For pre‑vacuum pressure steam sterilizers, the maximum loading capacity shall not exceed 90 % of the chamber volume. Exceeding this limit restricts steam circulation and penetration, which may compromise sterilization efficacy.
For pulsating vacuum pressure steam sterilizers, two conditions apply:
- Upper limit: also 90 % of the chamber volume, for the same reason as above.
- Lower limit: no less than 10 % of the chamber volume. Insufficient load (below 10 %) can cause the "small‑load effect," leading to uneven steam distribution and temperature fluctuations, which also negatively affect sterilization performance.
