Which feature distinguishes alcohol-based CHG prep from aqueous CHG prep?

• A. Alcohol-based CHG dries quickly and offers rapid action; aqueous CHG lacks alcohol's fast evaporation.
• B. It requires longer contact time than aqueous CHG.
• C. It stains skin more than aqueous CHG.
• D. It is more expensive and has no clinical difference.

Answer: (A)

The main idea here is that the alcohol component in CHG prep changes how quickly the skin dries and how rapidly it acts. Alcohol evaporates quickly, which drives fast drying and leaves a thin, adherent CHG layer on the skin. That rapid evaporation plus the antiseptic action of CHG means the prep can be completed sooner and delivers immediate antimicrobial effect. Without alcohol, the aqueous form stays wet longer and the rapid evaporation-driven action isn’t present, so drying is slower and the immediate fast-action benefit is reduced.

So, the feature that sets alcohol-based CHG apart is its quick drying and rapid antimicrobial action due to the alcohol. The other statements aren’t the defining difference: contact time is not inherently longer for the alcohol-based version; staining can occur with CHG but isn’t the distinguishing trait; and cost with no clinical difference isn’t accurate because the quick-drying, rapid-action advantage is a real clinical distinction.