The ISO 14655 series defines a cleanroom as;
A space where the number of airborne particles are measured.
An enclosed space constructed in a way to minimise the introduction, generation and retention of particles.
A space where other environmental factors may be measured. (humidity, temperature and pressure)
A cleanroom is an investment to both purchase and maintain. A lot of resources, effort, and time are put in to make sure that there is enough air to dilute any contamination, that the air is of the right quality and that the air flows within the cleanroom in the correct manor to reach the desired ISO standard.
Each cleanroom is classified into 9 categories, with ISO 1 as the cleanest and ISO 9 as the dirtiest. Selecting the right air filters, designing the air flow systems, and ensuring that the clean environment is constructed of suitable materials to maintain the integrity of the cleanroom are all vital.
However, with many employees coming in and out, we humans are usually the biggest threats to the integrity of these cleanrooms. According to experts, up to 80% of contamination is brought into the cleanroom by staff.
Here are some precautionary measures to help lessen the chances of compromising a cleanroom.
Wear Proper Cleanroom Attire
Before entering a cleanroom, you need to wear the proper cleanroom attire. That includes hooded barrier coveralls and gowns, goggles, face masks, gloves, boots, and footwear coverings. The type of materials used in the production of these garments vary depending on the purpose of the cleanroom but must not shed.
The cleanroom design are to decrease the presence of the smallest of particles. Wearing complete coveralls protects your process and equipment from getting contaminated by skin cells, falling hair, and other microscopic particles coming from the operator.
Industry specific protection may also be required. For example the electronics industries might require garments which disperse any electrical static (ESD). Even the smallest amount of static can destroy sensitive components. Electrostatic discharge (ESD) apparel guarantees that your tech is not compromised.
Use Masks & Respirators
It might be suitable for all staff inside the cleanroom to wear a mask or a respirator. Masks are extremely important in keeping the cleanroom sterile. Whenever you exhale, you release moisture and other particles in the air, which compromises the integrity of your cleanroom.
As we have now become all too aware of, masks must be properly fitted if they are to minimise any vapours from leaking.
We need particles from 0.3 micron and up to 5 or maybe 10 when we have cleanroom validation depending on the ISO classification of the rooms
A single hair particle is around 100 micron diameter. Headwear protection such as hair nets, hoods, beard coverings and cleanroom goggles, are used to catch and contain hair and skin particles. It is good practice to have a small mirror in the gowning room so that users can check that all hair has been covered before entering the cleanroom.
Protect Your Feet with Overshoes
Employees must also use protective footwear to stop any dust, grime, or dirt from entering the cleanroom. There are many options to cover your feet. Separate cleanroom dedicated footwear, shoe covers or gowning boots. The correct selection will depend on your classification and your process.
Some industries will also have to consider protecting operators feet from process specific dangers as well as protecting the room.
Thorough Hand Washing
Hands are one of the dirtiest parts of the human body. From the house to the office, your hands will be touching dozens of things that others have also touched — door knobs, elevator buttons, pens, even cash.
Even before the coronavirus pandemic, hand hygiene has always been the first step in cleanroom gowning.
Setting up a hand washing station near your cleanroom entrance is a must. Aside from hand soap and sanitizer, experts also recommend a hand dryer. Bacteria, germs, and viruses stick to wet hands faster. After washing your hands, you can then don your cleanroom gloves.
Regular Wipe down of Surfaces
Cleanrooms have high levels of air changes in order to dilute the number of particles in the air. Together with this, it should be a fundamental part of your standard operating procedure (SOP) to regularly wipe down ALL surfaces, furniture and equipment in the cleanroom.
Cleanrooms require non sheading cleaning materials and equipment that is easy to keep clean. You will see stainless steel mops and buckets as the cleaning equipment itself must also be cleaned after use.
The chemicals used for the wipe down will be specially selected to suit your process. It maybe an IPA or an anti microbial cleaner that you require. If you are in a pharmaceutical industry you may well have to alternate two differing products to avoid the microbes becoming resilient to the cleaning agent.
Establishing Cleanroom Habits
All of these practices must be detailed in your standard operating procedures (SOP) all employees must be trained on these practices and they must be strictly implemented. No employee, regardless of rank, should be an exception to any cleanroom rules. Here are some habits employees must practice inside the cleanroom at all times
Wear Cleanroom attire at all times
Make sure that everyone is wearing your selected PPE. Aside from wearing protective gear, they must also be worn properly. Any ill-fitting protective wear must be replaced.
No Food and Drinks
Bringing food and/or drinks inside the cleanroom will contaminate your cleanroom.
There are two reasons to move slowly in a cleanroom. Number one we shed more particulate when we are moving quickly. And secondly an operator rushing inside a cleanroom will also be creating an airflow, small vortex in their wake. This can pick up particles that had settled on surfaces.
Even if you’re wearing a mask, it’s still recommended to limit conversation until needed inside the cleanroom. Saliva particles among other things are more likely to contaminate your facility.
Do you have any questions on how to maintain your cleanroom’s cleanliness? Give us a call to discuss how!