Alcohol pads, chlorhexidine or barrier wipes?
Use a 70% alcohol prep pad by default, and only alcohol on a vial stopper. Aqueous chlorhexidine is the alcohol-free antiseptic for skin that alcohol has made sore, and a barrier wipe is not an antiseptic at all: it goes on after cleaning, never instead of it.
Last edited · written by PepPrep · not medical advice
Three products do overlapping jobs on skin, and most people only ever meet the first one.
| Product | What it does | Reach for it when |
|---|---|---|
| Alcohol prep pad (70%) | The standard antiseptic wipe for skin and vial stoppers | Always — this is the default, and the only one you truly need |
| Chlorhexidine swab | A different antiseptic; the alcohol-free (aqueous) versions avoid the sting | Alcohol is drying or irritating your skin |
| No-sting barrier wipe | Leaves a thin protective film; it isn't an antiseptic | Skin is sore from repeated use — used alongside cleaning, not instead of it |
The mistake worth avoiding is treating a barrier wipe as a substitute for cleaning. It protects skin; it doesn't disinfect it. And whichever you use, the rule is the same: let it air-dry before the needle goes anywhere near it. Wet antiseptic carried in on a needle is what stings, and these products do their work as they dry.
For vial stoppers specifically, stick to alcohol — it's what the technique everyone teaches assumes, and it evaporates cleanly.
When you would prep differently
The three are not interchangeable, and the differences are equipment facts rather than judgement calls:
- A vial stopper takes alcohol, and only alcohol. Chlorhexidine leaves a residue on rubber and a barrier film is not made for it. The pads sold for stoppers are 70% isopropyl for that reason.
- Aqueous chlorhexidine is the alcohol-free one. Most chlorhexidine swabs sold for skin are chlorhexidine in alcohol, which stings exactly as much as an alcohol pad does. If the sting is your reason for switching, the listing has to say aqueous or alcohol-free — the colour of the wrapper tells you nothing.
- A barrier film goes on after cleaning, never instead of it. It is the product for skin that tape or repeated wiping has made sore, and it needs its own drying time on top of the antiseptic's. Two waits, not one.
- Individually sealed beats a tub. A tub of wipes dries out from the top down, so the last third is a dry cloth at the same price. Sealed pads cost a little more and are the same on day two hundred as on day one.
- Pad size is a real specification. The small pads sold in bulk are sized for a vial stopper, not for a patch of skin; if you are wiping an area, the larger pads cover it in one pass instead of three.
Everything about when to clean, and what to do when you realise you skipped a step, is in the sterile-technique guide. This page is only about which of the three wipes to keep in the drawer.
Supplies mentioned: Sterile Prep · Comfort & Safety
Equipment only: nothing on this page is advice about what to inject, how much, or whether a product is fit to use. That comes from the product's labelling and whoever supplied it.