Why is 70% ethanol used to sterilize skin before injections instead of 95% ethanol?
A) 70% ethanol kills bacteria by denaturing their surface proteins.
B) 70% ethanol penetrates bacteria and kills them by coagulating their proteins.
C) 70% ethanol can kill bacteria without damaging their structures.
D) None of these are correct.

Question

Quizplus · Accepted Answer

70% ethanol is more effective than 95% ethanol because it penetrates bacterial cells better, allowing it to coagulate proteins and kill the bacteria. Higher concentrations like 95% ethanol can cause proteins to coagulate on the surface, creating a protective barrier that prevents further penetration.

Why Is 70% Ethanol Used to Sterilize Skin Before Injections