# What is PNSU?

## What is PNSU?

This probability value is defined as PNSU (Probability of Non Sterile Unit).

### What is the survival time of biological indicator?

Survival time is the exposure time required in order for all BI’s of a defined population to retain viable spores. Kill time is the exposure time required to achieve inactivation of a population of Biological indicators to the extent that the probability of a viable biological indicator being 1 in 10,000.

What are biological indicators for sterilization?

Biological indicators (within a PCD) are often used for routine monitoring, qualification and load monitoring of a steam sterilizer. Biological indicators are designed to demonstrate whether the conditions during a steam (autoclave) cycle were adequate to achieve a defined level of microbial inactivation.

What is D value of biological indicators?

The D-value refers to time taken at a given temperature to reduce the population of exposed microorganisms by 90% or achieve a 1-log reduction. The z-value is the temperature increase required to reduce the d-value by one log.

## What is D and Z value in sterilization?

D values are the time or dose required for a 90% reduction in microbial concentration via a sterilization process. Z values measure the resistance of the microorganism to death by the sterilization source.

### What are the two types of sterility indicators?

The two categories of chemical indicators are single-parameter and multiparameter. A single-parameter chemical indicator provides information about only one sterilization parameter (e.g., time or temperature).

What is F&O value of autoclave?

The F0 value tells us the equivalent amount of sterilization (in minutes) that would have been completed had the load been at 250°F. (As temperature increases, so does sterilization/kill rate.)

What is F&O value in sterilization?

F0 value is used to determine the exposure time of material for sterilization at a particular temperature. F0 value is the time in minute for the specified temperature that gives the same thermal lethality as at 121 °C in one minute.

## What is 12D process?

12D concept refers to thermal processing requirements designed to reduce the probability of survival of the most heat resistant C. botulinum spores to 10-12. This helps to determine the time required at process temperature of 121oC to reduce spores of C.

### What is D and z-value in sterilization?

What is F&O value in autoclave?

How do you calculate F0 in sterilizer?

To calculate the F0 value, average the temperature of each probe during the sterile hold and then average the different temperatures to get one single temperature.