not.
To test the new equipment, Dr Rumiche says that a mannequin - which has nose holes and a connection to a vacuum pump that emulates human breathing - is placed in a chamber with particle aerosol, with a mask on. The equipment analyses, in real time, the number and size of particles passing through the mask. To determine the level of filtration, the initial concentration of particles in the aerosol and the concentration recorded at the end are taken into account.
"Based on this measurement, we can say, for example, whether the KN95 you have purchased really filters that much or whether this or that tissue is really useful," says Rumiche. The acquired equipment is capable of analysing particles in the range of 6 nanometres to 10 microns in a single measurement. Our FCI dean points out that the standards for respirators take as a reference the filtration of airborne aerosols of 0.3 microns because aerosols of this size are able to pass through the microfibre mesh of a respirator, while larger or smaller ones are trapped.
The acquisition of the Dekati ELPI particle analyser has been carried out within the framework of the PUCP Medical Devices project, which is the result of an agreement between our University and the Instituto Tecnológico de la Producción (ITP) of the Ministry of Production, which finances it.
In addition to CAM-PUCP and ITP, the Academic Department of Engineering, the PUCP Materials Laboratory and the Institute of Omic Sciences and Applied Biotechnology (Icoba-PUCP) are participating in this subproject for the quality control of face masks. In the line of evaluation of masks, two more pieces of equipment will also arrive on our campus: one to carry out differential pressure tests and the other to evaluate resistance to blood splashes. This will complement the equipment that can carry out a very complete measurement of the efficiency of masks in accordance with the standards governing these products.
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