What should be the temperature in an Autoclave?

Bihar CHO - 2021

Applied Microbiology & Infection control

Easy

Appeared in: Bihar CHO - 2021

Explanation

The standard and most widely used temperature for autoclaving is 121°C.
This temperature is achieved by increasing the pressure to 15 psi, which raises the boiling point of water.
At 121°C, the saturated steam effectively penetrates materials and kills all microorganisms, including highly resistant bacterial spores.
A typical sterilization cycle at this temperature lasts for 15-20 minutes.

Option A: While sterilization can theoretically be achieved at 115°C, it would require a significantly longer exposure time (over 60 minutes) to be effective, making it an inefficient and non-standard cycle.
Option C: This is a duplicate of the first option and is incorrect for the same reasons. 115°C is not a standard temperature for routine autoclaving due to the long cycle time needed for effective sterilization.
Option D: 100°C is the boiling point of water at normal atmospheric pressure. While boiling at this temperature can kill most vegetative bacteria and viruses, it is not sufficient to destroy heat-resistant bacterial spores.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Sterilization principles and autoclave operation as background academic context rather than a clinical decision trigger.
Proper autoclave operation is fundamental to infection control in healthcare settings, preventing healthcare-associated infections (HAIs) by ensuring that surgical instruments and other medical equipment are sterile.
Nurses are responsible for ensuring that items used in patient care have been correctly sterilized. This includes checking sterilization indicators and understanding the principles of autoclave use.
What if? If a biological indicator test for an autoclave load comes back positive, it signifies a sterilization failure. The entire load must be considered non-sterile, recalled if already distributed, and reprocessed. The autoclave must be investigated and serviced before being used again.

How to Approach the Question

First, identify the core of the question, which is asking for the standard temperature of an autoclave.
This is a factual recall question based on microbiology and infection control principles.
Recall the different methods of sterilization. Autoclaving uses moist heat under pressure.
Remember the relationship between pressure and temperature: increasing pressure raises the boiling point of water.
Evaluate the given options. 100°C is boiling, which disinfects but doesn't sterilize. 121°C is the classic temperature for sterilization achieved at 15 psi. 115°C is too low for a standard cycle.
Select the option that matches the standard, most widely accepted parameter for autoclaving.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) pp. 127-129, 126-128