I was hoping you might give some advice re. the correct detergent and rinse aid we should be using in our Deko 2000 (Franke) washer/disinfector. About 18 months ago we switched from a product called "Dekomed" to "Regomat 1" (detergent) and "Regomat 4" (rinse aid). Initially we got very good results but over the last year we have been getting what I can only describe as "water stains" which is brown/rust-like in appearance on the surgical instruments after the cycle completes. Also, the chambers of the machines have a chalky film which I cannot eliminate. I have discussed this problem at length with the relevant people involved ie. maintenance and the service engineer, but the problem persists. The engineer maintains that the problem is caused by our poor quality steam which is used to heat the water which causes the filters to become blocked.
I recently sent a sample of the water used in the cleaning/disinfection process to the Public Analyst Lab. to test the hardness and pH which were 72mg/ml and 7.54pH units respectively. Also, I have lately invested in a multi-tiered enzymatic foam spray which we use to pre-treat the bio-burden. This has not made much difference. The "Regomat 1" is an acid liquid cleaner with lime solving and alkali neutralising effects. It contains organic acid and has a density of 1.17 and a ph of 1. "Regomat 4" has a density of 1.05 g/cm3 and a pH of 2.5 and also contains organic acids.
I would appreciate any advice.

Tony Mc Loughlin

Dear,

Surface changes, corrosion and ageing of surgical instruments or machines as you described in your question may have different reasons. These reasons are described in the "Red brochure" from the working group instruments' preparation about "Proper maintenance of instruments" which you can find on the internet site www.a-k-i.org/pdf/red_eng.pdf. In chapter 12 different reasons for layers are described. Photos about problems you can find in the annexe of the "Red brochure". To find out the reason for your special problem we need to analyse the water quality and the layer. Further more it would be interesting to make an analysis of the water used in the cleaning step and in the final rinse.

Generally we recommend using softened water in the cleaning step and demineralised water for the final rinse.

For good cleaning results the "Red brochure" recommends pH-neutral products with or without enzymes as well as alkaline products, but not acidic products. As you explain the cleaner you use at the moment is an acidic product based on organic acids. For the final rinse you use an acidic product as well. If acidic products remain on some materials it can lead to discoloration during the steam sterilization. For this reason it will be preferable to use a pH-neutral rinse aid.

However, according to the draft long prEN ISO 15883 you can ask for tests for the claning efficacy (Annexe B). We can offer an expertise with our cleaner neodisher mediclean in the washer disinfector type Franke Deko D 32 (former Deko 2000).

Best regards,

Markus Kamer
Chemische Fabrik DR. WEIGERT GmbH & Co. KG
Anwendungstechnik neodisher

Mühlenhagen 85
D-20539 Hamburg
Tel. (49) 40 / 789 60 - 151
Fax (49) 40 / 789 60 - 123