Countries who have recently joined the EU will have to review their existing equipment and purchase of new autoclave equipment in relation to current requirements. Tony Collins reports.
Countries who have recently joined the EU will have to review their existing equipment and purchase of new autoclave equipment in relation to current requirements.
Tony Collins reports.
When 10 new countries joined the EU in May2004 the implications were far ranging amongst all areas of industry and activity. One particular aspect, among many, is the highly regulated area of sterilisation within the food manufacturing and process environment using steam autoclaves.
All autoclave users within these countries should review their existing equipment and any new equipment in relation to current EC requirements.
Within the food industry increasing emphasis these days is put on proving that equipment is being used and set up correctly. A modern autoclave should have the facility to give a data print-out with information needed to prove that a cycle has completed and required operating parameters met. Many can transfer information securely to a computer for storage and analysis. At minimum, a thermocouple port should be available to allow a chart recorder to be used.
Ideally a second cable port should be available to allow easy performance testing and calibration of the autoclave as part of external monitoring and approval schemes. This is especially important if end products are to be exported to other EC countries that may require proof that particular standards are met. Many manufacturers take account of this in their designs. Some are expert in the process of testing and give valuable advice and additional features to optimise their equipment’s performance.
Autoclaves are subject to tight regulation of their construction and operation for safety reasons. The energy stored in an autoclave at operating temperatures, even at the relatively low pressures used, is immense. The European Pressure Equipment Directive 97/23EC(PED) covers the design, manufacture and operation of pressure equipment such as autoclaves. Current and future equipment should be reviewed in relation to this.
Consideration should be given to some of the unique risks associated with laboratory autoclaves. For instance, most modern food laboratory autoclaves are fitted with a thermal lock. This is particularly important where liquids in sealable glass containers are autoclaved and it’s fitting is generally required by the PED for autoclaves intended to process these loads. After the sterilising cycle has completed, the autoclave vessel cools more quickly than the bottles inside. Therefore, at temperatures and pressures that look safe from the autoclave controls, the contents of the bottles (especially if accidentally sealed) may still be at pressure. Serious injuries have been caused when the autoclave is opened too early and cooler outside air hits the surface of these pressurised glass bottles causing them to explode. The thermal lock prevents autoclave opening until the load is at a temperature of around 80oC. For other load types an override is usually provided for use by a supervisor.
Another, often overlooked, aspect of autoclave safety is the mode of operation of the safety valve. Generally, the safety valve, once activated, should relieve the pressure from the system, this being the principle hazard. In food laboratory autoclaves however, there is an additional biological hazard. This hazard requires the safety valve to cycle at an elevated temperature, thus controlling the pressure and sterilising the load.
With multiple users consideration should also be given to the exterior hygiene of the autoclave, whose design should minimise areas where material can build up and pose an infection or cross-infection hazard. Some European autoclaves, such as those produced by the UK manufacturer Priorclave Ltd, are even available with anti-bacterial surface treatments to minimise this risk.
In the manufacture of their entire range of laboratory autoclaves Priorclave Ltd fulfil all European directives and are accredited by UKAS United Kingdom Accreditation Service as a calibration laboratory to international standard BSENISO/IEC17025.
Tony Collins is Managing Director of Priorclave Limited, Woolwich, London, England. www.priorclave.co.uk
