In an interview with Adnkronos, Cristina Boi, chemical engineer at the University of Bologna who deals with the testing of masks, summarized what needs to be done and not done to use them better. If you follow these tips, the “mask works well for up to 40 hours,” the expert said. In doubt, other experts advise not to reuse them.

First, said Boi, “you don’t have to put the mask in a plastic bag”. It is better to use paper or fabric, although “the ideal would be to hang them at home in a clean place”.

Even the habit that many have of wearing the FFP2 over a surgical is wrong, emphasizes Boi. The first, in fact, “protects more not for the material but for its greater adherence to the face”. If you want to use two, it is therefore better to do the opposite: use the Ffp2 under and the surgical on top, which allows an extra layer of filtration and protects the Ffp2 from dirt”, explained the expert. ” This is what Americans call the ‘Emmental effect’, referring to cheese holes: if I put several layers together, the holes in different positions create more ‘full’ and retain more particles”.

Some people may find it harder to breathe with FFP2. The advice that the expert gives them is to use it when, when entering a closed place and to replace it with surgical in other cases. The suggestion is “take the two types with you”.

Different rules apply to colds. In another interview with Adnkronos Salute Massimo Andreoni, chief of infectiousness at the Policlinico Tor Vergata in Rome and scientific director of the Italian Society of Infectious and Tropical Diseases, said that “in this case the mask deteriorates more quickly and therefore needs to be changed more often”.

The virologist Fabrizio Pregliasco instead recalled that it is necessary to cover both nose and mouth, and stressed that “homemade inventions such as spraying them with disinfectant and then putting them in the air could damage them making them ineffective. When it is removed, it must always be kept by the rubber bands, to avoid contamination from the outside, in case there was an exposure to the virus”.

Also ban kissing with a mask. “Not a good idea. We could risk ‘smearing’ the virus on the cheek of the victim”, says Pregliasco, remembering that the virus may be present on the outside of the protection device.

The mask, we learn to use it to optimize its effectiveness.