CWS Cleanrooms and Bollé Safety have spent the last year testing cleanroom goggles’ resistance to sterilisation cycles in order to help with EU GMP Annex 1 guidance that comes into force in 2023. Heike Steinmetz from CWS reviews the findings
With regard to the changes in GMP Annex 1, which will come into force in August 2023, and the importance of wearing autoclavable cleanroom safety goggles in sterile environments, it is now necessary to deal more intensively with this topic. CWS Cleanrooms, as a full-service partner around the cleanroom, has also dealt with this topic in detail and, together with the manufacturer Bollé Safety, carried out an initial validation study over a one-year period. Seven cleanroom goggles were systematically tested for their material resistance and the maximum washing and sterilisation cycles. Here are the results:
Protective goggles are necessary in the cleanroom area. On the one hand, to minimise contamination of products and processes by, for example, human skin flakes, microorganisms, particles and droplets from the facial area. On the other hand, however, they are also needed to protect employees in cleanroom laboratories from chemicals, vapours or splinters, for example. Quality assurance in cleanrooms is always of particular importance. Not only in sterile areas, processes and manufacturing must be carried out carefully and according to validated methods. Thus, addressing this issue is worthwhile for the different cleanroom classes and environments.
CWS Cleanrooms therefore carried out a one-year validation study together with Bollé Safety, in which different cleanroom goggle models were systematically tested
With the publication of Annex 1, the requirements for cleanroom garments in GMP cleanrooms have now changed further. From August 2023, sterile face masks and sterile, autoclavable eye covers, among other things, are stipulated by the "Manufacture of Sterile Medicinal Products" of the EU GMP Guide in defined GMP areas.
When deciding on a specific model, in addition to the longevity of the product, the use of the glasses for many hours a day should also be considered.
For employees, criteria such as wearing comfort, individual adjustment options, ventilation of the glasses and freedom of vision are essential. Furthermore, traceability and complete documentation of the reprocessing cycles must always be guaranteed.
For companies that act responsibly, another aspect also plays an important role: sustainability.
On one hand, because it is a matter of reducing one's own footprint, but on the other hand also because the protection of the environment, climate and resources is playing an increasingly important role for customers and clients. This also raises the question of whether disposable or reusable products should be used for cleanroom safety goggles.
With a view to all these aspects, CWS Cleanrooms therefore carried out a one-year validation study together with Bollé Safety, in which different cleanroom goggle models were systematically tested.
Six autoclavable cleanroom goggles and the COVACLEAN disposable goggles from the Bollé Safety cleanroom series ELITE, COVERALL and SUPERBLAST were tested. All models differ in terms of design, ventilation openings (direct & indirect), materials, coatings and other aspects.
The study was carried out in two steps: first, the visual inspection and material testing by CWS Cleanrooms product and quality management in cooperation with Bollé Safety. Then the laboratory tests according to EN 166 and ISO by an accredited laboratory in France.
The glasses worn by our customers in the cleanroom under real conditions were washed, autoclaved, packed and transported back to the customer at two CWS Cleanrooms locations.
In the first part, the frame, the viewing window, the closure and the headband were visually inspected. The product components were tested to see if they retained their material properties such as shape, feel and colour. The headband was also examined for its elasticity.
The safety glasses were then tested in the laboratory in accordance with EN166 and ISO. The viewing windows of the reusable models were tested for light transmission, scratch resistance, condensation fogging (anti-fog), shock and UV resistance as well as the spherical optical performance (quality of vision).These tested aspects are important because they affect the wearing comfort and safety of the cleanroom safety glasses.While the viewing window is completely clear at 100% light transmission (VLT%), decreasing VLT% causes yellowing. The VLT% should therefore not be less than 74%. For scratch resistance, a luminance factor of < 8% applies. Condensation fogging should be > 8 seconds.
The evaluation of the study confirms that the autoclavable cleanroom safety goggles from Bollé Safety have high material resistance and longevity.
The light transmission, scratch resistance, anti-fog condensation (anti-fog), shock and UV resistance as well as the spherical optical performance (quality of vision) keep their strong performance.The maximum reprocessing cycles achieved, including autoclaving, make it clear that all tested models withstand the washing process of CWS Cleanrooms. Although they have gone through up to 30 preparation and sterilisation processes, they have remained resilient.
The yellowing of the glasses frame observed during the study was acceptable in all cases until the cleanroom safety goggles have completed their life cycle.
The results are also positive in terms of their anti-scratch properties: all tested reusable models passed the scratch resistance test K (resistance to surface damage from fine particles) up to 30 cycles. Even after 30 cycles, the light transmission of the pane reached the same or very similar quality as before the start of the test. The fact that the cleanroom goggles show a strong anti-fog and anti-scratch performance of up to 30 cycles can be attributed to the innovative and resistant PLATINUM (trademarked) coating, which is applied to both sides of the lens.
The yellowing of the glasses frame observed during the study was acceptable in all cases until the cleanroom safety goggles have completed their life cycle
As expected, the disposable protective goggles COVACLEAN have less convincing test results, as this model is particularly suitable for single use in sensitive areas such as pharmacies or operating theatres and thus has less durable material properties and lens coating. The grey headband remained resistant to yellowing for up to 30 cycles, however, the PVC frame had already deformed after 5 cycles and the condition of the frame was no longer satisfactory after 20 cycles.
The test reports from the laboratory show that the light transmission of the lens remains acceptable after 30 cycles, but the scratch resistance K and condensation fogging (anti-fog) are not retained with the disposable model.
The first one-year validation study by CWS Cleanrooms and Bollé Safety clearly shows that companies and laboratories can also rely on cost-saving and environmentally friendly reusable solutions for cleanroom safety goggles.
Which protective goggle models are most suitable depends on the individual requirements and the processes in the cleanrooms. Reusable models have shown strong and convincing performance in terms of longevity and safety. They offer a long life cycle that cannot be replicated by disposable models, as they are designed for single use and sterilisation.
As of August 2022, there is a new version of EU GMP Annex 1 on the manufacture of sterile medicines. In order to be best prepared for the changes in requirements in cleanrooms when this Annex comes into force in August 2023, CWS Cleanrooms will carry out further validation studies.
In this way, CWS Cleanrooms can support companies and institutes in dealing early and comprehensively with the topic and the respective advantages and thus finding the right offer on the market.