Which of the following is NOT a route of exposure?

The correct answer identifies "Insertion" as not being a recognized route of exposure in hazardous materials contexts. Routes of exposure refer to the ways in which a hazardous substance can enter the body and cause potential harm.

Inhalation involves breathing in hazardous materials, which can lead to immediate or systemic health effects depending on the substance involved. Absorption occurs when substances come into contact with the skin and are absorbed into the bloodstream, which is also a common route for many chemicals. Injection is another legitimate route, where materials are directly introduced into the body through punctures or breaks in the skin, often seen with needles.

"Insertion," however, is not typically categorized as a formal route of exposure in hazardous materials literature. It may suggest a vague or non-standard method of exposure that does not fit the established definitions of how hazardous materials affect human health. This means that in the context of hazardous materials response, focusing on the recognized routes of exposure such as inhalation, absorption, and injection is crucial for assessing risks and planning proper mitigation strategies.