Background SARS-CoV-2, the virus that causes COVID-19, is an enveloped virus, meaning that its genetic material is packed inside an outer layer (envelope) of proteins and lipids. The envelope contains structures (spike proteins) for attaching to human cells during infection. The envelope for SARS-CoV-2, as with other enveloped respiratory viruses, is labile and can degrade quickly upon contact with surfactants contained in cleaning agents and under environmental conditions. The risk of fomite-mediated transmission is dependent on: The infection prevalence rate in the community The amount of virus infected people expel (which can be substantially reduced by wearing masks) The deposition of expelled virus particles onto surfaces (fomites), which is affected by air flow and ventilation