Poor personal cleanliness is not acceptable in a cleanroom. However it is not clear how often personnel should bathe or shower, there being little in the way of scientific investigations into this topic. Clearly a shower would be necessary if someone has just had a haircut and is likely to shed hair clippings. It is known that washing can remove the natural skin oils and, in some individuals, the dispersion of skin and skin bacteria can increase. People with dry skin may wish to use a skin lotion to replace the lost skin oils.

Consideration should be given to what clothing is best worn below cleanroom garments. Clothing made from artificial fibres, such as polyester, are better than those made from wool and cotton, because synthetic fabrics disperse much fewer particles and fibres. Close-woven fabrics are also an advantage, as these are more effective in filtering and controlling the particles and microbe-carrying particles dispersed from the skin. This type of problem will be overcome if personnel are issued with factory undergarments. These should be made from a fabric that does not lint, and it should effectively filter particles dispersed from the person.

Personnel should consider whether applying cosmetics, hair spray, nail varnish, etc. at home is necessary, as these should be removed prior to entering the cleanroom. They should also consider what rings, watches and valuables they will bring to work, as they are likely to be removed and stored.