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SOP for Cleaning of Carton Weighing Balance

Last reviewed 29 Oct 2026 · 3 min read

Contents
  1. 1. Objective
  2. 2. Scope
  3. 3. Responsibility
  4. 4. Procedure
  5. 4.1 Health, safety and environment
  6. 4.2 Product-to-product and batch-to-batch cleaning
  7. 4.3 Clean-hold times (example in-house criterion)
  8. 4.4 Records
  9. 4.5 Balance accuracy
  10. 5. Training
  11. 6. Distribution
  12. 7. Annexures
  13. Frequently asked questions
  14. References

In short: This example SOP explains how packaging staff clean a carton weighing balance between products and batches so that no packing material or residue is carried over. It uses dry, lint-free cleaning, status labels and a usage and cleaning log. Adapt hold times and labels to your own quality system.

This is an illustrative template. Cleaning methods, hold times and label formats are example in-house criteria and must be defined in your own approved procedures.

1. Objective

To describe the procedure for cleaning the carton weighing balance and removing residue and packing material of the previous product or batch.

2. Scope

This SOP applies to cleaning of the carton weighing balance in the packaging area of the manufacturing facility.

3. Responsibility

  • Packaging officer/executive: cleans the balance as per this SOP and records the activity.
  • Head of Packaging: ensures effective implementation of the procedure.
  • Quality Assurance: verifies line clearance and reviews the logs.

4. Procedure

4.1 Health, safety and environment

  1. Switch “OFF” the electricity supply before starting cleaning.
  2. Do not use corrosive agents on the balance. Do not spray liquids on the indicator, load cell or cable connections.

4.2 Product-to-product and batch-to-batch cleaning

  1. Switch “OFF” the mains of the carton weighing balance.
  2. Remove the “IN USE” status label and affix a “TO BE CLEANED” label.
  3. Make sure no packing material, cartons or leaflets of the previous product or batch remain on or around the balance. This forms part of line clearance, which must confirm that equipment and work area are free of previous materials before a new operation starts (EU GMP Part I, Chapter 5, §5.50).
  4. Clean the platform, indicator, balance stand and cable with a dry, clean, lint-free duster.
  5. Clean the floor area below and around the balance with a dry, clean, lint-free duster.
  6. Clean the area below the platform with a dry, clean, lint-free duster.
  7. Remove the “TO BE CLEANED” label and affix a “CLEANED” label filled in with: equipment code, previous product, SOP number, cleaned by (signature), date and “cleaned valid up to” date.
  8. Record the cleaning in the area and equipment usage and cleaning log.

4.3 Clean-hold times (example in-house criterion)

  • If the cleaned balance is not used within 48 hours, or visible dust has settled on the outer surface, wipe it with a damp lint-free duster followed by a dry lint-free duster.
  • If it is not used within 72 hours of cleaning, clean it again before use.

4.4 Records

Equipment must be cleaned and maintained at appropriate intervals, and a log of cleaning and use kept (21 CFR 211.67 and 211.182). Keep these logs for at least 1 year after the expiry date of the respective product batch (EU GMP Part I, Chapter 4, §4.11; 21 CFR 211.180(a)), longer if local law or the marketing authorisation requires.

4.5 Balance accuracy

Cleaning does not replace calibration. The carton balance must also be calibrated and checked at defined intervals against written procedures (21 CFR 211.68; 21 CFR 211.160(b)(4)).

5. Training

  • Trainer: Head of Packaging
  • Trainees: Packaging department staff

6. Distribution

  • Controlled copy 1: Head of Department, Quality Assurance
  • Controlled copy 2: Head of Department, Packaging
  • Master copy: Head, Quality Assurance

7. Annexures

Nil

Frequently asked questions

Why use dry cleaning on a weighing balance? Water and cleaning liquids can damage the load cell and electronics. Dry, lint-free wiping removes dust and fragments without that risk.

Does cleaning the balance mean it is also checked? No. Cleaning removes residue; calibration and routine accuracy checks are separate activities with their own records.

How long can a cleaned balance stay unused? The limit is set by your own quality system. In this example, re-cleaning is needed after 72 hours.

See also: SOP for calibration and SOP for equipment cleaning in the production department.

References

  1. European Commission, EudraLex Volume 4, EU GMP Part I, Chapter 5 “Production” (in operation 1 March 2015), §5.13, §5.21 and §5.50.
  2. European Commission, EudraLex Volume 4, EU GMP Part I, Chapter 4 “Documentation”, §4.11.
  3. US FDA, 21 CFR 211.67, 211.68, 211.160(b)(4), 211.180(a) and 211.182.

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