Going beyond our previous illustrations on F0 value calculations, provided below an online calculator for F0 value. Enter the details and know the value. Do read our previous articles before using the calculator to get well acquainted with the concept and application of F0 value in moist heat or steam sterilization.
Sometimes, we don’t know the exact z-value for challenged micro-organism. In such situations, the z-value generally assumed as 10 when the moist heat sterilization temperature is between 100 to 130°C. For this calculator, the temperature coefficient value (z-value) considered as 10.
Online Calculator For F0 Value
This is the only calculator available for the F0 value on the web right now. Don’t forget to use only the suggested values for meaningful results.
- T, Average of all temperature probes during sterile hold (Deg. C) – Over a sterile hold duration, calculate the average temperature for each temperature probe and then do the average of all the temperature probes.
- ∆t, Sterile Hold Time (min.) – The time for which system was under sterile hold.
Interpretation of the Calculated F0 value
Once you input the average of all temperature probes over a sterile hold duration in the online calculator, you get the F0 value in minutes. Then, this F0 value shows the equivalency between expected and actual conditions. Let us understand the detailed meaning and significance of the F0 value resulted from this online calculator for F0 value.
F0 value ideally considered for steam sterilization as 30 mins at 121.1°C. As per your above-resulted F0 value, 3 conditions may exist.
- Your F0 value > Ideal F0 value (this condition occurs at temperatures greater than 121.1°C)
- Your F0 value < Ideal F0 value (this condition occurs when temperature is less than 121.1°C)
- Your F0 value = Ideal F0 value
As per condition 1, if the average temperature of the complete system maintained above 121.1°C during 30 minutes of sterile hold duration, the F0 value will be greater than 30 minutes. Resulted F0 value – (minus) 30 = ‘x’ where ‘x’ shows the time exceeded than expected 30 mins. For example, if the calculated value comes out as 40 mins., then ‘x’ becomes 10 mins., meaning effective sterilization has happened 10 mins over 30 mins. Because of a raised temperature.
As per condition 2, if the average temperature of the complete system maintained below 121.1°C during 30 minutes of sterile hold duration, the F0 value will be smaller than 30 minutes. 30 – (minus) Resulted F0 value = ‘y’ where ‘y’ shows the time lacked than expected 30 mins. For example, if the calculated value comes out as 20 mins., then ‘y’ becomes 10 mins., meaning effective sterilization has happened 10 mins less than 30 mins. Because of lowered temperature.
Condition 3 however considered ideal and practically impossible to attain in steam sterilization of the complex equipment systems and autoclaves. This condition, therefore, considered comparative to practical values achieved and used to measure the success of the cycle you perform.
Calculating the F0 value with this approach generally fulfills the requirement of considering the design aspects of the sterilization cycles. Also, helps in developing these cycles based on F0 value itself instead of a time-based approach. However, different practices followed in pharmaceutical industries to implement the F0-based cycles. This includes calculating the individual lethal doses and then testing the F0 value by averaging those lethal doses.
The ultimate aim of doing so is to reduce the micro-organisms to their pre-determined levels. Either way, these methods are bound to give slight variations.
Hope this online calculator for F0 value helped you to perform quick and hassle-free calculations. For more insights on theoretical aspects and calculations, you may visit the previous article or this PDF document.
How did you use this calculator? Did it help you? Which type of systems do you use for your sterilization requirements? Are they time-based or F0-based? Comment below for any clarification.