New York Tattoo License Practice Test

Which disinfectant kills all viruses and bacteria but not spores?

1. 70% isopropyl alcohol

2. 2% gluteraldehyde

3. 3% hydrogen peroxide

4. Quaternary ammonium compounds

The correct answer is: 2% gluteraldehyde

The correct answer is 2% gluteraldehyde because it is a powerful disinfectant known for its effectiveness in killing all types of viruses and bacteria, with the exception of bacterial spores. Gluteraldehyde works by penetrating cell membranes and disrupting cellular functions, making it a preferred choice in healthcare settings for high-level disinfection. It is often used to disinfect medical equipment, ensuring that it is free from harmful pathogens before reuse. In contrast, while options like 70% isopropyl alcohol and 3% hydrogen peroxide can effectively kill bacteria and viruses, they do not possess the broad-spectrum efficacy necessary for high-level disinfection against all pathogens, especially spores. Quaternary ammonium compounds, although useful for surface disinfection, have limited effectiveness against certain viruses and bacterial spores as well. Thus, 2% gluteraldehyde stands out as the only disinfectant in the choices listed that kills all viruses and bacteria while still being recognized for its inability to eliminate spores.