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◆ Quality Series · Part 1
In short: a prep pad's performance rests on four attributes — alcohol concentration, fluid (saturation) volume, pouch seal integrity and bactericidal efficacy. They are not independent: weaken one and the others fail with it. This chapter explains how they connect and how we hold each in spec on every batch.
The four attributes that decide whether a pad works
| Attribute | What we hold to | Why it matters |
|---|---|---|
| Alcohol concentration | 75% ethanol (±10% v/v) — or 70% IPA on request | Drives antiseptic performance; off-target = weak kill |
| Saturation / fluid volume | Defined per size (0.4 ml for 65×30 mm up to 12.5 ml for 300×300 mm) | Too little and the pad under-wets the skin or dries out |
| Pouch seal integrity | Sealed and leak-free — vacuum 500 mmHg held 10 min | A weak seal lets alcohol evaporate before use |
| Bactericidal efficacy | ≥5 log (S. aureus, P. aeruginosa); ≥4 log (C. albicans) at 3 min | The end result patients and buyers rely on |
Why they're interlinked, not independent
It is tempting to treat these as four separate boxes to tick. In practice they form one cause-and-effect chain:
- Concentration and volume drive efficacy. If the ethanol drifts below target, or the pad carries too little fluid, the kill performance drops even though everything else looks fine.
- Seal integrity protects both over time. Alcohol is volatile. A pouch that does not hold a perfect seal slowly loses alcohol to evaporation — so concentration and fluid volume fall together across the product's shelf life, and efficacy goes with them.
That is why we treat the pouch seal as a quality attribute in its own right, not just packaging: it is what keeps the first three attributes true on the day the pad is actually opened — which may be years after it left the line.
The kill data we test to
Efficacy is verified by a quantitative suspension method against representative organisms:
| Organism | Contact time | Log reduction |
|---|---|---|
| Staphylococcus aureus | 3 min | ≥ 5.00 |
| Pseudomonas aeruginosa | 3 min | ≥ 5.00 |
| Candida albicans | 3 min | ≥ 4.00 |
How we hold it on every batch
- Concentration: compounded to 75% ±10% and verified with a calibrated alcohol meter, with readings temperature-corrected to 20 °C.
- Fluid volume: metered fill matched to each size, checked at first-article and during in-process patrols.
- Seal: in-process seal checks plus a vacuum leak test (500 mmHg / 10 min) per batch.
- Release: finished-lot testing across all attributes before an authorised release; a COA per lot; retention samples kept and observed.
- Traceability: ISO 13485 batch records tie raw-material lots to the production batch, so any result can be traced back.
For buyers — what to ask for: a COA per lot showing alcohol concentration and kill-log results; confirmation that seal/leak testing is run on every batch; and the retention-sample policy. A supplier that can hand these over without hesitation is controlling all four attributes, not just one.
