Contrasting disinfection and sterilization

A contrast question wants both sides measured against the same criterion, so name the criterion first: what survives the process. Sterilization destroys or removes all microbial life including bacterial endospores, which are the most resistant form and therefore the benchmark — a process that does not kill spores is not sterilization however effective it is otherwise. Disinfection destroys most pathogenic organisms on inanimate surfaces but does not reliably kill spores, and it is graded by level: high-level disinfection kills all organisms except large numbers of spores, intermediate kills mycobacteria and most viruses, and low-level kills vegetative bacteria and some viruses. Add the third term the pair invites, since it is where marks are often lost: antisepsis is disinfection applied to living tissue, which is why the agents differ — a substance safe on a bench may not be safe on skin, and the question expects you to know the difference.

Give the substances the question asks for, and give them by category rather than as a list. For sterilization: moist heat under pressure in an autoclave, which is the reference standard; dry heat; ethylene oxide for heat-sensitive items; hydrogen peroxide gas plasma; and filtration for heat-labile liquids, which removes rather than kills. For disinfection: glutaraldehyde and ortho-phthalaldehyde at high level; alcohols, chlorine compounds and phenolics at intermediate; quaternary ammonium compounds at low level. Say what determines the choice, since that is what shows understanding rather than recall — the Spaulding classification links the level required to how the item is used, so critical items entering sterile tissue require sterilization, semi-critical items contacting mucous membranes require high-level disinfection, and non-critical items touching intact skin require low. For the second question, take the ten terms from your own course glossary and define each precisely rather than approximately.