Steam can be an effective sterilizer if used properly and within small easily controllable areas such as autoclaves and sterilizers. If used outside of autoclaves however, the process parameters required for sterilization are harder to maintain and its effectiveness rapidly diminishes. The high temperatures and required contact time for steam to be effective become very difficult to maintain outside of controlled chambers making sterilization of larger areas impossible and spot treatments increasingly difficult. Steam cannot be used for the decontamination of temperature sensitive equipment or moisture sensitive materials such as electronics.
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 are limited by temperature and environmental factors which negatively affect their distribution properties.
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 liquids and vapors.
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 through 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.