Cleanrooms are built to improve and guarantee the quality of your product. Having a cleanroom is one thing, however having a contaminant free cleanroom is another!  There are mainly 3 things that can compromise a cleanroom:

  1. environment (5%) e.g. opening and closing doors, …
  2. production process (15%) e.g. manufacturing equipment, packages, …
  3. personnel (80%) by introducing particles trough skin flakes, yeast and movement, …

In order to reduce these risks, you need to have an efficient cleaning and disinfection program in place. 80% of the particles > 25µm are not removed by the airflow, but require cleaning.

Cleaning is mostly seen as sunk costs, but it is not. Cleaning has to be looked at as a value added process.

These 3 key criteria should be taken in mind to add value to your cleaning process

  1. Know the difference between cleaning and disinfection

Cleaning and disinfection are 2 totally different things. Most importantly cleaning must be performed before the disinfection step. Cleaning agents are used to remove soil (such as dirt, dust, and grease) from a surface. Cleaning agents penetrate the soil and reduce the surface tension to allow its removal. The removal of soil is an important step prior to the application of a disinfectant. If there is still soil residue remaining on the surface, the less effective the disinfection step becomes. A disinfectant is a type of chemical germicide which is capable of eliminating a population of vegetative microorganisms (some disinfectants are sporicidal).

Selecting the most appropriate cleaning and disinfectant agents is critical. You will need to be confident that the agents will work and are appropriate for the type of cleanroom and your cleanroom processes.

When selecting a cleaning agent, take into account that:

  • The cleaning agent is neutral and non-foaming
  • The cleaning agent should be compatible with the disinfectant (residues of the cleaning agents could inactivate the disinfectant)

When selecting a disinfectant, consider that:

  • Two disinfectants should be used in rotation, to be GMP compliant. Many regulatory agencies expect to see 2 different disinfectants in place. Therefore the two agents selected should have different modes of activity. It may be prudent for one of the disinfectants to be sporicidal.
  • The disinfectant should have a wide spectrum of activity (being effective against a wide range of vegetative microorganisms including Gram-negative and Gram-positive bacteria)
  • Most ideally, the disinfectant has a fairly rapid action (a short contact time). The contact time is the time that is required for the disinfectant to destroy a microbial population. The contact time is the period of contact when the surface to which the disinfectant is applied must remain wet.
  • Many sporicidal disinfectants are chlorine based and will damage material like stainless steel unless the residue is wiped away after use.
  1. Understand the types of disinfectants

There are a number of different types of disinfectant with different modes of activity. Disinfectant action against the microbial cell include acting on the cell wall, the cytoplasmic membrane and the cytoplasm. Understanding the distinction between different disinfectants is important when selecting between non-sporicidal and sporicidal disinfectants (the division between non-oxidizing and oxidizing chemicals). Non-oxidizing disinfectants include alcohols, aldehydes, phenolics, and quaternary ammonium compounds. Oxidizing disinfectants include halogens and oxidizing agents like peracetic acid and chlorine dioxide.

Use your environmental monitoring (EM) data when selecting the disinfectants to be sure that your range of viable and nonviable contaminants will be removed.

  1. Use proper cleaning techniques

The cleaning and disinfection techniques are important. If cleaning agents and disinfectants are not used in the correct way, areas will not be cleaned effectively. As a result exaggeratedly high levels of microbial contamination will remain as the disinfectant will not penetrate the layers of dirt. Therefore defined cleaning and disinfection steps needs to be in place, recorded in a protocol or SOP (Standard Operating Procedure), such as:

  • Mopping/wiping with a neutral cleaning agent
  • Ensuring the surface has dried
  • Applying a disinfection step by mopping/wiping
  • Keep the surface wet until the contact time has elapsed
  • Rinsing the disinfectant residue if applicable with WFI or IPA70%

Define the techniques to be used for cleaning and disinfection, to avoid cross contamination, for instance:

  • Determine the order of cleaning (most critical rooms first)
  • Use a double or triple-bucket system
  • First mop the sides, then the rest of the surface using S-technique with overlapping strips
  • Define the number of mops to be used for 1 room or per square meter.

Capture the cleaning and disinfection process into a SOP. Provide documentation records of the cleaning and disinfection steps. Make sure the staff is trained in this SOP. Finally start monitoring the cleaning and disinfection efficiency by setting up an environmental monitoring program. This is assessed by viable microbiological sampling of surfaces using techniques like contact plates and swabs. If the results obtained are not within recommended action levels or limits, this suggests a problem with either: the cleaning and disinfectant agents, the frequency of cleaning or the techniques used. But, if the results are satisfactory, you can have confidence that the cleanroom is indeed “clean” and you added the correct value to your cleaning process.

Do you need help in adding value to your cleanroom cleaning process? Contact TRU cleanroomcleaning

References: Annex 1

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