Why brush selection matters (and why “close enough” isn’t enough)
Reprocessing is a multi-step process (cleaning, inspection, packaging, sterilisation, storage), and cleaning is the step that removes soil and bioburden so downstream processes can be effective.
When the brush is wrong—too small, too large, too stiff, too short—you can end up with:
- residual soil in lumens and joints,
- surface damage that creates retention sites,
- inconsistent outcomes between technicians,
- nonconformance with IFUs.
Those risks are precisely why Australian guidance focuses on structured processes and risk management for reprocessing activities.
Step 1: Start with the device IFU and “hardest-to-clean” features
Your first checkpoint should always be the manufacturer’s IFU. The NSQHS advisory for reprocessing explicitly ties reprocessing processes to national standards in conjunction with manufacturers’ guidelines—so brush choice should be defensible against the IFU, not simply tradition or convenience.
A useful way to build a brush range is to map common instrument challenges:
- Lumens/cannulations (long, narrow pathways)
- Serrations and jaws
- Box locks/hinges
- Knurled surfaces and threads
- Delicate coatings or fine finishes
Tip for CSSD Managers: standardise your brush kits around the most difficult device types you process routinely, then ensure the kit also covers everyday general instruments.
Step 2: Match brush diameter, length, and geometry—especially for lumens
For lumened devices, brush selection is primarily an engineering match:
- Diameter: the brush should contact the internal surface without binding or shedding.
- Length: must reach the full lumen length (including bends where relevant).
- Tip design: rounded/atraumatic tips help protect internal surfaces.
- Shaft rigidity: enough stiffness to navigate the channel, but not so rigid it damages surfaces.
Practical brush set suggestion (non-prescriptive):
- micro-lumen brushes (very small diameters)
- standard channel brushes (multiple diameters)
- long channel brushes and endoscopy brushes (extended lengths)
- toothbrush-style brushes for serrations/hinges
- wide surface brushes for trays and larger items
Step 3: Choose the right bristle material and stiffness to remove soil without damaging instruments
Brush bristles must be effective at soil removal while avoiding micro-damage to instrument surfaces (which can create retention points for soil and interfere with cleaning effectiveness over time).
What to consider when selecting bristles:
- Soft bristles for delicate finishes and fine instruments
- Medium bristles for general instrument surfaces
- Stiffer bristles for robust items with heavy soil loads (used carefully and only if consistent with IFU)
Also consider bristle retention/shedding and whether the brush construction is compatible with your cleaning chemistry and process.
Note: Stainless steel bristle brushes should be used with extreme caution in the CSSD and are generally not recommended for routine cleaning of stainless-steel surgical instruments. Their abrasive nature can scratch instrument surfaces and damage the protective passive layer, creating microscopic retention sites for soil and moisture, increasing corrosion risk, and ultimately making instruments harder to clean effectively over time.
Step 4: Decide single-use vs reusable brushes using an infection-prevention risk lens
Single-use vs reusable shouldn’t be decided only on unit cost. Instead, evaluate:
- contamination and handling risks,
- complexity of cleaning the brush itself (if reusable),
- workflow compliance and human factors,
- the device category and soil load.
Rule of thumb: for high-risk, intricate, or difficult-to-clean devices, single‑use brushes can reduce cross‑contamination risk and variability—particularly where brush reprocessing is hard to validate consistently—without making any claim regarding environmental impact, which should be assessed separately.
Step 5: Standardise, colour-code, and train: brush selection is a system, not a drawer of options
Even a perfect brush range fails if staff can’t select quickly and consistently. Consider building a simple “brush selection system”:
- Colour-coding by diameter/length range
- Shadow boards or labelled storage at point-of-use
- Quick-reference charts mapped to common device families
- Competency checkoffs for new staff and annual refreshers
Also, consider periodically auditing brush condition (wear, deformation) and replacing worn brushes—because worn bristles can reduce cleaning effectiveness and create variability between shifts.
Conclusion: Make brush choice part of your compliance strategy
In Australian CSSD, choosing surgical cleaning brushes should be treated as part of your reprocessing quality system—tied to IFUs, matched to device complexity, and supported by training and standardisation. With AS 5369 referenced across national reprocessing guidance and resources, brush selection is one of the simplest ways to improve cleaning outcomes and demonstrate a mature, standards-aligned approach.
This article is intended for healthcare professionals involved in medical device reprocessing and sterile services. It is provided for general educational purposes and should be read in conjunction with applicable standards and manufacturers’ instructions for use (IFUs).