QC Laboratory Glassware Cleaning SOP

In short: This is an illustrative SOP template for cleaning reusable QC laboratory glassware. Adapt the cleaning agent, rinse-water quality, drying method and acceptance checks to the glassware, analytical procedure, safety data and approved site requirements.

Objective

Describe a controlled approach for cleaning, checking, drying and storing reusable glassware used in chemical and instrumental analysis. WHO good practices for pharmaceutical QC laboratories list cleaning of glassware among the activities that should be covered by laboratory procedures; they do not prescribe one universal cleaning agent or cycle. WHO TRS 1052, Annex 4, §3.7 (2024)

Scope

This example applies to reusable laboratory glassware in a pharmaceutical QC laboratory. Use separate approved instructions where the analytical method, glassware manufacturer, material or residue requires a specialized process. This template is not a validated cleaning method and does not set universal rinse counts, chemical concentrations, soak times or oven conditions.

Responsibilities

• Analyst or technician: identify the glassware and residue, follow the approved cleaning instruction, inspect the item and report damage or suspected contamination.
• Laboratory supervisor: ensure staff are trained on applicable instructions and that suitable cleaning supplies, storage and safety controls are available.
• Quality unit or designee: review and approve controlled procedures and documented changes under the site’s quality management system.

Procedure

Prepare for cleaning

1. Identify the glassware, its intended analytical use and any special cleaning requirements in the method or manufacturer instructions.
2. Separate items by material and residue. Do not combine incompatible chemicals or mix cleaning agents. Review relevant safety data sheets and the laboratory risk assessment before handling hazardous residues.
3. Use suitable protective clothing and equipment. Handle broken or chipped glassware with the approved procedure for sharps and contaminated waste.

Clean and rinse

1. Remove or contain remaining sample and reagent residues using the applicable waste procedure.
2. Clean with a suitable detergent or approved cleaning method compatible with the glassware and the subsequent analysis. Use brushes or a glassware washer only when they are suitable for the item and do not damage calibrated surfaces.
3. Rinse with the water quality and sequence specified by the analytical method or approved site procedure. Use a final rinse suitable for the intended test. Do not assume a fixed number of rinses is sufficient for every method or residue.
4. Use special cleaning procedures for Gooch crucibles, silica glass, platinum crucibles or other materials when their manufacturer or method requires them. The approved procedure should state compatible agents, handling, rinsing, drying and waste disposal. Do not apply acid treatment, chromic-acid mixture or high-temperature firing based on this generic template.

Check, dry and store

1. Inspect each item under suitable lighting for visible residue, damage or signs of contamination. Remove unsuitable items from use and report them according to local procedure.
2. Dry using the method allowed by the analytical method and glassware manufacturer. Some procedures require glassware to be dry; others specify a different preparation, so do not assume oven drying is always suitable.
3. Store cleaned items in a protected area or covered container to prevent dust, handling contamination and mix-ups. Keep clean glassware separate from used items.

Example in-house criterion (not a pharmacopoeial requirement): the laboratory may require a documented visual check for visible residue and damage before releasing selected glassware for use, with additional suitability checks when the analytical method is sensitive to carryover or residues.

Safety and waste

Follow the approved hazard-specific procedure for detergents, acids, solvents, residues, broken glass and cleaning waste. Keep chemical-specific instructions available to staff and use suitable protective equipment. WHO guidance describes risk-based safety procedures and safe waste management for pharmaceutical QC laboratories. WHO TRS 1052, Annex 4, §§7.1–7.5 (2024)

Records and retention

Record cleaning activities when required by the applicable method or site procedure. Retain batch-associated production, control or distribution records required under US cGMP for at least one year after the related batch expiry, subject to specific exceptions. EU GMP batch documentation must be retained for at least one year after batch expiry or five years after Qualified Person certification, whichever is longer. Retain other cleaning records for the period set by applicable law, contract and the site’s controlled schedule. 21 CFR §211.180(a) (current eCFR); EU GMP Part I, Chapter 4, §4.11 (January 2011)

Training

Train personnel on the approved procedure and applicable hazard controls before they perform the work. Document training under the site’s training system.

Abbreviations

• QC: quality control
• SDS: safety data sheet
• SOP: standard operating procedure

See also cleaning laboratory instruments and equipment, handling laboratory reagents and cleaning validation.

Frequently asked questions

How many times should glassware be rinsed?

Use the rinse sequence in the approved method or site procedure. The appropriate final rinse depends on the residue, water quality and intended analysis; this template does not establish a universal number.

Should all glassware be oven dried?

No universal drying condition applies to every glassware type or method. Follow the analytical method and manufacturer instructions, and use only an approved drying process.

Can strong acids or chromic-acid mixtures be used for routine cleaning?

Only use a specialized chemical cleaning method if it has been assessed and approved for the material and residue, and the procedure defines handling and disposal controls. This template does not authorize a particular acid treatment.

References

• World Health Organization. WHO good practices for pharmaceutical quality control laboratories. WHO Technical Report Series No. 1052, Annex 4, 2024, §§3.7 and 7.1–7.5. Official WHO publication and PDF.
• European Commission. EudraLex Volume 4, EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use, Part I, Chapter 4: Documentation, §4.11, revision 1, January 2011. Official Chapter 4 PDF.
• United States. Code of Federal Regulations, Title 21, Part 211, §211.180(a), General requirements, current eCFR, accessed 16 October 2026. Official eCFR text.