American Chemical Society (ACS) Laboratory Safety Practice Test

The term that is not associated with the routes by which chemicals can enter the body is "perception." Inhalation, injection, and absorption are all recognized routes through which chemicals can enter a person’s body, potentially leading to exposure and harmful effects.

Inhalation refers to the breathing in of vapors or particles, which can enter the respiratory system and upon reaching the lungs, can be absorbed into the bloodstream. Injection involves direct entry into the body through needles or other sharp objects, bypassing the skin and allowing chemicals to enter systemic circulation immediately. Absorption refers to the process by which chemicals penetrate through the skin or mucous membranes into the bloodstream.

"Perception," however, does not describe a method of chemical entry into the body; rather, it relates to the ability to interpret or become aware of something, such as the senses. It does not fit in the context of chemical exposure and its routes of entry.