Question

Which one of the following solutions is used to disinfect flexible endoscopes?

• A. 10% chlorhexidine
• B. Absolute alcohol
• C. 2% Glutaraldehyde
• D. 5% Peracetic acid

Hint:

Think about which agent gives high-level disinfection without damaging heat-sensitive optics.

Answer 1

The Correct Option is C

This question is testing which chemical disinfectant is actually compatible with a heat-sensitive flexible endoscope.

1. 10% chlorhexidine: chlorhexidine is an antiseptic for skin and mucosa, not a high-level disinfectant - it will not reliably kill mycobacteria or bacterial spores, so it is ruled out.
2. Absolute alcohol: alcohol coagulates and fixes protein debris onto the scope surface and flashes off too fast to give adequate contact time in the internal channels, so it is ruled out.
3. 2% Glutaraldehyde: this is the agent purpose-built for reprocessing flexible endoscopes - it achieves high-level disinfection in about 20-30 minutes without corroding lenses or the scope sheath, so this is the correct choice.
4. 5% Peracetic acid: peracetic acid can disinfect equipment, but not at this concentration or as a simple soak - it is not the recognised endoscope-disinfection solution, so it is ruled out.

Correct answer: 2% Glutaraldehyde.