There are many possible sources of contamination of the cleanroom environment. Equipment, structures, and surfaces can generate particles through friction, heat, exhaust, outgassing, and static electricity. Of the many elements of cleanroom operations and processes, humans are the easiest to control, yet contribute the most contamination.

Personal health and hygiene begins at home with daily bathing or showering, shaving, brushing of teeth and hair, and application of silicone-free skin moisturizers to reduce skin flakes. Make-up, hair gels, hair sprays, aromatic after-shave lotions or body lotions are not cleanroom-compatible.

In conjunction with the recommended garment configurations, the appropriate cleanroom fabric, findings, and garment style must be determined. Fabric should be evaluated for small pore size to entrain particles, comfort to the wearer, durability and, if necessary, the presence of cleanroom-compatible, gamma-compatible carbon thread. It is imperative that all operators be trained in proper donning and doffing techniques specific to the cleanroom classification and cleanroom manufacturing operations.

Any activity by the cleanroom operator generates millions of viable and non-viable particles. Consequently, it is imperative to limit talking and actions in the cleanroom to only those required for the manufacture of the product. Running, horseplay, and other non-professional activities are not permitted.