Which antiseptic should be avoided before injection prep?

• A. Alcohol
• B. Chlorhexidine
• C. Iodine
• D. Hydrogen peroxide

Answer: (A)

Alcohol should be avoided for injection prep because it dries and irritates the mucosal tissues and evaporates quickly, which means it provides little reliable contact time or lasting antimicrobial effect at the injection site. This can make the injection more uncomfortable and may not give adequate surface disinfection. In contrast, chlorhexidine (with its persistent antimicrobial action) and povidone-iodine are commonly used for mucosal antisepsis and are generally better tolerated. Hydrogen peroxide can irritate mucosa and may interfere with healing if used on soft tissues, while iodine is effective but can cause staining or hypersensitivity in some patients. So alcohol is the least suitable choice for prepping an injection site.