Fogging is among one of the most affordable methods for disinfection and sterilization, but its low cost comes at a price as there are many drawbacks to its overall effectiveness. When dispersing your liquid agent as a fog, many factors limit the ability of this agent to reach all the required areas for the required amount of time in order to achieve a successful decontamination cycle. The small droplets created when fogging will be affected by gravity and will make it difficult for the agent to reach areas such as the underside of equipment and components, ceilings, inside ventilation grills and inside intricate equipment.
The Principles of Effective Decontamination are the underlying fundamentals which must be achieved in order to ensure a successful decontamination cycle and apply to all decontaminating agents. Each agent's chemical and physical properties will affect the extent to which these principles are met and will influence the overall effectiveness of the decontamination cycle. Environmental factors will influence these properties and will play an important role in the effectiveness of your agent.
In order for any sterilant to be successful, it must reach all surfaces. True gases such as chlorine dioxide gas, formaldehyde, and ethylene oxide offer the best distribution properties. Liquids and vapors, such as hydrogen peroxide, are limited by temperature and environmental factors which negatively affect their distribution properties and effectiveness.
In addition to complete distribution, the sterilant must be able to penetrate into all areas. As explained above, gases have superior penetration abilities as compared to liquid and vapor agents.
Once your sterilizing agent has distributed to and thoroughly penetrated into all areas, it must remain there long enough to provide the desired level of kill. If it is difficult to get distribution and penetration throughout your target areas as it is for liquids and vapors, then it will also be a challenge to achieve the appropriate concentration and contact time required.