How much temperature should be maintained during moist heat sterilization?

Question

Question

This question was previously asked in

RRB Pharmacist Exam Paper 2019

Answer 1

Correct Answer: 121°C

Rationale:

Moist heat sterilization is a method used to eliminate all forms of microbial life, including spores, through the application of high-temperature steam under pressure.
The standard temperature for effective moist heat sterilization is 121°C (250°F). At this temperature, steam under pressure can penetrate and kill microorganisms by denaturing their proteins.
This process usually occurs in an autoclave, a specialized device that uses pressurized steam to achieve sterilization. The typical pressure maintained during this process is 15 psi (pounds per square inch), and the standard duration is about 15-20 minutes, depending on the volume and nature of the material being sterilized.
Maintaining the appropriate temperature and pressure is crucial to ensure that all microorganisms, including heat-resistant spores, are effectively eradicated.

Explanation of Other Options:

151°C

Rationale: While 151°C could be used for dry heat sterilization, it is higher than the standard temperature used for moist heat sterilization. Dry heat sterilization operates at higher temperatures and for longer durations to achieve microbial kill, typically around 160-170°C.

91°C

Rationale: A temperature of 91°C is insufficient for effective sterilization. Although it can kill some forms of bacteria and viruses, it is not high enough to ensure the complete destruction of all microorganisms, especially resistant spores.

181°C

Rationale: 181°C is excessively high for moist heat sterilization and is more appropriate for dry heat sterilization. Such a high temperature is not necessary for moist heat processes, which rely on steam and pressure to achieve sterilization at a lower temperature.

Conclusion:

Among the given options, 121°C is the correct temperature for moist heat sterilization. This temperature, combined with high pressure, ensures the effective destruction of all microorganisms, making it the standard for processes carried out in autoclaves.