A slicer is used continuously to slice deli meats throughout a busy lunch. How often must its food-contact surfaces be cleaned and sanitized during that continuous use?

解析

Food-contact surfaces of equipment used with TCS food in continuous operation must be cleaned and sanitized at least every 4 hours, because pathogens multiply on the soil left on the blade well before that. Stretching the interval to 12 hours or to the end of the shift gives them the whole service to grow, and waiting for visible soil is later still: a slicer is unsafe long before the residue can be seen. Cleaning is also required after each use, when switching between raw and ready-to-eat food, and after any interruption.