The Benefits of Stringent Cleaning Protocols for Microbiological Safety Cabinets (MSCs)

Microbiological Safety Cabinets (MSCs) are a vital part of many research labs, often with multiple users working in the same cabinet over the course of the day, running different tests and/or experiments, meaning that having stringent cleaning protocols for these work horses of the lab is crucial. Incorrect, or ineffective cleaning of a cabinet can potentially lead to cross contamination no matter how careful the users are, creating lost revenue due to downtime of the cabinet and jeopardising test accuracy, product efficacy and product/user safety; it can also lead to costly product recalls or worse. Additionally, improper cleaning methods can also possibly reduce the lifespan of the safety cabinet, thus providing a lower return on investment (ROI).

An area often overlooked in terms of how to care for it, is the stainless steel within your safety cabinet. Stainless steel is not corrosion-proof, it is corrosion-resistant and owes this resistance to a thin, chromium oxide film on the metal's surface. Therefore, cleaning practices and protocols need to have a balance between ensuring that the cabinet is clear of contaminants and maintaining the integrity of the surface.

No cleaning agent is 100% safe of course. If used inappropriately, some cleaning agents are too aggressive and therefore not recommended for use for lab equipment such as safety cabinets and fume hoods. Some examples would be highly oxidative agents, strong acids and highly concentrated salt solutions. Instead, as highly experienced in the airflow equipment field, we would recommend* disinfecting agents based on alcohol (70% ethanol or 70% isopropanol) or alternatively disinfecting agents based on QUATS (quaternary ammonium salts) as detailed below:

Before and after every application:

Clean with 70% ethanol or isopropanol solution. Ensure this covers the worksurface and 10cm of the back wall including plug sockets as these are high touch points, but often missed from general cleaning practices.

If the SOP requires strong solutions such as Virkon to clean the surface then after cleaning, wash thoroughly with pre-treated water ONLY. Water quality should be maintained between 50 Kohms-cm and 1 Megohm-cm (electrical resistivity). Feed water quality outside this range, may lead to surface damage.

At least once a week:

Remove all 4 work surface trays and use a non-abrasive stainless steel polish or mild detergent and non-abrasive cleaning pad to scrub all areas constructed of stainless steel. Be sure to thoroughly rinse the area after cleaning is complete.

Additional protection can be obtained by using Bactiscan or BactiscanPRO (available from EIT International) which can instantly identify whether any unwanted bacterial or biofilm contaminants are still present, using unique UV light technology.

Servicing:

A microbiological safety cabinet should be serviced annually as a minimum, or every 6 months if a key piece of lab equipment that is used regularly. This will ensure that the cabinet airflow and HEPA filters are functioning as per BSEN:12469, making the cabinet and lab compliant for any regulatory audits and product pathway transparency.

Microbiological safety cabinets in containment level 3 or 4 (CL3 /CL4) Laboratories should be tested, validated and decontaminated at least every 6 months, as recommended by Advisory Committee on Dangerous Pathogens (ACDP).

Assessing the integrity of the metallic surfaces is also possible using the MAG3 (available from EIT International) this can highlight pitting or cracks developed as a result from corrosion which could harbour unwanted contaminants. A handheld scanning unit that does not rely on dye penetrant methods this could easily be incorporated into a servicing and maintenance programme.

In conclusion, cleaning your safety cabinet should be as important as the experiments and tests you perform in it. By maintaining it regularly and following stringent cleaning protocols, you can benefit from a number of positive outcomes such as:

• The chance of cross-contamination is reduced
• Compliance to regulatory legislation is easier to achieve
• The cabinet works more efficiently
• The lifespan of your capital equipment is extended, which means lower total cost of ownership and improved return on investment.

To discover more about how to keep your safety cabinets safe and efficient, or to schedule inspections & servicing visit our trusted service provider, Crowthorne Group, via www.crowthornehitec.co.uk. For information on Faster airflow products, click here to contact one of our product specialists.

*Cleaning methods and protocols vary depending on the lab and the method we suggest here is based on our own experience and expertise.