Central Service - Issue 1/2003
A Basic Element of Life
- What's New in Standardisation: Washer-Disinfectors
- Denmark: DKCS Conference Report
- ASHCSP Advances the Central Service/Sterile Processing Profession at 2002 Conference
- A Survey Conducted in the USA Attests to a Definite Opposition to Reprocessing of Single-Use Devices
Measurement and Assessment of Hazardous Substance Load at Workplaces in Gas Sterilisation. Part A: Legal fundamentals including measurement strategy and role of direct-reading measuring methods
(Zentr Steril 2003; 11 (1): 29-40)
Since the promulgation of the Ordinance on Hazardous Substances (GefStoffV) in 1986, the decentralised facilities formerly used for sterilising sterile supplies in Germany have generally been combined in central sterilisation departments. These measures have made it possible - and, indeed, this is mandated by GefStoffV - to transfer the operation of sterilisers, which formerly was a task often carried out by the OR department, to specialist and regularly trained personnel in sterile supply departments.
Because of the stipulations enshrined in GefStoffV and in the associated Technical Regulations on Hazardous Substances, hazardous substances other than the sterilisation gases ethylene oxide and formaldehyde used in the vicinity of sterilisation centres must be measured, their concentration in the respiratory air of personnel measured and the measurement result obtained must be compared with the pertinent limit value. Although this also had been already mandated for the sterilisation gases with the promulgation of GefStoffV in 1986, and even more so with the coming into force of TRGS 513, it was possible to establish by interviewing people taking part in corresponding training courses with a view to obtaining qualification certificates to operate a gas steriliser that in many cases the basic requirements for using hazardous substances and in particular for registration, measurement and assessment of hazardous substances were not being fully implemented. Meanwhile, the formulation of procedural- and substitute-oriented criteria (PSO) for fully automated gas sterilisation with formaldehyde in LTSF processes and for fully automated gas sterilisation with ethylene oxide in TRGS 420 make it possible to obtain an exemption from the monitoring obligation by presenting evidence of compliance with preconditions underlying these PSO criteria. If an exemption has not been granted as per these PSO criteria, workplace analysis must be carried out for the gas sterilisation area in accordance with the steps given in Section III. Workplace measurements must be carried out if appropriate information is not available. The latter also applies when using with other hazardous substances such as alcohols, ketones, etc, in this area. In general, workplace measurement can be performed as per TRGS 402 only by in situ sampling, followed by laboratory analysis. The appointed measuring institute must evaluate the measured values obtained in respect of the existing limit values and set the interval for the next control measurements in respect of the evaluated concentration. If the limit value is exceeded, appropriate measures should be recommended to reduce the existing hazard load.
If the procedure- and substance-oriented criteria have been met for ethylene oxide and/or formaldehyde in a particular case, the validity of the preconditions for these PSO criteria must be reviewed each time the process is changed, or otherwise at least once yearly, and the results documented in accordance with TRGS 420.
If leaks are suspected in the system, direct-reading indicator tubes are suitable for measuring the current concentration of hazardous substances of formaldehyde or ethylene oxide. But as a rule such measurements do not meet the criteria governing workplace measurements as stipulated by TRGS 402.
B. Früh, M. Pfeifer*:
Verification of Cleaning Efficacy in Washer-Disinfectors During Routine Operation
(Zentr Steril 2003; 11 (1): 41-52)
Since it has become known that nothing can be rendered sterile unless it is clean, increasingly more importance is being ascribed to the cleaning step when processing medical devices. There is hardly a scientific congress or a training course dealing with processing whose main focus is not on cleaning. Just as cleaning is becoming more important, so the call for suitable test instruments becomes louder. This is perfectly understandable if one bears in mind that in general cleaning efficacy is verified during routine operation mainly on the basis of visual inspection. This, of course, is not without its problems, and is becoming increasingly more difficult as a result of the rapid growth in complex surgical instruments. The hinged regions of instruments as well as lumened (hollow) devices which do not lend themselves to internal inspection present a particular challenge.
While there is a number of laboratory-based methods - of varying quality - for verification of cleaning efficacy, a common feature of all is that the devices in question cannot be assessed and released at their immediate site of use, i.e. in the CSSD. This naturally restricts the use of such methods.
A further problem relates to the choice of test soil. Ideally, a test soil should be identical to a frequently encountered natural contaminant, or at least evince a similar pattern of behaviour. Blood is the most common type of contaminant found on surgical instruments. Therefore there should be a correlation between the test soil and blood.
With the introduction of Tosi and Tosi-LumCheck users now have at their disposal test methods that meet all the requirements for a control method for verification of cleaning processes: first, the test soil is standardised and it correlates with the most common contaminant, i.e. blood. Second, the process challenge devices (PCDs) simulate, depending on the method, the poorly accessible hinged regions of instruments as well as the lumens of hollow devices. This means that we now have easy test methods whose results can be immediately read for reliable verification of the cleaning efficacy in washer-disinfectors. These should be used as an integral feature of any quality management system systems in the CSSD.
Sterilisation Section of the German Society for Hospital Hygiene (DGKH): Principles of LTSF Sterilisation
Choosing the Right Cycle
Can chemical indicators replace biological ones?
Which Sterilant is the Active Component in a Steam Sterilisation Process? Steam? No, it's water!
Reprocessing Medical Devices - New Regulations for Ensuring Safety and Economic Efficiency
RECOMMENDATIONS BY THE QUALITY TASK GROUP (AK »QUALITÄT«)
Water for Operating Washer-Disinfectors (Part 2)