Bacterial Viral Filters that provide an efficient hygiene solution, giving better than 99.999% cross-contamination efficiency, protecting the patient, operator and equipment from cross-infection and contamination during pulmonary function testing. Suitable for inspiratory and expiratory spirometry testing. Features an electrostatically charged barrier that filters droplets, aerosols, bacteria and viruses out of the airstream. For each new BVF used on every patient, the interior of the device is protected, meaning that only exterior surface cleaning should be required.