Approaching Pre-Change Zones

Before starting to change into cleanroom clothing, it is best that personnel blow their nose. It is impossible to do this correctly in a cleanroom, and if this is done it will save an unnecessary trip out of the cleanroom. They should also go to the toilet. If it is necessary to come out of the cleanroom to go to the toilet, it is likely to entail changing out and back into cleanroom clothing.

In cleanrooms where outdoor shoes are not removed, or effectively covered, shoe cleaners should be used. Cleanroom shoe cleaners are specially made to retain contamination dispersed from the shoe

Sticky cleanroom mats or flooring are often used in the approach to the change room. These are specially manufactured for use in cleanrooms. There are two general types. One type is laminated from layers of thin adhesive plastic film and the other from a thick resilient adhesive plastic. Both work by removing dirt from the soles of footwear as personnel walk over them . After a while they become soiled. In the case of the plastic film version, the topmost layer is peeled off to expose a fresh layer. In the case of the resilient plastic type the surface is washed.

If a laminated mat is used, shoes should be applied to a mat three times to ensure the removal of practically all of the footwear contamination. If the resilient-type cleanroom flooring is used it can cover a floor surface area large enough to ensure that sufficient steps are placed on it to ensure effective dirt removal. This is a minimum of three per foot i.e. six in all.