Hidden Sources of Contamination in the Cleanroom
The objective of an environmentally controlled cleanroom is to provide a contamination-free space in which to test and/or manufacture contamination-free products. Nonetheless, contamination has a way of unexpectedly occurring without any indication of its origin.
Here are some hidden causes of contamination:
People: Improper cleanroom garments, gowning protocol, insufficient gowning for a particular class or infrequent change out intervals of suites, smocks, or other garments and floor mats. Most airborne particles from people migrate out of their cleanroom garments. To combat this, it is important to use cuff sealing tape around the edges of the garment.
Labels and Tape: Many labels are made from paper and have adhesives that leave behind residue. Tapes often come on cardboard cores. Both cardboard and paper release particulates into the environment and oftentimes adhesives and backings can outgas. Make sure you get your cleanroom tape and labels from a certified cleanroom consumable supplier.
Processing Equipment and Tools: It is imperative that all equipment brought into the cleanroom is examined and cleaned. Since some tools generate gases, volatiles, and solid airborne particulates during use. It is important to evaluate all equipment and devise a plan to minimize the impact it will have on the cleanliness of your environment.
Raw Material and Product: Before any raw material or product is brought into the cleanroom it must be cleaned. The extent of cleaning depends upon the class of cleanroom, the destination of the raw material and the possibility of any cross contamination to other processes.
Cleaning Products: Regular household or industrial cleaning products are not acceptable for cleanroom maintenance. Non-particulating wipes and mops must be used for all cleaning needs. Cleanroom vacuums must have a classification rating equal to or better than the cleanroom it is used in.