Modern hygienic concerns have given air filters a new and expanded role in hospital applications. The purpose of today's hospital air filtration is to provide patients, staff, and visitors with a high degree of protection form airborne micro-organisms, toxic and non-toxic fumes and odors. It should be noted that filtration alone cannot provide a guarantee that infectious, allergenic or irritating particulate matter will be controlled in a hospital. However, in this age of escalating health care costs and tightening budgets, the use and maintenance of high quality filters should be actively pursued because of their potential to provide significant, long-term cost reductions and improved health care.