Why do containers of liquid placed in an autoclave need to remain at least slightly open?

• A. To ensure that the temperature inside the container remains lower than the autoclave chamber.
• B. To allow microorganisms to escape before sterilization begins.
• C. To prevent the liquid from evaporating completely during sterilization.
• D. To allow steam to enter and prevent pressure buildup that could cause the container to explode.

Answer: (D)

Verified step by step guidance

1. Understand the purpose of an autoclave: it sterilizes materials by using high-pressure saturated steam at temperatures typically around 121°C.
2. Recognize that when liquids are heated in a sealed container, pressure can build up inside due to steam formation and expansion of gases.
3. Identify the risk: if the container is completely sealed, pressure inside can increase beyond the container's strength, potentially causing it to explode.
4. Explain why keeping the container slightly open is important: it allows steam to enter and pressure to equalize between the autoclave chamber and the inside of the container.
5. Conclude that this pressure equalization prevents dangerous pressure buildup inside the container, ensuring safe sterilization without explosion.