Test laboratory cleanliness
Based on our years of experience, we see ourselves as experts in cleanliness and cleaning of medical devices.

By cleanliness we mean the absence of chemical and particulate impurities, microorganisms or endotoxins, proteins and blood residues after the manufacturing process or after the reprocessing of reusable medical devices.

To do so, we provide our customers with the following services from our company or through qualified cooperation partners:

  • Examination of chemical residues after the manufacturing or cleaning process
  • Examination of particulate residue after the manufacturing or cleaning process according to ISO 14708 (more)
  • Examination of microbial residues and endotoxin residues after the manufacturing or cleaning process
  • Examination of protein and blood residues after reprocessing of medical devices (more)
  • Consulting, execution and planning of cleaning validations
  • Consulting, execution and planning of reprocessing validations according to DIN EN ISO 17664

Testing for particulate impurities after the manufacturing or cleaning process according to ISO 14708

In addition to the microbiological and chemical cleanliness of medical devices, their particulate purity plays an increasingly important role.

Particulate impurities on a medical device can lead to rejecting reactions of the body and endanger patient safety.

We carry out testing in accordance with ISO 14708 or customer specifications. This standard applies to active implants and specifies corresponding test procedures and limit values, the specifications of which we also apply to other implants.

The measurement is carried out according to the principle of light blocking by means of a particle measuring device on a rinsing extract of the medical device. The results can be provided in sizes ranging between 2 and 50 µm.

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Cleaning validation

Sterile medical devices are usually manufactured and packaged under cleanroom conditions. This limits the contamination of the products with microorganisms or endotoxins released by them.

While sterilisation-resistant endotoxins pose an immediate risk to patients, it is necessary to limit the bacterial count in order not to endanger the success of the subsequent sterilisation.

In addition to production under cleanroom conditions, disinfectant cleaning of the medical devices prior to final packaging is crucial. By integrating a cleaning step, the cleanroom production conditions can often be limited to the subsequent packaging processes.

Validation is necessary to demonstrate an effective cleaning process. In the course of simulated cleaning with artificially contaminated products, our laboratory can test the effectiveness of cleaning for the removal/inactivation of microorganisms or endotoxins.

In addition, the cleaning process can also be examined for its suitability for removing specific production residues. This may be done through chemical analysis and/or cytotoxicity testing. The goal is to prove whether the presence of toxic residues can be expected after the production process and final cleaning.

Our technical experts will advise you comprehensively on the definition of the cleaning processes for your product, draw up the validation plan together with the selection of the appropriate test soiling and the appropriate detection systems, carry out the cleaning simulation (on site), determine the residual soiling, evaluate the cleaning success and draw up a conclusive validation report.

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Microbial count determination / bioburden determination on medical devices and pharmaceuticals according to ISO 11737 or Ph. Eur. 2.6.12

The term microbial count or bioburden refers to the type and number of detectable bacteria and fungi that are present on a product prior to sterilisation.

To detect these, a sample is either dissolved in a suitable test solution or the microorganisms are rinsed off and then cultivated. The result is traditionally a number of grown colonies, which is why the result is expressed in colony-forming units (CFU).

In order to correctly determine the type and number of micro-organisms, a comprehensive validation of the determination method is necessary.

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Test for bacterial endotoxins and pyrogens according to Ph. Eur. 2.6.14 or 5.1.10, according to ANSI AAMI ST 72 and USP Chapters 85 and 161 and monocyte activation according to Ph. Eur. 2.6.30

BBF Sterilisationsservice GmbH has many years of experience and proven competence in the detection of endotoxins and pyrogens and carries out these tests for you in accordance with the applicable standards and regulations.

Pyrogens are substances which, even in small concentrations, trigger fever reactions, a drop in blood pressure and life-threatening shock in both humans and animals. The most important group of pyrogens are lipopolysaccharides from the cell membrane of gram-negative bacteria, usually referred to as endotoxins, which are released when the microorganisms die or the cell membrane disintegrates. They are very thermally stable and cannot be removed or inactivated by conventional sterilisation processes.

In addition, there are also a number of other pyrogenic substances, e.g. lipoteichoic acid of gram-positive bacteria, viruses, RNA, etc.

For the endotoxin determination the units are indicated in endotoxin units per ml (EU/ml). For the pyrogen determination the amount is indicated in endotoxin-equivalent units per ml (EE/ml). The determined endotoxin content is compared with the applicable limit value or the one specified by the customer.


We offer the following endotoxin and pyrogen determination methods as limit or quantitative tests:

Monocyte activation test for pyrogen or endotoxin determination according to Ph. Eur. 2.6.30

The Monocyte Activation Test (MAT) detects proinflammatory cytokines with high sensitivity, which are released by monocytes in the blood after contact with pyrogenic substances and then trigger the fever reaction. Compared to the rabbit test, the MAT has the advantage that it works with human blood or primary blood cells or with human monocytic cell lines and therefore does not require test animals. For our test, we use qualified peripheral mononuclear blood cells (PBMCs) from at least 4 donors and check the presence of pyrogens through the release of the cytokine Interleukin-6 (IL-6).

