GLI GLI Quality Tool
GLI Quality Tool — Version 2.0

Building a Practical TB Workbench Contamination Scoring Tool

A well-designed workbench assessment helps a tuberculosis laboratory detect contamination risks before they affect staff safety, test validity or confidence in reported results. The tool should turn routine observations into consistent evidence, rather than relying on individual judgement or a general impression that a bench “looks clean”.

For Australian laboratories, the assessment must work across metropolitan hospitals, regional pathology services and smaller facilities with limited staffing. A laboratory in Sydney or Melbourne may have dedicated biosafety personnel, while a service in Darwin, Alice Springs or a remote Queensland community may need a simpler process that can be completed by the senior scientist on duty.

The aim of designing a TB lab contamination control assessment scoring tool for workbenches is to connect daily practice with a quality management system. It should support local procedures, NATA expectations, relevant work health and safety duties, and the laboratory’s own risk profile without creating paperwork that staff cannot maintain.

Define The Scope Before Scoring

Start by stating exactly what the assessment covers. A workbench may include the surface where specimens are opened, the area used for smear preparation, a biological safety cabinet, nearby racks, centrifuge controls, pipettes, waste containers and frequently touched handles. The score should distinguish between these zones because their contamination risks are different.

The tool should focus on practical controls for TB specimen handling. These may include separation of clean and dirty activities, correct use of disinfectant, control of aerosols, safe placement of specimen containers, bench decontamination between batches, and the management of spills. It should not become a broad laboratory housekeeping audit unless those issues directly affect contamination control.

Define the review unit as well. A useful approach is to score each workbench or work zone separately and then produce a laboratory-level summary. This makes it easier to identify whether a problem is isolated to one cabinet, associated with a particular shift, or caused by a design issue affecting the whole department.

Translate Hazards Into Observable Criteria

Each scoring item should describe something an assessor can see, verify or trace to a record. “Good aseptic technique” is too broad to score reliably. A stronger criterion would ask whether clean consumables are stored away from potentially contaminated materials and whether staff can demonstrate the required sequence for handling them.

Consider the pathway of a TB specimen from receipt to disposal. Ask where contamination could occur, how it could spread and what barrier should prevent it. For example, an assessment may examine whether specimen containers are checked for leakage, whether the work surface is uncluttered, and whether contaminated waste is removed without crossing a clean preparation area.

Include equipment and environmental factors that influence contamination. A biological safety cabinet may be overdue for certification, have blocked grilles or be used for storage. A bench may be damaged, porous or difficult to disinfect. Airflow, room layout and placement of centrifuges can also matter, especially when laboratories have been adapted within older hospital buildings.

Set A Transparent Scoring Architecture

A simple four-point scale is usually easier to apply than a detailed numerical system. One possible model is: zero for absent or unsafe control, one for partial control, two for control that is present but inconsistently applied, and three for a consistently demonstrated and documented control. Include an “unable to assess” option so missing evidence is not accidentally treated as satisfactory.

The scoring guide should explain what separates each level. For instance, a disinfectant criterion might score three when the product is approved for the intended use, correctly prepared, labelled with expiry information and applied for the required contact time. It might score one when staff use a suitable product but concentration, preparation date or contact time cannot be verified.

Weight high-consequence items more heavily if the laboratory’s risk assessment supports it. Failure to control aerosols, incorrect biological safety cabinet use or unsafe spill response may deserve greater priority than untidy stationery or an unlabelled storage tray. Weighting should remain visible to users; hidden calculations reduce trust and make corrective action harder to explain.

A useful overall result can combine an average score with critical-failure rules. A workbench might achieve a reasonable percentage while still requiring immediate action because an essential containment control is absent. This prevents strong performance in low-risk areas from masking one serious weakness.

Gather Evidence During Each Review

Assessors should collect evidence in a consistent order. Begin with a short discussion with the staff member responsible for the area, then observe routine or simulated work, inspect the bench and equipment, and check related documents. The goal is to compare written procedure, actual behaviour and physical conditions.

