FOOD SAFETY INFORMATION UV lotion typically is used to help visualise difficult- to-clean areas of the hand following handwashing. The lotion is applied to and thoroughly rubbed all over the hands, which are then washed and dried using a prescribed handwashing method. The hands are then viewed under a UV lamp, which reveals any ‘contamination’ remaining on them to demonstrate areas where the ‘contamination’ is particularly difficult to remove or has been missed by the handwashing. Vikan have applied the principles of this test to investigate the hygienic design of food industry drainage systems and cleaning brushware [7][8] . Figures 2a and 2b show a traditional drilled and stapled brush that has been ‘contaminated’ using a UV-sensitive lotion and decontaminated by vigorous dunking in warm, soapy water. Figure 2a clearly shows UV lotion trapped between the brush block and the bristles in the drilled holes. Figure 2b shows a cross- section of one of the drilled holes that reveals residual UV lotion lining the hole within the brush block. Alternative methods of fixing bristles using resin have been employed as a way of eliminating or sealing drilled holes, but even these have hygienic design issues. Figure 3. Image of a UV lotion ‘contaminated’ resin set bristle bundle after cleaning. National Health Service to validate the decontamination of surgical equipment by industrial dishwashers. The dry powder soil is reconstituted using a set volume of water to form a thick solution that is applied to the object under investigation. The ‘contaminated‘ object was then allowed to dry for a period of 2 hours at room temperature before being placed into an industrial dishwasher and cleaned. Cleaning validation is assessed visually through observation of any remaining soil. Figure 4 shows how the red soil has penetrated between the bristles where the resin fails to seal between them, thus creating a narrow channel that has not been possible to clean during the dishwashing process. Figure 2a. Drilled and stapled brush after cleaning. UV lotion trapped between the brush block and the bristles. Figure 2b. Vertical cross-section of a drilled hole containing residual UV lotion after brush cleaning. Figure 3 shows a resin set brush following investigation using UV lotion. Residual‚ contamination can clearly be seen trapped within the loop formed by the brush bristles. Drilled and stapled resin set brushware were investigated using a commercial washer disinfector soil. This red, protein-based soil is used by the United Kingdom Figure 4. ‘Contamination’ (red) trapped between the bristles of a drilled and stapled resin set brush following decontamination using an industrial dishwasher. Channel depth is approximately 8 mm. Copyright © Vikan A/S - Department of Research & Development First published, 2015. Revised, 2023 04
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