In the context of the pyrogen determination it is possible to indicate the pyrogenicity by the amount of endotoxin-equivalent units per ml (EE/ml). Within the monocyte activation test it is possible to investigate the potency and presence of different pyrogens (e.g. lipopolysaccharides, lipoteichoic acid or non-bacterial endotoxins).

According to EU Directive 2010/63/EU on the protection of animals used for scientific purposes, preference should be given to alternative methods over animal testing methods. For example, according to the European Pharmacopoeia, chapter 2.6.8, the rabbit pyrogen test should be explicitly replaced by the monocyte activation test according to Ph. Eur. 2.6.30.

Limulus amebocyte lysate test (LAL) according to Ph. Eur. 2.6.14, ANSI AAMI ST 72 and USP, chapters 86 and 161

Since the majority of pyrogens are due to endotoxins, especially lipopolysaccharides (cell wall components of gram-negative bacteria), the Limulus amebocyte lysate test (=LAL test) was developed for their detection. For this test components from the blood of the horseshoe crab are used which coagulate on contact with lipopolysaccharides. The test is carried out according to the Ph. Eur. 2.6.14 and USP chapter 85 as well as in the field of medical devices according to ANSI AAMI ST 72 and USP chapter 161.

We mainly conduct the test as a limit value test. This means our customer defines his limit value, e.g. 20 EU per product unit and we test dilutions below this limit value to ensure the acceptance criteria. The endotoxin content can optionally be determined quantitatively in our laboratory.

In order to produce lysate, the animals must undergo a risky blood sampling procedure. In addition, the lysate reacts not only to lipopolysaccharides but also to beta-glucans. These are polysaccharides found in the cell walls of plants, bacteria and fungi, such as cellulose or chitin.

That is why biotechnologically produced equivalents have been preferred in recent years. See recombinant factor C test in this context.

Recombinant factor C according to Ph. Eur. 5.1.10

We offer testing for the detection of bacterial endotoxins by means of the Recombinant Factor C test. According to Chapter 5.1.10 of the European Pharmacopoeia, this is an alternative method to the Limulus amebocyte lysate test.

We offer two systems of the Recombinant Factor C test: the typical Recombinant Factor C test and the ELISA (enzyme-linked immunosorbent assay) based test for the elimination of interfering factors in advance. Both test systems offer the option of quantitatively determining the endotoxin amount.

In the case of the Recombinant Factor C test, the decisive enzyme, the so-called Factor C, which can usually be found in the blood of horseshoe crabs, is biotechnologically produced. The pure enzyme eliminates false-positive results, which may result from beta-glucans, for example.



The advantages and disadvantages of the single detection methods are provided in the following table:

Reprocessing validation of medical devices according to ISO 17664

The reprocessing of medical devices can be very extensive, depending on the type of medical device. We consult and plan with our customers and work out the requirements for the validation of reprocessing.

We follow the guidelines of the DGKH, DGSV and AKI for the validation and routine monitoring of mechanical and manual cleaning and thermal disinfection processes for medical devices. In addition, we also have the know-how and methods to meet the requirements of the FDA Recommendations "Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling" of March 2015, such as the use of two quantitative methods to determine residual soilage, end-of-life checks through accumulation studies, validation of extraction conditions, etc.

Take advantage of our expertise right from the drafting of the instructions for use as well as the preparation of the validation plan. Benefit from our know-how in the selection of suitable test soiling and the matching detection systems. We offer advice on defining your device’s areas that are most difficult to clean as well as on the definition of product families and the selection of suitable test samples. We carry out the cleaning simulation on the contaminated samples and determine the residual contamination. We prepare the samples for sterilisation testing by applying suitable test microorganisms, packaging the contaminated test samples and arrange for the necessary sterilisation runs to be carried out. Then we evaluate the samples and the controls by means of sterility testing. We subsequently prepare a comprehensive validation report.

We can offer our customers the following services as part of a reprocessing validation:

  • Validation of partial steps: cleaning, disinfection and sterilisation using protein-blood mixtures or microorganisms
  • validation of manual and machine cleaning
  • determination of the number of permissible reprocessing cycles (service life)
  • accumulation studies (multiple reprocessing)
  • quantitative protein determination by BCA assay
  • quantitative haemoglobin determination
  • qualitative luminol test or amido black detection test
  • validation of extraction conditions to verify residual contamination

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Your contact persons

Should you have any questions about our services, please do not hesitate to contact us.

Herr Dr. Norman Layh
Dr. Norman Layh
Business Development
Herr Dr. Christopher Rösch
Dr. Christopher Rösch
Testing laboratory