Sterilisation by the application of pressurised steam is the most widely used method in the pharma industry. As the steam condenses on the surfaces of the load, latent heat is released into the load and any organisms. A large body of research has established the treatment temperatures and durations needed to de-activate these organisms and their spores to acceptably low levels of residual risk.

• Porous Loads including textiles, fine-bore tubing or bagged items and Solid goods such as filling line change parts are reliably sterilised in saturated steam autoclaves.  This versatile process also offers the best controlled method of sterilising assemblies incorporating delicate membrane filters, media in open containers and vial stoppers.
• Aqueous Fluids in closed, fragile glass vessels or deformable containers – plastic bottles, LVPs, blister packs, pre-filled syringes - all use vapour from the enclosed water to sterilise the inside of the container.  High pressures are generated there which need to be counterbalanced by additional pressure on the outside. “Counter-pressure” autoclaves add compressed air to the steam in the chamber to protect the integrity of the container.
• Fluids & freeze-dried products contained in small glass vials or ampoules strong enough to withstand the pressures involved can equally be sterilised in Saturated Steam autoclaves.
• Waste Discard can be sterilised with saturated steam just as standard porous or fluids loads as appropriate.  However, decontamination of Pathogenic Loads demands special safety precautions for operators and technical staff.

Some Special cases:

• Where loads are Thermally Sensitive (e.g. instruments, documents), then it becomes necessary to resort to chemical processes such as Chlorine Dioxide, dry-fogged Peracetic Acid or Vaporised Hydrogen Peroxide (VHP). These strong oxidising agents de-activate biological contamination at the surface, but lack the penetration of thermal methods.
• Loads that can be thermally sterilised but cannot withstand high pressure steam can occasionally be treated in Dry-Heat Ovens. Dry heat needs higher temperatures (typically over 220⁰C) for longer periods (30-90 minutes) to deliver the same lethality. It is more difficult to assure a uniform temperature profile throughout the load.

Finally, it is possible to combine washing and sterilisation in a single process, and even meet the specialised demands of preparing vial stoppers, washing, siliconising, sterilising and drying.