Decontamination & Sterilisation

Decontamination & Sterilisation I Irradiation Services I Customer Focused Solutions

IHSS provides the very latest in decontamination and sterilisation technology, producing an excellent service to our customers.

Washer disinfectors used in the facilities are of the type 1 two door cabinet and type 2 continuous process varieties and pass directly from the cleaning and decontamination area to the instrument assembly and packing area which is a controlled environment. Automatic detergent dosing equipment is used and the final rinse cycle uses reverse osmosis to ensure no carry over of heavy metals or pyrogens. All cycles are logged to provide traceability. Washer disinfectors and ultrasonic cleaners are subject to planned and reactive maintenance programmes together with weekly and quarterly testing and annual revalidation. Tests are undertaken to check the efficacy of process and results documented.

The Instrument Assembly and Packing (IAP) rooms are positive pressure areas with restricted access, a 10 Pascal pressure differential when compared to adjoining rooms and experience 20 air changes per hour. Filters used in the air handling systems are periodically checked by viewing manometers that measure the resistance of air flow through the filter and which highlight the need for change. This, together with the requirement for staff to wear non linting clean room clothing reduces the risk of adventitious contamination. Air particle counting and microbiological slit sampling is undertaken on a regular basis to ensure that clean rooms meet specifications. Bio burden studies are also undertaken to ensure that cleaned product is not subsequently compromised by staff handling prior to sterilisation. This assists in reducing microbial counts and contributes to the efficacy of the sterilisation cycle which is based, by common convention, on a theoretical model that states that one organism will survive the steam sterilisation process on the basis of 1:1013.

The IAP room is used to check the functionality and cleanliness of instruments prior to wrapping in approved packaging materials conforming to European Norms. A label is then affixed conforming to the Essential Requirements of the Medical Device Directive 93/42/EEC. Once securely packed and labelled the product can then be transferred to the sterilisers.

Sterilisers are of the pass through double door type. The sterilizing medium is dry saturated steam operating at above atmospheric pressure to maintain a temperature of either 134°C or 121°C for certain equipment that manufacturers recommend to be processed at lower temperature. The sterilisation process takes between 30 and 45 minutes dependent on chamber size, temperature of cycle and whether extended drying is selected. Sterilizers are subject to planned and reactive maintenance programmes together with daily, weekly and quarterly testing and annual revalidation. Once processed a check is made to ensure that cycle parameters conform to Master Temperature Records and the product is allowed to cool prior to being transported back to the customer. All cycle processing data is stored on computers and the code numbers on the label enable traceability to a particular sterilisation or washer disinfector cycle.