Nasal sprays are widely used for managing respiratory symptoms like allergies, congestion, and sinus issues, often containing decongestants, steroids, or saline solutions. These multi-dose containers are used repeatedly over days or weeks, which introduces a risk of microbial contamination. This risk is amplified when the user has an active respiratory infection like COVID-19, raising questions about re-using the same bottle later or sharing it.
How Viral Contamination Occurs in Nasal Sprays
The primary risk for contamination in a nasal spray used during an infection is “backwash” or “aerosol splash-back.” When the medicine is sprayed and the user inhales, mucosal secretions containing the respiratory virus (SARS-CoV-2) can be drawn back onto the nozzle tip or into the reservoir.
The virus can survive on the plastic surfaces of the nozzle or potentially become suspended in the liquid inside the bottle. Research indicates that SARS-CoV-2 can remain viable on plastic surfaces for up to 72 hours. Even if the liquid contains preservatives, the nozzle’s exterior is consistently exposed to viral particles during use.
Viral shedding is high in the nasal passages, which are a major point of entry for respiratory viruses. The risk of transferring these particles from the infected mucosal lining to the container is significant during active illness. Any contamination that occurs during use is redelivered directly to the nasal lining upon the next application.
Standard Hygiene Rules for Multi-Dose Nasal Sprays
Nasal sprays carry standard contamination risks that necessitate regular discarding. A primary rule of hygiene is that nasal sprays should never be shared with another person, as sharing increases the risk of spreading any pathogen from one person’s nasal passage to another.
Most manufacturers provide a specific “beyond-use” date after the first opening, often ranging between 30 and 90 days. This date differs from the printed expiration date on an unopened bottle and is usually found in the package insert. This shortened timeframe limits the risk of microbial growth that occurs once the bottle is exposed to air and human contact.
Secondary contamination from bacteria or fungi is a concern, especially in sprays lacking robust preservatives, such as simple saline solutions. Even with preservatives, their efficacy can degrade over time after the seal is broken. Using a spray past its recommended discard date risks introducing harmful microbes into the nasal passages.
Making the Decision: When to Discard or Keep
The decision to discard a nasal spray after a COVID-19 infection depends on when the product was used relative to the illness. If the nasal spray was actively used during the period of symptomatic COVID-19 infection, the recommendation is to discard the bottle immediately. This action eliminates the risk of reintroducing viral particles that may have contaminated the nozzle or the liquid reservoir through backwash.
If the nasal spray was not used during the active phase of the illness, it is safe to continue using it, provided it meets standard hygiene criteria. This means checking the manufacturer’s recommended discard date after initial opening, which is typically 30 to 90 days. If the bottle is nearing or has passed this date, it should be discarded for general hygiene reasons, regardless of the COVID-19 illness.
For inexpensive, over-the-counter products like decongestants or basic saline sprays, replacement cost is low. Discarding the spray used during illness provides peace of mind and is a simple protective measure, even if the risk is theoretical. For prescription or more costly sprays used during the infection, a discussion with a pharmacist or healthcare provider is warranted, though replacement is often recommended to avoid potential re-exposure.