A dental hygienist with an initial limited license may NOT be responsible for which of the following tasks?

A dental hygienist with an initial limited license typically possesses a restricted scope of practice that limits their ability to perform more complex or invasive tasks. Administering local anesthesia is one such task. In Washington State, the administration of local anesthesia generally requires a broader level of training and licensure beyond what is afforded to those holding a limited license.

The other tasks listed—applying prophylactic agents, taking health histories, and performing oral hygiene education—are considered fundamental responsibilities of dental hygienists and fall within the scope of practice allowed for those with an initial limited license. These tasks do not entail the additional training and certification required for the administration of local anesthesia, which is why the limited license prohibits dental hygienists from undertaking that specific responsibility. Thus, the correct answer pertains to the task that exceeds the limitations set for those holding an initial limited license.