Which method boils water under pressure?

• A. Glass bead
• B. UV Sterilisation
• C. Boiling water in a kettle
• D. Autoclave

Answer: (D)

Boiling water under pressure happens when steam is used at high pressure, which raises the boiling temperature above 100°C. An autoclave creates a sealed chamber where steam is generated under significant pressure, typically around 121°C at about 15 psi, so water boils and remains at a higher temperature for effective sterilization. This combination of heat and pressure is what enables rapid and thorough sterilization of instruments. By contrast, boiling in a kettle occurs at atmospheric pressure (about 100°C), UV sterilisation uses ultraviolet light rather than heat or pressure, and a glass bead sterilizer relies on hot beads to sterilize without applying pressure.