Professor Helen Storey is wearing jeans that clean the air around them. She calls them cataylsed jeans. The former fashion designer believes the laundry detergent they were washed in could contribute to a significant improvement of air quality. Working alongside chemistry professor Tony Ryan, Storey's developed Catclo, a detergent additive that sticks to clothes' surface fibres and neutralises airborne nitrogen oxides. Ryan came up with the idea at an academic meeting. SOUNDBITE (English) TONY RYAN, PROFESSOR OF PHYSICAL CHEMISTRY AT SHEFFIELD UNIVERSITY, AND CO-DEVELOPER OF CATCLO, SAYING: "I sat down and calculated the surface area of my suit in this really boring meeting I had to go to and when I came back I had the answer of how we could use low-grade energy. We'd turn people into catalyst supports, so that they were covered in catalyst and could wander around using light and the surface of their clothes to clean up." Catclo contains nanoparticles of titanium a thousand times thinner than a human hair. When clothes are washed in it, the nanoparticles remain within the fabric, so they only have to be washed with the additive once. The by-product - harmless, water-soluble nitrates - wash away when the clothes are laundered. Normal detergent can be used in subsequent washes. SOUNDBITE (English) TONY RYAN, PROFESSOR OF PHYSICAL CHEMISTRY AT SHEFFIELD UNIVERSITY, AND CO-DEVELOPER OF CATCLO, SAYING: "The regular questions are: 'am I absorbing dirt, am I walking around getting dirtier?' and we know from market research that customers don't want to wear self-cleaning clothes because they want to wash them, they want to feel clean. And the answer is no, the pollution's just passing you by, but when it comes into contact with you you neutralise it." When catalysed garments are worn outside, light shines on the titanium particles and excites the electrons on the particle surface. These react with oxygen, encouraging lone oxygen atoms to suck nitric oxide and nitrogen dioxide out of the atmosphere. Helen Storey, who counts Madonna among her former fashion clients, developed a passion for clothing science in the 90s. She regularly wears clothes washed with the additive and says any damage to their quality is undetectable. SOUNDBITE (English) HELEN STOREY, PROFESSOR OF FASHION SCIENCE AT THE LONDON COLLEGE OF FASHION, AND CO-DEVELOPER OF CATCLO, SAYING: "This piece has now been sprayed for about a year and I've been wearing these jeans for about two years and so far there's been no detrimental effect to the process, either of the handle of it or the wear or the colour of it. But a lot of those things are a very natural process of taking it from something like this, which you could call almost installation art to a product that's fit for market." And Catclo could be fit for the market within a year, according to Ryan. The pair won't patent their invention, in its final development stages, hoping all laundry manufacturers will add it to their detergents. They say if they can persuade half the population to wear an item of catalysed clothes at any one time they can make a significant dent in air emissions, and give new meaning to the concept of clean clothes.