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Initial Cleanrooms: Unsere Reinraumservices

Decontamination and sterilisation

Cleanroom clothing must be properly treated to ensure the high level of cleanliness required. Timely and professional decontamination is essential for this reason.

Cleanroom textiles are decontaminated in our cleanrooms with ISO categories 5 and/or 7 (ISO 14644-1 certified). The microbiological monitoring of cleanrooms, apparatus, textiles and staff is carried out in accordance with the GMP limit values recommended in Annex 1 (2008) The inspection specification IEST-RP-CC003.4 imposes specific requirements on the textile material, the residual contamination test (just as in ASTM F51-00) and the associated decontamination processes.

Wet decontamination

Nassdekontamination von Reinraumkleidung

Following intensive quality control, the cleanroom clothing is laundered in cleanroom washing machines. These are loaded from the unclean side and unloaded in the cleanroom.

The procedure for the cleaning and decontamination process depends on:

  • Material quality
  • Degree of contamination
  • Duration
  • Temperature


With the addition of clearly defined amounts of water; specific detergent and disinfectant agent as well as treated rinsing water, as specified in accordance with the European Pharmacopoeia. All laundry processes are fully automated and validated. Even during the laundry process, any micro-organisms which may be on the clothing are reduced by 6 log levels. This means that the cleanroom textile is almost "sterile" following the laundry process. However, this has not yet replaced textile sterilisation.


Dry decontamination

In the cleanroom, the decontaminated clothing is taken out of the washing machine and dried in a cleanroom dryer by means of a complex circulation filter system. The key parameters here are the duration and the temperature of the air supplied and extracted (infra-red measurement). The dryers are designed to be particle-free and to handle the material with care, which therefore excludes particle formation.


Particle monitoring

Following the drying and before finishing, we sample the washed batches for germs and particles. The aim here is to provide evidence that the cleanroom clothing contains the lowest possible levels of residual particles and germs.

Using direct contact tests we examine the textiles for residual biological contamination.

Currently two testing methods are used for residual particle measurement in Europe:

  • ASTM F51-00
  • Helmke Drum (IEST-RP-CC003.4)
  • Dekontamination und Sterilisation von Reinraumkleidung

    Helmke Drum (IEST-RP-CC003.4) Measurement methods

    Using air suction, remaining particles are separated at five critical points on the cleanroom clothing, and then registered and counted in a particle measurement device. This method is suited in particular to air-permeable cleanroom fabrics as used, for example, in the pharmaceutical, microelectronics and food industries.

    Helmke Drum (IEST-RP-CC003.4) Measurement methods

    Samples of clothing which have been cleaned are placed in a rotating drum following drying. Particles which are separated through the rotational movement are registered and counted in a particle measurement device. This method is suited to less air-permeable textiles.



    Real time measurement of particle concentration

    Initial Cleanrooms is working intensively on even more precise methods. The aim is not just to record individual items in the dryer at the end of the drying process, but rather the entire washed batch involved. This ongoing in-house quality monitoring via digital measurement in the circulating air is applied via specific sensors during the cooling phase.

    If an analysis reveals that the maximum amount of particles permitted has been exceeded, then an intelligent electronic control system starts the dryer again. In this way more particles are separated through the drying than during the actual laundry process.



    Sterilisation von Reinraumkleidung

    If the decontamination was successful, the cleanroom clothing is also folded, finished and packed in accordance with client requests. As an option, the clothing can also be sterilised.

    Steam sterilisation is carried out at either 121 °C or 134 °C. ETO, gamma and beta sterilisation are also possible if requested.

    With every sterilised delivery, you receive a batch and sterilisation record. It is possible to immediately identify that the cleanroom clothing has been sterilised on the basis of a coloured indicator on each individual pack. In addition to this, the expiry data is printed on every pack. This provides you with the maximum possible safety.