The Cambridge Mask uses military grade filtration technology to filter out nearly 100% of particulate pollution, gases, as well as bacteria and viruses in a fashion friendly mask suitable for the whole family. This is the British Pollution Solution. Independently Tested The filters used in Cambridge Mask meet the N99 standard (higher than N95). This is a US Government specification for pollution masks. Cambridge Masks have been independently tested by Nelson Labs, USA which confirmed almost 100% of particulate pollution, bacteria and viruses were removed when tested. We have also tested to meet the standards for Chinese NK-95 and Korean Food and Drug Administration requirements. The masks use a triple-layer filter system which will protect from a range of airborne contaminants. What does the Cambridge Mask filter? Almost 100% of Particulate Matter (PM) including PM10, PM2.5 and PM0.3. These are the sort of particles you find in coal dust from power stations, diesel exhaust fumes, factory emissions and from construction works. Almost 100% of gas based air pollution, including odours such as Volatile Organic Compounds (VOCs), Ozone, Benzathine, and Formaldehyde. These particulates you can find in petrol fumes, chemical emissions and from many industrial processes. Almost 100% of harmful pathogens such as viruses and bacteria. Other airborne irritants or allergens such as Dust, mould spores, some odours, pet allergens and pollen. Who is the Cambridge Mask for? Anyone exposed to urban environments with high air pollution levels. People in at risk groups for respiratory disease, including children, elderly, pregnant women and those with existing respiratory conditions. Asthmatics and allergy sufferers including Hay Fever. Hobbyists and DIY such as woodworking and sanding. Anyone travelling to regions known for poor air quality such as China and India. Anyone seeking protection for airborne irritants such as Dust and mould.