Final answer:
The item that cannot be disinfected is the emery board, as it is porous and cannot be adequately sanitized, unlike the non-porous items such as glass files, cuticle pushers, and nail rasps.
Step-by-step explanation:
Disinfection is a process that eliminates many or all pathogenic microorganisms, except bacterial spores, on inanimate objects. In nail care and other health-related environments, it's important to disinfect tools to prevent the spread of infections.
However, certain materials are not suitable for disinfection because they are porous and cannot be properly sanitized. An emery board is usually made from a material that is porous, meaning it can absorb liquids and trap microorganisms, making it difficult to disinfect completely.
Unlike glass files, cuticle pushers, and nail rasps which are typically made of non-porous materials such as metal or glass and can withstand the disinfection process, an emery board is designed for one-time use and should be discarded after use with a client.