8.1 Acceptable Instrument Identification & Marking Methods
Key Takeaways
- Acceptable marking methods include autoclavable instrument marking tape, dipped or moulded polymer handle coatings, laser etching, and electrochemical etching.
- Any marking method must be autoclavable, non-toxic, non-porous, must not create a crevice, and must not interfere with function or cleaning.
- Marks are never applied to jaws, box locks, ratchets, cutting edges, insulated surfaces, or any working or articulating surface.
- Rubber bands, adhesive labels, nail polish, permanent marker, and paint are not acceptable instrument identification methods.
- Colour coding identifies the owning set, service, or size, while laser-etched 2D codes provide unique identity for instrument-level tracking.
Why Instruments Are Marked
Marking answers questions that count sheets cannot answer quickly: which set does this belong to, which service owns it, what size is it, and — with a unique code — exactly which instrument is this? In a department processing thousands of items a day, identification is what keeps instruments from migrating between sets and services.
The Acceptable Methods
| Method | What it is | Best for |
|---|---|---|
| Instrument marking tape | Autoclavable, colour-coded tape wrapped on the shank or ring | Set, service, or size coding; reversible |
| Dipped / moulded handle coating | Polymer applied by the manufacturer or a vendor to the rings or handle | Durable colour coding, comfortable grip |
| Laser etching / laser marking | Permanent mark burned into the surface, including 2D data matrix codes | Unique identity for instrument-level tracking |
| Electrochemical etching | Permanent mark applied by controlled electrolytic process | Text and codes; vendor applied |
| Colour anodizing | Oxide colour layer on titanium and aluminium | Manufacturer-applied size/service coding |
| Marking rings / bands (validated products) | Autoclavable silicone or polymer bands | Quick set coding on shanks |
What Makes a Method Acceptable
A marking method must satisfy every one of these:
- Autoclavable / process-compatible. It must survive the facility's cleaning chemistry and sterilization method without degrading, discolouring, or releasing residue.
- Non-toxic and biocompatible.
- Non-porous, with no crevice. It must not create a gap, ledge, or absorbent surface where soil and moisture can lodge.
- Sterilant-permeable or negligible. It must not shield a functionally important surface from steam.
- Functionally neutral. It must not change balance, obstruct articulation, prevent full closure, or alter the working surface.
- Removable or maintainable where applicable, so a worn mark can be replaced rather than accumulating layers.
What Is Not Acceptable
| Not acceptable | Why |
|---|---|
| Rubber bands | Complete sterilant barrier; degrade and shed; not a marking method |
| Adhesive paper or plastic labels | Not autoclavable; peel and leave residue; harbour soil |
| Nail polish, paint, correction fluid | Not validated, not biocompatible, chip and flake into the wound |
| Permanent marker | Not durable; residue |
| Scratched or engraved marks made in-house | Break the passivation layer and start corrosion; create crevices |
| Tape wrapped over a working surface | Barrier to sterilant; interferes with function |
| Multiple layers of old tape | Crevices, soil retention, and unknown cumulative thickness |
The scratched-mark item deserves emphasis. Cutting into the surface of stainless steel destroys the chromium oxide passivation layer at the mark and leaves a rough channel. Corrosion begins there and progresses. This is why permanent marking is done by laser or electrochemical processes designed for the purpose, by people who do it as a controlled process — not with an engraver at the bench.
Where Marks May Be Placed
Acceptable locations
- The shank, between the box lock and the ring handles, on a flat, non-articulating area
- The finger rings (dipped coating or tape)
- A flat area of a solid instrument such as a retractor handle
- Any location the manufacturer specifies for its own marking
Prohibited locations
| Location | Why |
|---|---|
| Jaws, tips, serrations | Working surface; barrier to function and cleaning |
| Box lock | Articulating; the mark is destroyed and creates a crevice |
| Ratchet teeth | Prevents engagement |
| Cutting edges | Obvious |
| Insulated shafts | A mark can conceal or create an insulation defect |
| Lumen openings and ports | Obstruction |
| Any area the IFU excludes | Manufacturer restriction governs |
Colour Coding Versus Unique Identification
These are different jobs and are often confused.
| Colour coding | Unique identification | |
|---|---|---|
| Question it answers | "Which set/service/size?" | "Which specific instrument is this?" |
| Typical method | Tape, dipped handles, anodizing, bands | Laser-etched 2D data matrix |
| Granularity | Group | Individual |
| Supports | Sorting, set integrity, size selection | Instrument-level tracking, repair history, use counts |
A facility that wants instrument-level tracking (Section 4.6) needs unique marks; a facility that simply wants to keep the ortho sets out of the general sets needs colour coding. Many departments run both.
Colour-coding discipline matters. A colour scheme is only useful if it is documented, consistent facility-wide, and taught. Two services using the same colour for different meanings is worse than no colour coding at all, because staff act on it confidently and wrongly. The scheme belongs in a written policy alongside the count sheets.
Matching the Method to the Instrument
An acceptable method is not acceptable on every instrument, and this is where a well-intentioned marking programme does damage. Before marking anything, ask whether this particular instrument can carry a mark at all.
Micro and delicate instruments — ophthalmic, otologic, microvascular, and fine neurosurgical items — generally cannot take tape. The added thickness changes balance on an instrument weighing a few grams, and there is often no flat, non-functional surface wide enough to wrap. These are identified instead by their dedicated cases, brackets, and stringer positions, or by manufacturer-applied marking.
Insulated electrosurgical instruments must not be marked on the insulated shaft. Tape can conceal an existing defect from both visual inspection and the insulation tester, and applying and removing it stresses the coating. Mark the handle or hub only.
Endoscopes, camera heads, and light cables are marked only by methods the manufacturer approves. Tape on a scope shaft interferes with sheath fit and with cleaning, and adhesive residue on an optical surface is unrecoverable.
Powered handpieces and their attachments are marked only where the manufacturer permits, never over vents, ports, chucks, or moving components.
Titanium instruments are frequently already colour-anodised by the manufacturer, and adding tape over that defeats the purpose while creating a crevice.
The general test is whether the mark sits on a flat, non-functional, non-sealing, non-articulating, non-insulated surface with room for a proper overlap. If no such surface exists, the instrument is identified by another means.
When an Instrument Arrives Unmarked or Marked Wrongly
Two situations recur at the assembly bench, and each has a defined response.
An unmarked instrument in a marked set. Do not simply add tape in the set's colour and move on. First confirm the instrument actually belongs to that set by checking it against the count sheet, because an unmarked instrument is frequently a migrant from elsewhere. If it does belong, mark it correctly and record that you did; if it does not, return it to its own set.
An instrument bearing the wrong colour. This is a stronger signal, because it usually means the instrument has migrated and some other set is now short. Identify the correct owner from the colour scheme, verify against that set's count sheet, and return it. Removing the old tape and re-marking it for the tray in front of you resolves your immediate problem while permanently concealing the other set's shortage.
In both cases the useful output is the pattern. Instruments that repeatedly migrate between two sets usually indicate that the two sets are processed together, stored together, or opened together in the operating room, and that is a fixable workflow issue rather than an endless re-taping task.
Why is scratching or engraving an identification mark into an instrument at the bench unacceptable?
Which location is acceptable for instrument marking tape on a hemostat?
A department uses colour-coded tape to identify which service owns each set. What single condition makes the scheme genuinely useful?