EFHSS Questions and Answers - Question Q00232

Dear peers

We are seeking information, knowledge and the experiences of people who have worked with the new low temperature steam sterilizer with formaldehyde particularly in connection with the sterlization of opthalmic biom lenses (presently sterilized by EtO)

Looking forward to hearing from the group
Paschal Kent

Update on Low Temperature Sterilization
by Stuart Line
Authorised Person (sterilizers)

Low temperature sterilization has come of age. With the introduction of the Webeco/Matachana 130 LF a more effective and reliable machine is now available. I have tested the sterilizer (reported in ISSM Journal Vol.7, No. 2 Oct-Dec 2002) at 60C and found the sterilizer was able to kill Simicon Bacillus stearothermophilus both in all parts of the chamber, but also down the narrow bore tube of PCDs. The LTSF machine has been in routine use for over 12 months and proved both reliable and efficient. The only problem experienced has been when spore strips were tested in the open chamber, not in contact with a metal or plastic surface. The organisms require a small amount of condensate for the formaldehyde to produce the lethal effect, this is produced by contact with a solid surface. For convenience when testing the machine spore strips were placed in the head piece only of a PCD, wrapped and placed around the chamber.

Experiments have since taken place using the 50C cycle with success. A report on this work will follow shortly.

The safety of the LTSF process has been greatly enhanced by the use of 2% formaldehyde, so many of the toxicity problems have been removed. In addition much work has been carried out by the Webeco team to improve the sterilizer operation. Details of these improvements will be included in my report to be submitted to the ISSM. I now consider the LTSF process has an exciting future due to its increased safety and lower operating temperature.