Which of the following is NOT one of the three primary routes of exposure to hazmat substances?

• A. Inhalation
• B. Dermal contact
• C. Ingestion
• D. Injection

Answer: (D)

Exposure to hazmat substances is primarily through breathing in vapors or aerosols, through the skin, or by accidentally swallowing contaminated material. Inhalation handles airborne releases, dermal contact covers absorption through the skin, and ingestion accounts for material that is swallowed, often via hand-to-mouth transfer after touching contaminated surfaces. Injection—entering the body through puncture wounds or needles—is not one of the standard primary exposure routes in hazmat training. It can occur in specific situations (like needlestick injuries), but it is not considered a primary pathway for typical hazmat releases such as spills or vapors.