Every sterile box carries a short code that most people never read. It is the lot number, and it is the only thing that connects the cartridge in your hand to the day it was sterilised, the batch it was made in, and every other box from the same run. This note is about how to read it, what it lets you trace, and why we record it for every box we ship.
What is printed on a sterile box
| Field | Usually marked as | What it tells you |
|---|---|---|
| Lot (batch) | LOT, followed by letters and digits | The production and sterilisation run this box belongs to |
| Sterilisation date | A date, sometimes only month and year | When the run was sterilised |
| Expiry | An hourglass symbol, or EXP, and a date | The last date the sterile claim holds, if the seal is intact |
| Method | EO, STERILE EO, or a gamma symbol | How it was sterilised |
| Single use | A crossed-out 2 | Do not reprocess or reuse |
Formats vary by manufacturer and the symbols follow the medical-device conventions most studios already know from other supplies. If a box carries no lot at all, that is the finding: there is nothing to trace.
What a lot lets you trace
A lot number turns a vague worry into a specific question. If a client reacts, if a seal is found open, if a manufacturer announces a problem with a run, the lot is what says whether your box is affected. Without it, every box you own is suspect. With it, the question is answerable in a minute.
What we do with it
When a lot arrives here, we record the lot number, the sterilisation date and the expiry for every box before it goes on the shelf, and the spec sheet shows the lot once we have it. Every restock is recorded against the studio that received it. So if a lot is ever recalled, by us, by a manufacturer or by an authority, we know which studios have it and we contact each one; the procedure is written in Returns and recalls, and the promise is in Standards.
What a studio should do
- Keep the box until the last unit is gone. The lot lives on the box, not on the cartridge.
- Where your local rules require it, note the lot in the client record. Many do not require it; it is still the habit that makes a recall answerable.
- Check the lot against the dispatch note when a restock arrives. If they do not match, tell us before you use anything.
- If a seal is open or the expiry has passed, set the unit aside and write to us with the lot and a photo.
None of this takes more than a minute a box. It is the difference between a supplier that sells needles and one that can say where every needle went.