Cleaning 



Cleaning is the most important step in the disinfection process. The cleaning process 

 can be broken down into four basic steps: dry clean, wet wash, rinse, and dry. 



1. Dry clean the area to be disinfected with a shovel and broom, an industrial 

 vacuum cleaner, or high-pressure air. This process should begin with the ceiling 

 and continue down the walls with special attention to any overhead pipes, ducts, 

 and lights as well as window sills and molding. Suitable personal protective 

 equipment should be worn if significant dust is raised in the process. WTien this 

 step is finished, there will be no loose dirt, dust, feed, bedding, manure, hay, straw, 

 or any other organic material left on surfaces. The surfaces will not necessarily be 

 visibly clean when this step is complete. 



2. Wet wash all of the surfaces with a soap solution or detergent. During this part 

 of the process, it will be necessary to scrub the surfaces vigorously to break 

 down any biofilm that may be present. The scrubbing can be done with rags on 

 smooth surfaces, although the commercially available plastic or metal scrub pads 

 are much more efficient. Rough surfaces should be scrubbed with a stiff brush 



to ensure that they are cleaned as completely as possible. Deep cracks, crevices, 

 pits, pores, or other surface irregularities should be given particular attention 

 to dislodge accumulated grime. Special care should be taken around electrical 

 equipment. Bring in adequate lighting and turn off electrical power if there is 

 danger of getting cleaning solutions into fixtures. Remove thermostats, timing 

 devices, motor controls, and remote sensing equipment before wet washing. When 

 this step is adequately completed, the surfaces will be visibly clean. The moisture 

 on surfaces will spread evenly, wetting the surface completely. There will be no 

 beading of moisture, which would indicate the presence of oil or grease. 



3. Rinse the surface to remove all traces of soap or detergent. A residue of soap or 

 detergent should not be left on the surface because it may react unfavorably with 

 the disinfectant. When this step is complete, the water film will "wet" the surfaces 

 and there will be no beading. 



4. Dry the area to remove all moisture. Removing the moisture promptly will protect 

 equipment and surfaces from deterioration. Excess moisture will also dilute 



the disinfectant to be applied to the surfaces, and there is no practical way to 

 compensate for the dilution when mixing the disinfectant. 



7-3 



