CRCST Practice Exam 2025 – Comprehensive All-in-One Guide to Exam Success

Ortho-phthalaldehyde is the correct answer because it is a high-level disinfectant that is approved for disinfecting flexible endoscopes. It has broad-spectrum microbicidal activity and is effective against a wide range of microorganisms, making it suitable for the high-level disinfection required for endoscopes.

Alcohol is not a high-level disinfectant and is generally used for low-level disinfection on the skin. Chlorine is more commonly used as a low-level disinfectant or for environmental cleaning rather than for high-level disinfection of endoscopes. Hydrogen peroxide is typically used as a sterilant rather than a high-level disinfectant.