Building Pandemic Resilience Through Chemical Vapour Air Sanitizers

When the next pandemic arrives, the built environment will again determine the trajectory of infection spread. Modern cities are networks of enclosed airspaces—subways, classrooms, care homes, offices—where pathogens thrive. During COVID-19, ventilation and HEPA filtration became the default tools, yet both face structural and economic limitations. Retrofitting buildings for optimal airflow is expensive and disruptive, while filters passively capture particles but rarely inactivate pathogens.

What is needed is an active, continuous, and scalable method of air sanitization. Chemical vapour air sanitizers—systems that release low-level antimicrobial vapours into indoor environments—represent a promising frontier.

The Science

Research over the past two decades has shown that certain vapour-phase antimicrobials can neutralize airborne viruses, bacteria, and fungi without rendering spaces uninhabitable. Examples include:

• Hydrogen peroxide vapour (HPV): Already used in terminal sterilization of hospital rooms, studies show that at carefully controlled concentrations (typically ≤ 1 ppm for continuous exposure), HPV disrupts viral envelopes and bacterial membranes, reducing viable airborne pathogens.
• Ozone (O₃): A powerful oxidant, effective against viruses and spores, though only in strictly regulated, low-concentration ranges to avoid respiratory irritation.
• Essential oil–derived vapours (e.g., thymol, eucalyptol, tea tree oil derivatives): Laboratory studies indicate activity against enveloped viruses and biofilm-forming bacteria. These compounds are particularly promising for continuous low-dose release in occupied spaces due to lower toxicity profiles.

Unlike mechanical filtration, which removes particulates, chemical vapour sanitization inactivates pathogens at the molecular level, reducing the infectious potential of aerosols and surfaces alike. Early modeling suggests a layered system—ventilation plus vapour-phase antimicrobials—could cut effective airborne viral loads by orders of magnitude, decreasing the basic reproduction number (R₀) during outbreaks.

Policy Implications

Despite its potential, vapour-phase sanitization remains underutilized. The absence of clear regulatory frameworks, exposure thresholds, and indoor air quality standards or continuous use is the primary barrier. Governments and health agencies should act now, before the next crisis, to:

1. Establish Safety Standards: Regulatory bodies must define permissible exposure limits for common vapour agents, supported by toxicological and occupational health data.
2. Fund Efficacy Research: Controlled field trials in schools, hospitals, and transport systems should evaluate real-world reductions in pathogen transmission.
3. Incorporate into Building Codes: Air sanitization systems should be considered part of baseline infection control infrastructure, much like sprinkler systems are for fire prevention.
4. Enable Rapid Deployment: Pandemic preparedness plans should include stockpiling and scalable deployment strategies for vapour sanitizer units.

A Proactive Future

The pandemic taught us that waiting until after transmission spirals is too late. By embedding chemical vapour air sanitization into our built environment, we create adaptive spaces that reduce risk in both pandemics and seasonal outbreaks. This is not a replacement for vaccines, masks, or ventilation—it is a complementary layer of defense.

The air we share is both a vulnerability and an opportunity. Science has shown that it can be safeguarded with continuous antimicrobial vapours. Policy must now catch up, turning this technology from an experimental tool into a standard pillar of public health infrastructure.

Peer reviewed studies

Inactivation of airborne SARS-CoV-2 by thyme volatile oil vapor phase

In vitro antiviral activities of thymol and Limonin against influenza a viruses and SARS-CoV-2