Sterilisaatio

Sterilisation is a process that renders an object, surface, or substance completely free of viable microorganisms, including bacteria, viruses, and spores. In medical and laboratory contexts, sterilisation ensures the sterility of instruments, implants, and consumables to prevent infection and contamination. The term also refers to permanent methods of contraception that render a person incapable of producing offspring.

Common methods for sterilising equipment include steam sterilisation in autoclaves (saturated steam under pressure, typically 121–134°C), and dry heat sterilisation (hot air at 160–170°C). Chemical sterilants such as glutaraldehyde, ortho-phthalaldehyde, and peracetic acid, hydrogen peroxide plasma, and ethylene oxide gas are used for heat-sensitive items. Radiation methods, including gamma rays and electron beam, also achieve sterilisation. For liquids and other heat‑sensitive materials, sterilisation is often accomplished by filtration through membranes with pore sizes of 0.22 or 0.2 micrometers. Validation relies on biological indicators, such as spore tests, and proper packaging and handling are essential to maintain sterility.

In human medicine, sterilisation refers to permanent contraception: tubal ligation for women and vasectomy for men are among the most common procedures. These aim to prevent fertilisation; reversibility is variable and not guaranteed. Ethical, legal, and social considerations apply, including consent, age, and protections against coercion. Sterilisation is distinct from disinfection, which reduces but does not eliminate all microorganisms, and from asepsis, the practice of keeping environments free from contamination.

In veterinary medicine, sterilisation typically denotes spaying or neutering animals. Practices and regulations vary by country, with ongoing advances in minimally invasive techniques and postoperative care.