Which sterilization method requires higher temperatures and longer duration than steam?

The answer is indeed dry heat sterilization. This method is characterized by using elevated temperatures to achieve sterilization, typically ranging from 160°C to 180°C (320°F to 356°F) and requiring a longer exposure time compared to steam sterilization. While steam sterilization typically operates at lower temperatures (around 121°C or 250°F) with shorter cycles of about 15–30 minutes, dry heat sterilization may require temperatures to be maintained for hours, depending on the specified protocol and the materials being sterilized.

The underlying principle of dry heat sterilization involves the transfer of heat through convection to achieve the destruction of microbial life, including spores, which can be particularly resistant. This method is often used for items that can withstand high temperatures and are not sensitive to moisture, such as glassware, metal instruments, and powders.

In contrast, chemical sterilization's effectiveness is based on specific chemicals and does not rely on high temperatures. Filtration sterilization primarily separates microorganisms from solutions through a filter, and radiation sterilization utilizes ionizing radiation to eliminate pathogens, but both do not require the high thermal treatment typical of dry heat sterilization.