How Long Does the Flu Stay on Inanimate Objects
Influenza virus remains infectious on hard, nonporous surfaces like stainless steel and plastic for 24-48 hours, but survives for much shorter periods (less than 8-12 hours) on porous materials like cloth, paper, and tissues. 1, 2
Surface-Specific Survival Times
The survival of influenza virus varies dramatically based on the type of surface:
Hard, Nonporous Surfaces (Longest Survival)
- Stainless steel and plastic surfaces: 24-48 hours of infectious virus survival 1, 2
- Wooden surfaces: Up to 48 hours for pandemic H1N1 strain 3
- Counter tops: Remain infectious for ≥6 hours 1
- Laminated plastic: Similar persistence to stainless steel 4
Porous/Soft Surfaces (Shorter Survival)
- Cloth surfaces: 8 hours of infectious virus 3
- Hospital gowns and paper tissues: 20-30 minutes 1
- Facial tissues: Less than 8-12 hours 2
- Laboratory coats: Up to 4 hours 4
Human Skin
- Hands/skin: Up to 20 minutes after contamination 1
- Virus transfer from surfaces to hands: Measurable quantities transfer from stainless steel for up to 24 hours and from tissues for up to 15 minutes 2
- Virus survival on hands after transfer: Up to 5 minutes 2
Critical Distinction: Viral Genome vs. Infectious Virus
An important caveat: While viral genetic material (RNA) can be detected on most surfaces for 24 hours or longer with minimal degradation, this does not mean the virus remains infectious. 5 Research shows that:
- Viral genome detection: Persists on most surfaces for 24+ hours with little drop in copy number 5
- Viable, infectious virus: Drops much more rapidly, with live virus recovered from most surfaces only 4 hours after application, from some nonporous materials after 9 hours, and below detection level on all surfaces by 24 hours 5
Environmental Factors Affecting Survival
Survival times are influenced by:
- Temperature and humidity: Inactivation increases with higher temperatures (55-65°C) and higher relative humidity (50-75%) 6
- Absolute humidity: A better predictor of surface inactivation than relative humidity alone 6
- Initial viral load: Higher concentrations in the inoculum enhance virus recovery over time 4
Practical Implications for Infection Control
Hand hygiene is paramount because healthcare workers can acquire RSV and influenza by touching contaminated surfaces or inanimate objects in patients' rooms, then inoculating their own oral or conjunctival mucosa. 1
Recommended Decontamination Practices
- Frequent hand washing: Proven to reduce viral spread in healthcare settings 1
- Alcohol-based hand rubs: Preferred when hands are not visibly soiled, as they remove organisms more effectively and require less time than soap and water 1
- Environmental surface cleaning: Use EPA-registered detergent-based cleaners or disinfectants on frequently touched surfaces (tables, door knobs, toys, desks, computer keyboards) 1
- Timing of cleaning: Most critical during the first 24-48 hours after contamination on hard surfaces 3, 2
Hierarchy of Transmission Risk
Under conditions of heavy environmental contamination, transmission via fomites is possible for:
- 2-8 hours via stainless steel surfaces 2
- A few minutes via paper tissues 2
- Up to 24 hours if surfaces are repeatedly re-contaminated 5
The practical takeaway: While fomite transmission is possible, it is unlikely to occur for long periods after initial surface contamination unless re-inoculation occurs. 5 This suggests that in multi-surface environments like homes and hospitals, prioritizing decontamination of hard, nonporous, frequently-touched surfaces within the first 24-48 hours offers the greatest impact on reducing transmission. 3, 5