Air quality is a problem for a growing number of cities around the world. And so protective masks and the materials they are made from are becoming subjects of design.
In recent years, research into filtering materials to be worn for the protection of human breathing has accelerated sharply, offering increasingly high-performance solutions. But material efficacy alone would not be sufficient to ensure good protection. The design of the mask matters, to guarantee a good response to two key factors: a perfect fit on the face, and full acceptance on the part of those who are supposed to wear it.
The reasons why research in the field of filtering materials is in constant evolution come as no surprise. Air quality indices map in real time the quantity and concentration of pollutants in the world's major cities currently being monitored. Delhi and Beijing, to cite just two of the metropolises where air quality has for years been consistently below the safety threshold, reach daily concentrations of pm2.5 alone in excess of 100 micrograms per cubic metre (where the acceptable value set by the World Health Organization is 10 micrograms per cubic metre, μg), and not infrequently record values exceeding 300–400 μg per cubic metre. Pm2.5, all the more harmful because it is capable of reaching the deepest areas of our respiratory system, is unfortunately not the only pollutant that filter materials attempt to screen out, and the WHO estimates that 4.2 million premature deaths are today attributable to high outdoor exposure to polluting agents of various kinds.
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All anti-pollution masks share the same underlying technology, which works on the principle of overlapping micro-grids to stop and trap the harmful particles that would otherwise enter our bodies through inhalation. A relatively simple technology, born more than a hundred years ago with the introduction of chemistry into the tactics of war — that is, centuries after the onset of urban pollution — as a more efficient solution than the piece of wet bread to hold in the mouth while covering the nose with a handkerchief, which soldiers used as protection against gas. The first filtering materials were sheets of layered cellulose, with an absorbing capacity five times greater than that of traditional cotton fabric, which would pave the way for disposable products. The best known of these materials, Cellucotton, was applied by the Americans to the first gas masks.
Today the issue of protection is no longer a military one: it concerns atmospheric pollution in large urban concentrations and the growing aggressiveness of viral epidemics, as is happening with the coronavirus, which are capable of mutating and evolving with great speed.
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To selectively protect our breathing from external threats, various types of materials are used, all based on the logic of overlapping filtrations: microporous polyurethanes (which owe their ability to trap dust and allergens to their microscopic structure); polymer fibres (from non-woven fabric to be layered — four layers for effective filtration — to nanofibres); or natural fibres (which in the longer term represent the ideal solution for reducing the environmental impact of disposal). Each of these solutions may then incorporate additional layers of silver fibres (antibacterial and sanitising) or activated charcoal powder (absorbent, including of odours), to enhance the effectiveness of the protection. In some cases, exhalation valves are combined with self-filtering materials to improve comfort, particularly during prolonged use, by reducing humidity and heat inside the mask.
Different materials correspond to devices designed for different kinds of filtration, given that there are different degrees of aggressiveness and danger among the pollutants to be blocked: from simple seasonal pollens to the feared particulates, airborne dispersions of microscopic dimensions capable of settling in the deep areas of our respiratory system.
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Based on the filtering power of the materials they are made from, face masks are classified according to precise evaluation standards, established by European regulations for this type of device, which require a full fit to the face. The European FFP, the filtering facepiece, stipulates that the filtering mask must be half-face (leaving the eyes uncovered, fitting snugly over the nose and chin) and defines three classes of protection.
The first, FFP1 with a first-level face filter, certifies masks with a filtration rate corresponding to 78 per cent of particles up to 0.6 microns in size.
FFP2 certifies filtration of up to 95 per cent and FFP3 certifies filtration of up to 99 per cent. The corresponding American standards are N95 and N99. Choosing masks that comply with certified standards is essential to be sure of significantly reducing the intake of invisible airborne particles, such as PM10 and PM2.5, which have average diameters of respectively less than or equal to 2.5 microns, and up to 10 microns.
The current coronavirus pandemic has brought the design and performance materials of anti-pollution masks to the very fore, as well as the companies that have invested in them. In recent weeks the entire world of design and innovation has mobilised, bringing fresh creativity and new minds to bear in order to provide concrete support for the urgent needs of protection and care, above all for healthcare workers. One of the most recent contributions is that of the British firm Foster + Partners, which has designed and made available as an open-source resource a working prototype of a personal protective visor, producible by laser cutting.
We asked Tommaso Puccioni, co-founder alongside Stefano Bossi of Banale, the Italian company of "accessories for travellers" and producer of high-quality anti-pollution masks that in just a few years have won over distant markets such as China, South Korea and Singapore.
"At the heart of a good product is first and foremost a perfect fit, because if the mask does not adhere well to the face the protection is greatly reduced; and, of course, efficient filters. On this front we chose not to limit ourselves to customising an existing filter: we looked for a high-level technological partner who could work alongside us in developing our own product, designed from scratch – explained Puccioni –. In Europe alone there are around twenty companies producing filtering materials, normally used for domestic or industrial technologies. We set out to identify an Italian partner willing to make a research investment in our product. And we found it in Bls, a Milan-area company specialising in personal protective equipment for industrial use. Today our Mask and Active models compete well in the Asian premium market thanks to the combination of technology and Italian design, which we have focused on from the very beginning: effective filtration and the best possible fit, but also aesthetics. The user experience is fundamental in this sector. And design serves to guarantee a quality user experience from an aesthetic standpoint as well."
Recent data show that the global market for filtering masks had already exceeded two and a half billion dollars in 2018. But while it is true that deteriorating air quality has broadened the use of these protective devices, and that in some cities they are mandated at particular moments of smog-related environmental emergency, getting people to accept them is not straightforward.
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Function and aesthetics, technology and cultural attitudes, go hand in hand in protecting our breathing from pollution. The Japanese and Asians in general, for example, are accustomed to wearing surgical masks to prevent allergic reactions or the spread of illnesses such as colds and flu, but the real step change came with the new generation of masks, presented as designer urban accessories.
Even before technical efficiency, the real prospect for these protective shields — "facewear", as some have called them — of becoming a good habit depends on design's ability to turn them into consumer objects, attractive and appealing. Today ultra-high-performance designer masks are beginning to become available, well made and effective, as in the case of the products from Italy's Banale, at a relatively affordable cost that varies depending on whether they are single-use, or washable, long-lasting items with replacement filters.
The Japanese Pitta is a mask that protects against 99 per cent of pollens, which in Japan are the main reason for purchasing a respiratory protection mask. It is based on the use of an innovative, proprietary material: a microporous polyurethane with a 3D structure of microscopic open pores, which traps pollen particles and adapts perfectly to the shape of the face, ensuring high-performance filtration. The material itself, available in elegant, on-trend colours, is the mask: single-layer and with a perfect fit, achieved simply by pressing by hand over the area to be moulded. The mask can also be hand-washed, allowing for reuse.
There are also those who, like the Polish company Lekko, offer a smog-protection scarf. Fitted with four small holes aligned with the two exhalation valves of the underlying filter mask, the scarf is made from a cotton fabric padded on the outside and micro-mesh fabric, and features on the inside an interchangeable three-layer nanofibre filter system and an activated carbon layer. The two exhalation valves, in plastic material, are finally reusable when the filters in the inner mask are replaced.
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