When applying visual inspection to determine cleanliness of equipment, manufacturers should establish the threshold at which the product is readily visible as a residue. This should also take into ac the ability to visually inspect the equipment, for example, under the lighting conditions and distances observed in the field.
Visual inspection should include all product contact surfaces where contamination may be held, including those that require dismantling of equipment to gain access for inspection and/or by use of tools (for example mirror, light source, boroscope) to access areas not otherwise visible. Non-product contact surfaces that may retain product that could be dislodged or transferred into future batches should be included in the visual inspection.
Written instructions specifying all areas requiring visual inspection should be in place and records should clearly that all inspections are completed.
Operators performing visual inspection require specific training in the process including periodic eye sight testing. Their competency should be proven through a practical assessment.
