People can disperse millions of particles and thousands of microbe-carrying particles from their skin and clothing. It is therefore necessary for personnel working in a cleanroom to change into clothing that minimises this dispersion.

Cleanroom clothing is made from fabrics that do not break up and lint; they therefore disperse the minimum of fibres and particles. Cleanroom clothing also acts as a filter against particles dispersed from the person's skin and their indoor, or factory, clothing.

The type of cleanroom clothing used varies according to the type of cleanroom. In cleanrooms where contamination control is very important, personnel wear clothing that completely envelops them and prevent their contamination being dispersed, i.e. a coverall, hood, facemask, knee-length boots and gloves. In cleanrooms where contamination is not as important, less enveloping clothing such as a smock, cap and shoe covers may be quite sufficient.

Whatever the choice of clothing, garments will have to be donned prior to entering the cleanroom, and they should be put on in such a way that the outside of the clothing is not contaminated.

Some types of cleanroom garments are worn once before being thrown away; others are sent for cleaning and processing after being used once. However, garments are normally used more than once. It may therefore be necessary to devise a storage method to ensure that a minimum of contamination is deposited onto them.