Benchtop steam sterilizers

Where it is not practicable to use a SSD, a suitable validated, and properly operated, benchtop steam sterilizer may be used to reprocess reusable medical devices. Benchtop steam sterilizers may find use in dentistry, and where minor surgical procedures are performed in healthcare premises in the community, especially in areas remote from a SSD.

Traditional benchtop steam sterilizers are unsuitable for processing:

• porous products (e.g. drapes, gowns and dressings etc.)
• devices that are hollow or have lumens (either wrapped or unwrapped)
• solid instruments that are wrapped.

and it is important therefore to use sterilizers with an effective forced air removal system for these types of load.

Vacuum benchtop steam sterilizers have become more readily available during the last two years and there is now a wide variety to choose from. They have a pre-sterilization active (vacuum) air removal stage to ensure steam penetration throughout the load. They also have a post-sterilization drying stage, to ensure that load items are dry before the sterilizer door is opened since items that are not dry cannot be considered to be sterile.

'Benchtop steam sterilizers - guidance on purchase, operation and maintenance' DB 2002(06)  provides guidance that may be useful to you if you are considering whether you need a benchtop steam sterilizer (either traditional or vacuum) or if you are an owner, manager or user who already has one.

The performance of vacuum benchtop steam sterilizers differs greatly between makes and models. The presence of a vacuum air removal system does not necessarily mean that the sterilizer will be capable of processing all loads. Consequently great care is needed when choosing a vacuum benchtop steam sterilizer, to ensure that it is suitable for the loads that you intend to process.

After the sterilizer has been purchased, it must be used correctly, and maintained and validated periodically to ensure that it will produce sterilizing conditions consistently. It should be able to be validated and tested periodically according to our Device Bulletin 'The validation and periodic testing of benchtop steam sterilizers' DB 9804, which provides a test protocol for benchtop steam sterilizers which have 'forced air removal' from the sterilizer chamber. A summary is provided in DB2002(06).

For further information on benchtop steam sterilizers please contact:
Alan Hidderley tel: 020 7084 3172  E-mail alan.hidderley@mhra.gsi.gov.uk
or Ian Smith tel: 020 7084 3306 E-mail ian.smith@mhra.gsi.gov.uk

Ten good-practice points for using benchtop steam sterilizers

• Where possible, use a sterile service facility rather than processing locally.
• Do not process wrapped, tubular or textile products in a conventional benchtop steam sterilizer - process them only in a suitable vacuum benchtop steam sterilizer.
• All items must be clean and dry before loading into the sterilizer.Do not overload the sterilizer - the load items might not be sterilized.
• Sterilization performance must be checked frequently (daily - this includes the steam penetration test on vacuum benchtop sterilizers - and weekly by the user; quarterly and annually by a competent test person). This is in addition to routine maintenance and cleaning.
• Drain and clean chamber and reservoir at the end of each day and leave dry. Replenish with sterile water for irrigation from an unopened container.
• Have the sterilizer's pressure system checked for safety. Keep record of all checks and repairs to the pressure system. Do not circumvent safety features. These are legal requirements.
• Keep permanent records of every sterilization cycle.
• Keep written records of all testing and maintenance carried out on every sterilizer. The records should be kept in a logbook.
• Technical advice is available from Registered Authorised Persons (sterilizers), AP(s). Infection Control Nurses can advise on prevention of cross infection. Consult them if you are not sure how to sterilize a piece of equipment.
• Never reprocess single-use devices.

A pdf of these ten points is available for printing.