Most of us spend at least 30% of our time at work, often inside the same building from 8am to 5pm, with maybe an hour’s break to step outside. It’s important therefore that the buildings where we work should be ‘healthy’ buildings. The World Health Organisation (WHO) has recognised Sick Building Syndrome (SBS) for almost three decades. In 1984 the WHO reported that 30% of new and remodelled buildings worldwide might be linked to symptoms of SBS. The causes are many and varied but SBS is commonly attributed to poor indoor air quality – a result of poor ventilation, faulty or badly maintained air-conditioning systems, a range of indoor chemical pollutants such as small quantities of toxins in the emissions from building and office materials and biological agents such as moulds and bacteria.