Why must porous items like emery boards never be used on more than one client?

Porous items such as emery boards, buffers, and wooden sticks have absorbent surfaces that trap debris and microorganisms, so they cannot be reliably cleaned and disinfected. Using them on more than one client risks transferring pathogens from person to person. For that reason, porous items are single-use and must be discarded after one client (or given to that client). Only nonporous, cleanable items may be disinfected and reused. This rule is a cornerstone of salon infection control and a frequent exam point.