What level of disinfection kills most microorganisms but not spores?

Intermediate level disinfection is designed to eliminate most types of microorganisms, including bacteria, viruses, and fungi, while being ineffective against bacterial spores. This level of disinfection is particularly useful for items that come into contact with mucous membranes or non-intact skin, where a higher degree of cleanliness is necessary but complete sterility is not required.

This level of disinfection typically uses substances like alcohols, phenols, or chlorine compounds, which can effectively kill a broad spectrum of pathogens. However, because spores are resistant structures that can endure extreme environmental conditions, the intermediate disinfection process does not provide the necessary treatment to eliminate them.

Other levels of disinfection, such as low-level, only target certain bacteria and some viruses, lacking the efficacy needed against higher-risk pathogens. High-level disinfection, on the other hand, is capable of destroying all microorganisms, including spores, making it suitable for items that require sterility, like surgical instruments. The term "complete" does not represent a recognized level of disinfection within the standard classifications, adding confusion to the options provided.