Glossary
Mix-up
An incident in which components, containers, labelling, or products are interchanged or intermingled and used in error, to be prevented, alongside contamination, by facility design, segregation, and control.
Details
A mix-up is the interchange or intermingling of different components, containers, closures, labelling, in-process materials, or products: where cross-contamination is another substance getting into the product, a mix-up is the item itself being the wrong one. 21 CFR 211.42(b) requires buildings to have adequate space and flow to prevent this, (c) requires separate defined areas or another control system to prevent contamination or mix-ups in each of ten named operations from receipt, quarantine, and storage through manufacturing, packaging, labelling, and testing, and 211.125(e) requires returned labelling to be identified and stored so that mix-ups are prevented; EU GMP Chapter 5 §5.9 allows different products to be worked on in the same room simultaneously or consecutively only where there is no risk of mix-up or cross-contamination, and §5.46 requires cut labels and other loose printed materials to be stored and transported in separate closed containers. Inspections cite quarantined, rejected, and released materials standing together with no separation, the next product started without line clearance, similar looking labelling stored side by side, and temporary storage areas with no status marking.
Related sections
Related terms
Real inspection findings
Findings from regulators' inspection documents in which this term appears.
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You failed to implement adequate controls to prevent mix-ups, and to assure that all materials not suitable for subsequent operations have been removed.
FDA · FDA Warning Letter · 2023-09-12 -
Your firm also failed to perform operations within specifically defined areas of adequate size and to have separate or defined areas or such other control systems necessary to prevent contamination or mix-ups in aseptic processing…
FDA · FDA Warning Letter · 2025-11-04 -
Your firm also failed to have buildings used in the manufacture, processing, packing, or holding of drug products with adequate space for the orderly placement of equipment and materials to prevent mix-ups and contamination (21 CFR 211.166(a) and 21 CFR 211.42(b)).
FDA · FDA Warning Letter · 2025-07-22
