SOP: Entry, Exit and Gowning in Non-Sterile Microbiology Lab

In short: This example SOP shows how analysts enter and leave a non-sterile microbiology testing area and gown correctly, to protect samples and media from contamination and protect people from cultures. Adapt it to your own layout and quality system.

Regulatory background

WHO good practices for pharmaceutical microbiology laboratories (TRS 961, Annex 2, 2011) say access to the microbiology laboratory should be restricted to authorised personnel who know the entry and exit procedures, including gowning (section 2.1.5), and that hand-washing and hand-disinfection facilities should be available (2.3.3).

Be careful which document you cite for what:

• WHO TRS 1052 Annex 4 (QC laboratories) states that it does not cover microbiology laboratories and points to the microbiology guideline above.
• Sterile-garment rules (EU GMP Annex 1, 2022; WHO sterile GMP) apply to clean rooms used for sterile manufacturing (grades A to D) and to sterility-test facilities, not to an ordinary non-sterile testing area. If your lab also has a sterility-test facility, its operators must follow those sterile principles and be trained and certified in gowning, with training records kept (TRS 961 Annex 2, 2.4.9).

The sterile gown, head cover and boot-cover requirement below is an example in-house criterion, not a regulatory requirement for a non-sterile area.

1. Objective

To describe the procedure for entering and leaving the microbiology testing area and for gowning.

2. Scope

Applies to all persons entering the non-sterile microbiology testing area.

3. Responsibility

• Microbiologist and lab assistant: follow the procedure.
• Head of Microbiology: ensure implementation and training.

4. Procedure

The layout description (airlock, change room, footwear change, testing area) must match your facility. Attach a floor plan as an annexure.

4.1 Before entry

• A person with cough, cold, fever, skin infection or open wound must not enter and must tell the supervisor. This is an example in-house criterion.
• Remove outdoor jackets and personal items; no jewellery, watches or cosmetics.

4.2 Entry and gowning (example steps)

1. Remove outdoor footwear at the line of demarcation and wear dedicated laboratory footwear in the first change area.
2. Wash and sanitise hands.
3. Take a sterile gown bag containing head cover, gown and boot covers. Check that the bag is intact and in date.
4. Put on head cover (hair fully covered), then gown, then boot covers, without letting garments touch the floor.
5. Put on sterile, powder-free gloves and sanitise them with the approved disinfectant.
6. Enter the testing area through the airlock. Both doors of the airlock must not be open at the same time.

4.3 Re-entry

Each time a person re-enters, repeat the full procedure with a fresh gown bag (head cover, gown, boot covers, gloves). Do not reuse discarded gowns or gloves.

4.4 Exit

1. Remove gloves, boot covers, gown and head cover in the exit change area and place them in the marked disposal or laundry bins. Contaminated disposable items are decontaminated before disposal as per the waste SOP.
2. Wash hands.
3. Change back to outdoor footwear.

5. Records and retention

Record entry and gowning training in the training file. Where an entry logbook is used, keep it at least 1 year after the expiry date of the respective product batch (EU GMP Part I Chapter 4 section 4.11, or 5 years after QP certification if longer; 21 CFR 211.180(a)), longer if local law or the marketing authorisation requires.

6. Training

Train and assess personnel on gowning before they work independently, and retrain as per the training SOP.

7. Abbreviations

SOP: standard operating procedure. QP: Qualified Person.

8. Annexures

Floor plan of the entry and exit route (to be attached by the site).

9. Revision history

Frequently asked questions

Do we need sterile gowns in a non-sterile microbiology lab? Not by regulation. Clean or sterile garments are a site decision based on risk; this example uses sterile gowns as an in-house criterion.

Does Annex 1 apply here? Only to sterile manufacturing areas and, by extension, sterility-test suites.

Related reading

• SOP for good microbiological laboratory practice
• Checklist for microbiological analytical data and reports

References

1. WHO Technical Report Series No. 961 (2011), Annex 2: WHO good practices for pharmaceutical microbiology laboratories, sections 2.1.5, 2.3.3 and 2.4.9.
2. WHO Technical Report Series No. 1052 (2024), Annex 4: WHO good practices for pharmaceutical quality control laboratories (scope, paragraph 1.6).
3. EU GMP Part I, Chapter 4: Documentation, section 4.11; 21 CFR 211.180(a).
4. EudraLex Volume 4, Annex 1: Manufacture of Sterile Medicinal Products (C(2022) 5938, published 25 August 2022; for sterile areas only).