The importance of environmental contamination in the spread of HAI has generated a need for high performance disinfectants. Currently chlorine based disinfectants are the products of choice, a position reflected in UK guidance. The aim of this research was to evaluate a peracetic acid (PAA) generating disinfectant to determine if it provided a realistic alternative to commonly used chlorine based disinfectants. The European standards framework was employed in this study and enhanced where appropriate by reducing the contact times, increasing the organic and microbial challenge, and changing the organisms involved. When tested against bacteria and spores PAA provided similar or better performance than currently employed levels of chlorine. This was particularly the case in the presence of an organic challenge or dried surface contamination. The chlorine disinfectants only demonstrated superior performance in the case of fungal spores. These results suggest that PAA generating products provide an effective alternative to chlorine based products up to 10,000 ppm free available chlorine. These products have superior performance in situations with spore borne, surface contamination and high organic challenge. In cases where filamentous fungi are a concern, high levels of PAA (>5000 ppm) would be required to match the performance of chlorine based disinfectants.