An intervention is a planned breach of the critical zone: a jam cleared, a sensor adjusted, a component added. The wipe used during that breach is handled by the same gloved hand that will touch the filling needle, which makes it a critical supply rather than a cleaning accessory.
One hand, one motion
Inside a Grade A zone, the operator has one free hand and limited movement. A wipe that has to be unfolded, separated from a stack or shaken open costs seconds and generates particles. A pre-wetted, individually packed wipe can be opened and used in a single motion, which is why the format is common at the intervention point.
Size matters in the opposite direction from a bench wipe. A large sheet is harder to control with one hand and more likely to contact a surface outside the intended area. The 23 × 23 cm format exists for this reason, not because it is cheaper to convert.
The barrier stack is part of the wipe
A sterile wipe is only sterile until the outer bag is opened. The transfer sequence, the number of bags and the point at which each is opened should be written down and practised. A triple-bagged pack is not a guarantee; it is a sequence that has to be followed.
In practice: wipe the outer bag at the airlock, transfer it into the Grade B area, open the outer bag there, and carry the inner bag to the point of use. Open the inner bag only when the intervention begins, and never leave an opened inner bag on the floor of the zone.
Residue at the critical surface
The surface being wiped may be a filling needle, a stopper bowl or a sensor window. Residue from the wipe can change how a subsequent sterilisation behaves or leave a film that interferes with a sensor. The specification should name the extractables limit and the solvent, and the certificate should report the same method.
For a dry wipe used with a sprayed surface, the residue profile is dominated by the solvent. For a pre-wetted wipe, the solution is part of the product and has to be justified in the CCS.
Monitoring and the record
The intervention should be recorded with the time, the reason and the consumable lot. If an environmental monitoring result moves after the intervention, the lot number is the first thing that lets you check whether the consumable changed. Without it, the investigation starts from memory.
Keep the lot record with the batch record, not in a separate consumables file. The two are only useful together.
| Decision | Typical choice | Reason |
|---|---|---|
| Format | Individually packed, pre-wetted | One-hand opening, fixed dose |
| Size | 20–23 cm square | Control inside the zone |
| Sterility | SAL 10-6, triple bagged | Transfer into Grade A |
| Documentation | Lot, CoA, extractables | Traceable to the batch |
The intervention kit
Assemble the consumables for an intervention as a kit: one sterile wipe pack, one pair of sterile gloves, a labelled waste bag for the wrappers. The kit is prepared in the Grade B area and opened only when the intervention starts.
A kit removes the search for a missing item during a breach. It also makes the consumption visible: if a kit is opened, there was an intervention, and the batch record should say so.
Can a dry sterile wipe be used with a sprayed disinfectant?
Yes, if the solvent and the residue are covered by the CCS and the wipe is sterile. The advantage is that the dose is under the operator's control; the disadvantage is that it adds a step inside the zone.
How many wipes should be in an intervention pack?
Enough to finish the task without opening a second pack. A pack that runs out mid-intervention forces a second transfer, which is a second breach and a second record.
Should the wipe be weighed before use?
Not routinely. Weighing is a qualification activity that confirms the fill weight of the pack, not a per-intervention check. The certificate covers the lot.
