Autoclaving (Moist Heat Sterilization): This is the most effective and widely used method. It involves exposing items to saturated steam under pressure, typically at 121^ C ($250^

Here are the primary methods for inactivating bacterial spores:

• Autoclaving (Moist Heat Sterilization): This is the most effective and widely used method. It involves exposing items to saturated steam under pressure, typically at $121^\circ C$ ($250^\circ F$) for $15-30$ minutes, or $134^\circ C$ ($273^\circ F$) for $3-5$ minutes. The high temperature and moisture denature proteins and destroy spores.
• Dry Heat Sterilization: Used for materials that cannot withstand moist heat (e.g., glassware, powders, oils). It requires higher temperatures and longer exposure times than autoclaving, typically $160-170^\circ C$ ($320-340^\circ F$) for $2-4$ hours.
• Chemical Sterilants (High-Level Disinfectants): Certain chemical agents, when used at appropriate concentrations and contact times, can inactivate spores. Examples include:
  • Glutaraldehyde (e.g., $2\%$ solution for 10 hours)
  • Hydrogen peroxide (e.g., $7.5\%$ to $25\%$ solutions)
  • Peracetic acid (e.g., $0.2\%$ to $0.35\%$ solutions)
  • Chlorine dioxide
• Ionizing Radiation: Gamma rays and electron beams are highly effective for sterilizing heat-sensitive medical devices, pharmaceuticals, and food products. The radiation damages the DNA of spores, preventing their germination and replication.