Dupont reports testing at a veterinary hospital in the USA that showed a near total reduction in the number of environmental bacteria after misting of surfaces in large-animal facilities with a 4% dilution of disinfectant Virkon S. Bacterial colony-forming units were reduced by the equivalent of 6 on a log scale. Typically, a reduction factor of 3-5 logs is considered the minimum for effective disinfection. Results were rated as similar to those achieved by applying a formaldehyde aerosol and better than when aerosolisation was by a glutaraldehyde and quaternary ammonium compound mixture.
