EFHSS Questions and Answers - Question Q00003

I want to put my ophthalmological instruments in a washer disinfector. Can someone advice me on detergents, water and process parameters?

The primary source of information on the reprocessing of reusable medical devices is the manufacturer of the medical device. In line with the essential requirements in the Medical Device Directive of 1993 the manufacturer of a reusable medical device shall provide all necessary information regarding procedures for the cleaning, disinfection, packaging and where appropriate the sterilisation of the device (annex 1 clause 13.6.h.).

Working group 10 of CEN TC204 is currently writting the European standard on "the information to be provided by the manufacturer for the re-processing of re-sterilizable devices. This working group recognized the following information as being essential for the cleaning of a device:

• identification of chemicals
• concentration of process chemicals
• techniques to be used including rinsing
• process temperature(s)
• limits on temperature, concentration, time etc.

All this information shall be provided by the manufacturer to the user of the user of the device.

Adrie de Bruijn

Dear Adrie de Bruijn,

My first concern is not the instrument as well as the safety off the patient. The instrument can be clean, free of patient material, but unsafe because of the residuals off chemicals used.

Vis, R.

Dear René Vis,

Your concern for the safety of the patient is noted. Residues of chemicals used in the cleaning, disinfection and/or sterilisation process should not be present on a medical device at the time use. In my earlier response I gave a list of the information which shall be provided by the manufacturer of a medical device for the propper cleaning of the device. This list includes "techniques to be used, including rinsing". The intention of the rinsing after cleaning is to reduce or even eliminate the residues of the chemicals used during the cleaning process. Similar requirements for instructions on the elimination of process residues after chemical disinfection or sterilisation are also included in the draft standard. The draft standard may be obtained through your national standardisation institute.

Adrie de Bruijn

Dear René Vis

I like to respond to your specific question. The detergent we mostly suggest is an enzymatic product this because of the generosity of the product to instruments. As you are aware an alkaline product is a more agressive detergent. An enzymatic product has a neutral acidity that means you don't need an acid to neutralise. If you look at the paramaters you will see that an enzymmatic product is very sensitive to temperature. The temperature may not be to high otherwise the enzymes will be inactiveded. The dosage temperature is around > 30Celsius. If the temperature is lower the detergent can give foam which is not good for the machine and cleaningproces. The cleaningtemperature is between 45C-55C, it depends which water quality you have in your proces. The best temperature is arround the 52C. Of course good rinsing is very necessary to prevent residue forming on the instruments. I would like to advise you to have a good preclaening before the instruments are cleaned by the washingmachine. I also advice you to have two cold rinsings in your washingmachines to prevent coagulation on the instruments.

Gabriel Valks
Maxxim Medical Europe BV

Washing and disinfecting opthalmic instruments in a washer disinfectors is not so much a problem of selecting the right chemicals. Obviously the chemicals must be tenzide free and no rinsing with "instrument milk" like products or other lubricants should be used. The biggest problem with machine cleaning of delicate instruments is that they mover during the process, thus creating mechanic damage. Any system of fixation will cause cleaning problems on the fixation points.

Jack van Asten

Dear,

In FORUM on the AKI website: www.a-k-i.org you can also find answers on questions about:

• instruments for eye operations, disinfection, cleaning
• ophthalmic instruments, machine reprocessing.

Best regards,
Wim Renders