Infectious　microbes　can　spread　rapidly　from　fomites　(contaminated　surfaces)　via　hand　touch,　with　prolonged　residence　time　on　surfaces　increasing　transmission　risk　by　extending　exposure　periods　and/or　involving　more　susceptible　individuals.　Existing　studies　have　focused　on　decreasing　microbial　contamination,　but　not　on　the　need　for　rapid　removal　from　surface　systems.　This　study　introduces　residence　time　as　the　time　that　a　microbe　spends　within　the　surface　system.　We　analyse　both　simple　and　generalised　surface-touch　networks　using　a　compartmental　model,　predicting　the　spread　and　removal　of　infectious　particles　on　surfaces.　Our　models　reveal　the　physics　of　particle　spread　through　four　simple　networks,　yielding　a　closed-form　analytical　solution　validated　by　laboratory　data　on　a　three-surface-touch　network　and　Monte-Carlo　Lagrangian　simulations　of　a　realistic　network.　Findings　indicate　that　hands　and　surfaces,　even　without　any　particle　source,　can　be　highly　contaminated.　Transfer　rates　and　removal　rates　are　identified　as　the　only　influential　parameters　for　equilibration　time　and　the　main　influential　parameters　for　residence　time　in　a　homogeneous　network.　Our　theoretical　model　provides　a　solid　foundation　for　investigating　the　fundamental　physical　process　behind　the　transmission　of　infectious　particles　via　the　fomite　route,　contributing　valuable　insights　for　enhancing　hygiene　management　in　high-risk　environments.