Occupational Safety and Health Administration (OSHA) SLC Practice Exam

What is the primary method of sterilization for materials that cannot be exposed to moisture?

1. Autoclaving

2. Dry heat

3. Chemical soaking

4. Pasteurization

The correct answer is: Dry heat

The primary method of sterilization for materials that cannot be exposed to moisture is dry heat sterilization. This process involves subjecting materials to high temperatures over a specified period, which effectively eliminates microorganisms through dehydration and denaturation of proteins. Unlike autoclaving, which uses steam under pressure to achieve sterilization, dry heat sterilization relies solely on the application of heat in an environment without moisture. This makes it suitable for items such as powders, oils, and some glassware that may be adversely affected by moisture. In the context of sterilization, dry heat is often used for instruments that are heat-stable and need to avoid contamination from moisture, ensuring that the items remain sterile without the risks associated with water-based methods. Other methods like chemical soaking are often used for materials sensitive to heat but they may leave residues that can be harmful or undesirable. Pasteurization is a process used primarily to reduce the microbial load in liquids and is not effective for sterilization, as it does not achieve the same high temperatures or exposure times required to ensure complete sterility. Thus, dry heat stands out as the most appropriate method under the specified conditions.