21 CFR 211.101 - Charge-in of Components

What it says

Weighing, measuring or subdividing operations for components must be adequately supervised, and where a component is added by an automated system, appropriate controls must verify the correct component is added in the correct amount, with a second person independently verifying weighing and measuring for critical, non-automated operations.

Paraphrased for plain-language clarity. Always verify against the current published regulation text.

What it means in practice

• The second-person verification requirement for manual weighing and measuring exists specifically because this is a point in the process where a single, undetected human error can directly affect every unit in a batch.
• Automated charge-in systems still require verification controls, meaning automation is not treated as inherently more trustworthy than manual weighing without its own confirmatory checks.
• This provision anchors the accuracy of the entire batch formula from the earliest point in manufacturing, meaning an error here can propagate silently through the rest of the process.

What FDA inspectors look for

• Whether second-person verification for manual weighing and measuring is genuinely documented with two distinct, identifiable individuals, not one person signing both roles.
• Whether automated charge-in systems have documented verification controls confirming correct component and correct quantity for each addition.
• Whether weighing and measuring equipment used for charge-in has current, appropriate calibration status.

Related regulations