How User Behaviour Affects Cleanroom Maintenance

Cleanrooms are carefully controlled environments that need special care and attention to keep any risk of contamination as low as possible. While well-designed cleanrooms do a great job of keeping out any dust or particles, the biggest contamination risk comes from the people who work inside the cleanroom. People constantly shed minuscule amounts of dust, droplets, skin particles and bacteria, which has huge implications for cleanroom cleaning practices and schedules. Each instance of someone entering or exiting a cleanroom carries a contamination risk, which is why there are strict limits on who can enter a cleanroom and when. 
 
However, this risk can be managed quite effectively through proper training and adherence to cleanroom procedures. By managing user behaviour, cleanroom managers can significantly reduce the consumption of cleaning materials and the number of maintenance cycles needed.  

Entering and exiting cleanroom

Entering a cleanroom is the single biggest contamination risk, which is why cleanrooms have strict procedures for gowning and gloving in place. These practices are not trivial: any carelessness in prep or gowning can not only ruin any work currently taking place in the cleanroom, but could also lead to extensive downtime if deep cleaning becomes necessary. 
 
A comprehensive cleanroom gowning procedure typically involves three stages, which may be reflected through distinct areas within the gowning area. Each stage must be kept separate to limit contamination.  
 

• Pre-changing stage: Users remove any items that cannot be worn under cleanroom garments, or would cause unnecessary friction on the skin (jewellery, watches, etc)

• Changing stage: Users put on cleanroom apparel and store/retrieve cleanroom supplies

• Entry/exit stage: Users conduct final checks before entering/exiting the cleanroom

 
For best results, employees should have recently showered and be wearing clean clothing with hair covers. Handwashing is a must. Any use of make-up or personal care products that leave residue should be avoided.

Cleaning and maintaining a cleanroom

Regular cleaning schedules need to be closely followed; any delays or interruptions can lead to much bigger clean costs down the line. Cleaning tasks should be divided into daily, weekly and ‘as needed’ schedules. Aside from reducing contamination risks, regular cleaning also minimises the amounts of cleaning agents and consumables used, enables quicker cleaning, and minimises wear and tear on cleaning tools.  

It is important to note that not all cleaning products are created equal. Only deionised and distilled water should be used for mopping and wiping cleanroom surfaces, and all cleaning detergents must be neutral, non-ionic and non-foaming to avoid build-up on surfaces over time¹. Even mopping practices for cleanrooms are different, as floors must be efficiently cleaned without spreading dirty water over cleaned areas. 

It is good practice to bring cleaning equipment like brooms, mops, and cleaning agents into the cleanroom before beginning the cleaning process. This way, once the process is complete, the cleaning staff only needs to exit once, reducing the possibility of contamination. 

Impact of user behaviour on cleanroom costs

User habits have a big influence on cleaning needs, which directly impacts the costs of cleaning materials like wipes, detergents, disinfectants and mops. All staff members and janitorial personnel should be trained on proper gowning procedures, hygiene and sterilisation practices, and general equipment maintenance. Proper gowning procedures not only minimise the risk of contamination, but they also prolong the life of cleanroom apparel, which can add up to considerable cost savings over the life of the cleanroom. 
 
Only trained personnel should be allowed in the cleanroom. The cleanroom itself should also be equipped with appropriate wipes and cleaning materials, so that users can clean up any spills and carry out routine cleaning tasks without needing to exit the space. Having cleaning guides and checklists posted visibly in the room will help users maintain an appropriately clean environment. 
 
Cleanroom users should also be educated on the importance of minimising movement within a cleanroom. Any sudden or extensive movements can cause excessive shedding of skin particles, dust and bacteria, so movements should be slow and deliberate². 
 
Maintaining a clean environment is a costly and labour-intensive task. But proper training, good hygiene practices and the right cleaning goods can go a long way in reducing those costs while ensuring the cleanroom environment stays pristine and the work in the cleanroom carries on without incident. 
 

Get in touch with Thermo Fisher Scientific to discuss how our range of cleanroom products can optimise your cleanroom operations and help ensure your cleanroom environment always stays safe, protected and pristine. 
 

References 

1. ISO 14644-13:2017, Cleanrooms and associated controlled environments — Part 13: Cleaning of surfaces to achieve defined levels of cleanliness in terms of particle and chemical classifications 
2. Study into human particle shedding, Cleanroom Technology, 2011