How to keep the coronavirus out of the cleanroom - Interview with Dr. Rüdiger Laub

The corona pandemic also poses new challenges for cleanroom operators. How can they protect their employees and keep production running?

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21 April 2020 Cleanrooms

The coronavirus SARS-CoV-2 also poses great challenges for cleanroom operators. Particularly in cleanrooms, it is important that viruses and bacteria cannot transmit via employees or their clothing. But can this really be achieved?  Where are the pitfalls and how can they be countered? Dr. Rüdiger Laub, Head of the Cleanroom- Academy at profi-con, is on hand to provide the following information.

Dr. Laub, is it possible to prevent SARS-CoV-2 from entering the cleanroom?

No - the penetration of viruses into cleanrooms cannot be completely prevented.

However, much can be done to prevent the virus from finding its way into the cleanroom - for example, by wearing appropriate cleanroom clothing and accessories such as goggles, gloves and other protective materials. And of course, making cleanroom users aware by training and instruction. The risk potential is highly dependent on their behaviour. However, even with the utmost caution, there will never be 100% safety. Because the weak point is the cleanroom user. Due to the long incubation period, employees could potentially carry the virus, and thus transmit it while not feeling ill, or perhaps haven't felt any symptoms yet.

Provided that sufficient testing capacity is available, cleanroom personnel could be tested preventively in so-called "critical infrastructures" - for example, in cleanrooms of hospital pharmacies - at very short intervals or if suspicion exists. Basic principle: Early detection - early removal from processes - reducing risk.

Assume that a cleanroom employee has been tested positive but shows no clinical signs of the disease. How should one then act?

Here the answer is quite clear: anyone who has tested positive for the novel coronavirus should be immediately placed in domestic isolation, i.e. quarantine. This is the clear recommendation of the Robert Koch Institute amongst other field experts. All further measures must be laid down in company pandemic plans and discussed with the doctor or relevant health authorities. 

How long will the employee then be absent? Or to put it another way: Under what conditions can an employee who has tested positive resume work?

This decision should also be made by the doctor. Nevertheless, there are of course rules that support the management of one’s return. In the case of "personnel for critical infrastructure" - i.e. personnel in the health and social services sector - work may be resumed at the earliest 14 days after the first symptoms appear, provided the employee has been symptom-free for 48 hours. In these cases, it is assumed that the person concerned has developed immunological defence.

Let's move on to the topic of prevention: What additional protection options do you currently recommend for cleanroom personnel to prevent the coronavirus from being transmitted into the cleanroom?

Basically, the airlock processes, cleanroom clothing, behaviour, as well as robust cleaning and disinfection measures form very effective barriers against the penetration of viruses; however, SARS-CoV-2 is particularly treacherous and demands further measures.  In this exceptional situation, more protection is advisable. I therefore recommend the following supplementary measures to keep the risks to a minimum: As a matter of principle, only one person should currently be in the airlocks leading directly to the production areas.  Another starting point is protective clothing - for example face protection. This should now also apply in the cleanroom classes where this is currently not provided as standard - i.e. also in the GMP cleanliness classes D and C / ISO cleanliness classes ISO 9 to ISO 6. Since the virus can be spread further via the hands, gloves are currently also a must in all cleanrooms - even if it is not provided for the normal protocols for that cleanroom class. Additional protection is provided by cleanroom wipes, which can be used to clean surfaces and other items as required.

The behaviour of the employees themselves is also important. Speaking must be kept to a minimum; it is best not to talk at all and to use alternatives for communication such as memo boards. If an employee has to cough or sneeze, he or she should never remove the face mask, goggles or other protective clothing from the face, but should cover the facial area with several cleanroom wipes. Otherwise, viruses and bacteria will spread unhindered in the cleanroom, which would have to be disinfected immediately. After coughing or sneezing, employees should immediately go to the personnel airlock with their faces still covered. Then, firstly remove cleanroom wipes from the face, dispose of cleanroom wipes, change clothes if necessary and disinfect the hands. Careful hand hygiene is an important measure against the spread of the virus - also in the cleanroom.

It is undisputed that viruses are often passed from hand to hand. But can the virus also enter the cleanroom or manufacturing processes via material?

Basically, yes. Viruses can survive on surfaces for a certain period of time. To minimize this risk, increased protective measures must therefore be established, for example by carrying out additional pre-cleaning and disinfecting surfaces more frequently than usual. In addition, care should be taken to touch only necessary items and surfaces at the time of installation, thus avoiding recontamination.

Assuming that an employee is infected with the novel coronavirus, or if there is a suspicion. What can I do so that in such a case to ensure that the entire production unit is not endangered?

One possible approach is to form two or more teams with non-changing composition. It is important that these teams have no contact with each other. If an employee falls ill or becomes infected, the contact persons are only affected within this team. All other teams, however, can continue to work. It should also be considered that time, supervision and similar factors increase. Accordingly, the employment law regulations must be examined in the context of this strategy, and exceptions must be defined and, if necessary, coordinated.

You are head of the Cleanroom-Academy of profi-con. Classroom training with several persons is currently not possible. What other training possibilities are there?

There are different variants such as training by reading, e-learning or individual instruction. Video conferences also allow training without any physical presence. Especially now it is important to sensitize employees to the risks posed by viruses such as SARS-CoV-2 so that they can adapt their behaviours and interrupt the chain of infection.

Thank you very much for the interview!

Dr. Rüdiger Laub worked in research and development for many years after his scientific studies. As a production manager, he created new concepts for cleanroom systems, supported the qualification of cleanrooms, and has developed and implemented the necessary hygiene programs. Since 2018, he has been head of the Cleanroom Academy.  In addition to training and teaching, Dr. Laub is also responsible for customer consultations and quality management.

Since 2008, profi-con's Cleanroom-Academy has been providing knowledge and expertise on cleanroom behaviour, cleaning and regulatory requirements with permanently employed and experienced trainers. Depending on customer requirements, this can take place in the form of daily sessions at their training centres in Leipzig, Aschaffenburg or Marburg. In-house coaching and training are also provided.