How is sterilization typically achieved in a surgical setting?

Sterilization in a surgical setting is most commonly achieved through the application of heat or chemicals. Heat sterilization methods, such as autoclaving, use steam under pressure to kill all forms of microbial life, including bacteria, viruses, and spores. This method is highly effective and is the gold standard for sterilizing surgical instruments. Chemical sterilization involves the use of chemical agents, such as ethylene oxide or hydrogen peroxide gas, to achieve sterilization, particularly for items that cannot withstand high temperatures.

The choice of heat or chemical sterilization is critical because it ensures that surgical instruments and materials are free from any living microorganisms, thus reducing the risk of infection during surgical procedures. Other options, such as applying pressure alone or using cold storage methods, do not effectively sterilize surfaces or instruments and may allow microbes to survive. Similarly, while physical removal of contaminants is important for cleaning, it does not ensure complete sterilization as it may simply reduce the number of organisms without eliminating them completely. Hence, the correct answer encompasses the most reliable methods widely used in surgical settings.