4.2 Manual Cleaning

Cleaning Comes First — Always

Cleaning is the physical removal of soil and bioburden from a device. It is the single most important step in instrument reprocessing because a device cannot be reliably disinfected or sterilized if it is not first clean. Soil left on an instrument can harbor organisms, block the sterilant from contacting the surface, and bake onto the device during sterilization. The reprocessing hierarchy is fixed and heavily tested: clean → inspect → package → disinfect/sterilize. Skipping or shortchanging cleaning invalidates every step that follows.

Manual cleaning is hand cleaning of instruments in a sink, using friction, water, and a chemical (an enzymatic or neutral-pH detergent). It is performed in the decontamination area while wearing full personal protective equipment (PPE): fluid-resistant gown, gloves, surgical mask, and a full face shield or goggles, with the area maintained at negative pressure relative to adjacent clean spaces so contaminated air does not drift outward.

Manual cleaning is essential for devices that automated equipment cannot safely or fully clean: delicate microsurgical and ophthalmic instruments, air-powered drills and electrical hand pieces (which usually cannot be immersed or run through standard washer cycles), endoscopic and robotic instruments, and any device whose IFU specifies manual steps. Many complex instruments require manual cleaning of channels and crevices even when the rest of the cycle is automated — the manual step removes soil from internal lumens before the washer-disinfector finishes the job.

Two Sinks, Defined Workflow

A proper manual-cleaning station uses a two- or three-bay sink: a wash bay holding the detergent solution and a separate rinse bay, so cleaned items move forward and never back into the dirty wash water. Water temperature and detergent concentration are set per the detergent IFU before instruments are submerged.

The Manual Cleaning Technique

The technique matters as much as the chemistry. Two rules dominate the CIS exam.

1. Clean Below the Water Surface

All brushing and scrubbing must be done with the instrument and brush fully submerged below the surface of the water. Brushing above the waterline creates aerosols — fine contaminated droplets that can be inhaled or splashed, spreading bioburden around the room and onto staff. Keeping the action underwater physically traps the droplets in the solution. This is one of the most frequently tested manual-cleaning safety points.

2. Use Friction and the Right Brush

• Friction (the mechanical scrubbing action) is what physically dislodges soil. Detergent loosens and emulsifies soil, but friction removes it. Soaking alone is not cleaning.
• Open box locks and ratchets and disassemble multi-part instruments per the IFU so detergent and friction reach hinge, jaw, serration, and box-lock surfaces where soil collects.
• Use soft-bristled brushes (usually nylon) — never steel wool or abrasive pads, which scratch the passive layer and create corrosion sites.
• Serrations, box locks, and jaws are scrubbed with a small soft brush worked directly into the grooves and teeth.
• Lumens and cannulated instruments are cleaned with a brush sized to the lumen (the brush must contact the channel wall), pushed all the way through until it exits the far end so debris is pushed out rather than packed in, then flushed. The brush is then cleaned/decontaminated if reusable, or discarded if single-use.

Brush Sizing Rule

A brush that is too small slides through without touching the lumen wall and removes nothing; a brush that is too large jams, frays, or cannot pass. Match brush diameter to the channel as the IFU specifies. The same logic applies to manifold flush ports on channeled devices — connect the correct adapter so fluid actually runs through the channel.

Matching the Method to the Instrument

CIS-level knowledge means choosing the correct cleaning method for the device. The table summarizes common surgical-instrument scenarios.

The IFU Governs Everything

The governing rule for all of these is the device IFU: it specifies disassembly steps, brush sizes, detergent type, water temperature, immersion limits, and whether the device may be automated at all. When the IFU and a general practice seem to conflict, the IFU wins — it is the legally validated, device-specific instruction.

Trap: Powered Hand Pieces

A recurring exam scenario presents an air-powered drill or pneumatic saw. The wrong answer is always "immerse it and run it through the washer." Powered hand pieces typically have internal motors, bearings, and lumens that water and detergent would corrode or that retained moisture would seize. They are wiped, brushed at the ports, and never soaked, with the IFU dictating the exact steps and any flushing of the air channel. Treating a powered device like a simple stainless instrument is a classic, costly error the CIS must prevent.