With the advent of the COVID-19 pandemic, there has been a global incentive for applying environmentally sustainable, and rapid sterilisation methods, such as ultraviolet-C radiation (UVC) and ozonation. Material sterilisation is a requirement for a variety of industries, including food, water treatment, clothing, healthcare, medical equipment, and pharmaceuticals. It becomes inevitable when devices and items like protective equipment are to be reused on/by different persons. This study presents novel findings on the performance of these sterilisation methods using 4 microorganisms (Escherichia coli, Staphylococcus aureus, Candida albicans, Aspergillus fumigatus) and 6 material substrates (stainless steel, polymethyl methacrylate – PMMA, copper, surgical facemask, denim, and a cotton-polyester fabric). The combination of both ozone and UVC generally yields improved performance compared to their respective applications for the range of materials and microorganisms considered. Furthermore, the effectiveness of both UVC and ozone was higher when the fungi utilised were smeared onto the non-absorbent materials, than when 10 µL droplets were placed on the material surfaces. This dependence on the contaminating liquid surface area was not exhibited by the bacteria. This study highlights the necessity of adequate UVC and ozone dosage control as well as their synergistic and multifunctional attributes when sterilising different materials contaminated with a wide range of microorganisms.
- ultraviolet-c radiation
- microbial inactivation
- personal protective equipment (PPE)
- material contamination