Standard precautions apply to all of the following except?

Standard precautions are a set of infection control practices designed to prevent the transmission of diseases that can be spread through blood, body fluids, and certain secretions. They are universally applied to the handling of blood, cerebrospinal fluid, and semen because these bodily substances can potentially carry pathogens.

Blood, as a primary vehicle for transmitting infections, is covered under standard precautions, which include the use of gloves, gowns, and proper disposal methods to protect healthcare personnel and patients. Cerebrospinal fluid is also included, as it can harbor infectious agents and must be handled with care. Semen is similarly encompassed by standard precautions due to the risk of sexually transmitted infections.

Conversely, concentrated acids do not relate to the biological or infectious concerns addressed by standard precautions. While they may present health hazards, such as chemical burns, they are not classified as bodily fluids and do not pose a risk of transmitting infections. Therefore, the correct choice identifies concentrated acids as the exception to standard precautions, as these guidelines do not apply to them.