Use the downloadable materials from the GLI Quality Tool to support local forms, instructions and quality management activities. Adapt them to the laboratory’s terminology and workflow rather than copying a generic form without testing it. A small pilot on two different shifts can reveal whether a criterion is clear enough for everyday use.

Records And Observations To Capture

Record evidence that can support the score:

Conditions Worth Checking

Inspect the conditions that can increase cross-contamination:

The form should include a comment field beside every low score. A number without context does not explain whether the cause was poor training, inadequate supplies, an unsuitable room layout or a procedure that is unrealistic during peak workload.

Use A Consistent Assessment Workflow

Assign trained assessors and define how often reviews occur. Monthly observation may suit a high-volume TB laboratory, while quarterly review may be adequate for a lower-throughput service if incident reporting and supervisory checks are active. Additional assessments should follow spills, equipment relocation, repeated nonconformities or changes to specimen volume.

Before scoring, confirm that the assessor understands the difference between observation and assumption. If a record is unavailable, the item should be marked as not verified rather than awarded a passing score. Staff should have an opportunity to explain unusual circumstances, such as a temporary bench closure or an urgent public health response.

Use the laboratory checklists as a reference when aligning workbench observations with broader quality systems. The checklist should sit within the laboratory’s document control process, with an owner, version number, review date and defined retention period for completed assessments.

Assessors should avoid disrupting clinical or public health testing. Observation can often be scheduled during routine work, but simulated demonstrations may be safer when live specimens are not being handled. In Australia, coordination with the state or territory TB program and the local pathology quality manager can help align the tool with service-level reporting expectations.

Interpret Results And Prioritise Action

Set action thresholds before the first assessment. For example, a high score may indicate routine monitoring, a middle score may require a corrective action plan, and a low score may require supervisory review and reassessment. Critical failures should trigger immediate containment measures regardless of the total score.

Corrective actions need an owner and a due date. “Remind staff to be careful” is not a sufficient response. Better actions might include replacing a damaged bench surface, revising the disinfectant preparation process, moving clean consumables outside the contaminated zone, arranging cabinet certification or conducting a focused competency assessment.

Analyse patterns over time rather than treating each score as an isolated event. A recurring low score on night shift may indicate limited supervision or supply access. Differences between Melbourne and regional services may reflect procurement delays, equipment support arrangements or staffing models rather than individual performance.

Report results in a way that protects learning. A dashboard can show the percentage of workbenches meeting critical controls, overdue actions and repeat findings. It should not be used as a punitive league table between laboratories, particularly when services operate with different workloads and infrastructure.

Link The Tool To Continual Improvement

A contamination scoring tool is valuable when it changes decisions. Review trends during quality meetings, connect findings to incident and near-miss reports, and check whether completed actions actually improve performance. If a score remains low after retraining, investigate the system rather than repeating the same training message.

Include staff who perform the work in tool reviews. Scientists, technicians, specimen reception staff, cleaners, supervisors and maintenance teams may each identify a different source of contamination risk. Their input is especially important when a laboratory uses shared benches, rotating staff or equipment purchased through a central health service contract.

Keep the tool proportionate. A one-page observation form with clear scoring notes may be more sustainable than a complex spreadsheet requiring extensive data entry. Digital forms can be useful where connectivity and device access are reliable, but a printable version should remain available for regional and remote settings.

Review the assessment itself at least annually, and after changes to TB testing methods, cabinet design, disinfectant products, room layout or regulatory requirements. The final measure of quality is whether the tool helps the laboratory maintain safe, repeatable workbench practices in everyday conditions.

Download the supporting resources, adapt the criteria to your laboratory’s hazards and trial the scoring tool across different shifts and work areas. Record the first findings, assign practical corrective actions and use the results to strengthen contamination control as part of routine TB laboratory quality management.