For those environmental areas that are either inaccessible for wet sanitation or for dry environments, fogging of biocides is a good measure to help control environmental microbes. A functional definition of fogging is the aerosolization or particles where over 80 percent are under 20 micrometers in diameter. This creates a dry mist that dries almost instantly. Prior to fogging, dry vacuuming or use of dusting attachments must first be undertaken to remove as much dust and soil as is physically possible prior to fogging. Fogging of any type of biocides should be done where the room can be confined or is feasible from a cubic meter/footage standpoint. In essence if the room’s ceiling height is 20 feet high and the room is the size of a football field, foggers cannot handle the cubic area. Fogging mandates very strict safety protocols insuring personnel are not in the room being fogged, requiring automated timing devices and a time period of 60 minutes to two hours prior to reentry into a fogged room. The application of fogged biocides includes coolers and HVAC units or cooling units in a cooling or freezer spiral. Fogged biocides penetrate deep into a HVAC unit and sanitize those environs in a HVAC system that are inaccessible for wet sanitation. Again, QAC/liquid PAA sanitizers can be effective if vegetative microbes are the primary contaminants, while activated chlorine dioxide is preferred if sporeformers, like fungi or bacilli, are an environmental contaminant issue. If the sanitizer applied in the fogging mode is above the approved food contact level then either all food contact surfaces must be draped with plastic or rinsed thoroughly post fogging. However, sometimes an approved food contact level of a fogged biocide like chlorine dioxide is sufficient, which eliminates the draping or rinsing of contact surfaces. Similar provisions need to be applied in an organic plant which requires sanitizers approved as food contact sanitizers like certified liquid PAA or chlorine dioxide sanitizers available on the market.
Giambrone is the vice president of technical services for Rochester Midland Corp.’s Food Safety division. He can be reached at cgiambrone@RochesterMidland.com.
References Furnished Upon Request