Background Air pollution from traffic is a growing problem, especially in urban areas. In recent years the use of titanium dioxide (TiO2) based photocatalytic self-cleaning and de-polluting materials has been considered to remove these pollutants. TiO2 is now commercially available and used in construction material or paints for environmental purposes. Further work, however, is still required to clarify the potential impacts from wider TiO2 use. Specific test conditions are required to provide objective and accurate knowledge. Objectives The aim of the LIFE PHOTOCITYTEX project is to assess the effectiveness of using TiO2-based photocatalytic nanomaterials in building textiles as a way of improving air quality in urban areas. Moreover, information on secondary products formed during the tests will be obtained, yielding a better overall understanding of the whole process and its implications. Specifically, the project aims to: Review the current technologies available and identify photocatalytic compounds that are suitable for use with textiles; Review European legislation related to the concentration of pollutants in urban environments to establish the large-scale demonstration conditions; Develop textile prototypes on a semi-industrial scale in the form of awnings and wall coverings; Demonstrate on a large scale the use of photocatalytic textiles for the depollution of urban environments by employing EUPHORE chambers (half spherical Teflon bag with a confined volume of air of about 200 m3 where representative European atmospheric conditions can be simulated using natural sunlight); Acquire information on secondary products formed during the tests, improving understanding of the whole process and its implications; Install the photocatalytic textiles at two urban locations in Quart de Poblet; and Draw up a guide that establishes a common methodology for the application of photocatalytic textiles in polluted environments. Expected results: Demonstration of the effectiveness of photocatalytic textile in order to reduce the atmospheric concentration of nitrogen oxides (NOx) to a limit lower than 40 mg/m3 established by European law; Concentration of characteristic pollutants in an urban environment or in tunnels (ranging from 0.01 to 10 ppm) is compatible with photocatalytic degradation even with low ultraviolet sun radiation; Reduced concentrations of at least two VOCs from air in the target areas; Normal conditions (e.g. type of radiation) determined for each type of titanium dioxide (TiO2) based textile to be most efficient as a pollution control agent; Identification of urban areas with good potential for improved air quality from addressing traffic related air pollution; Clarification of appropriate procedures and protocols for evaluating the efficiency of the new materials; Confirmation of the policy implication of the use of these new functional textiles in European local, Regional and global scales within Europe; and Cost benefit assessment used to encourage local authorities and stakeholders to replicate the project’s techniques.