Which of the following requires routine practices and additional precautions?

The correct choice is blood specimens, as they require routine practices and additional precautions due to the potential risk of exposure to infectious diseases. Blood specimens can carry pathogens such as viruses, bacteria, and other infectious agents that pose a significant health risk to laboratory personnel. Therefore, standard precautions, including the use of personal protective equipment (PPE) like gloves and masks, as well as proper handling and disposal protocols, are essential to minimize the risk of transmission.

In a laboratory setting, routine practices involve following established protocols for handling, processing, and disposing of blood samples. Additional precautions might include using safety-engineered devices, such as needle safety devices, and adhering to specific guidelines for the storage and transport of these specimens to prevent leaks and contamination.

The other options pertain to safety but do not inherently emphasize the same level of routine practices and additional precautions related specifically to infectious disease transmission as blood specimens do. While corrosive chemicals and difficult people might also require specific safety measures, they do not have the same implication for routine health risks directly tied to biological materials. Centrifuges require careful operation but are primarily focused on mechanical safety rather than the immediate biological threats associated with blood specimens.