Which exposure route is primarily associated with entry via inhalation?

• A. Absorption
• B. Inhalation
• C. Ingestion
• D. Injection

Answer: (B)

Exposure routes describe how hazardous materials get into the body. The one tied directly to breathing in is inhalation. When a substance becomes airborne—whether as a gas, vapor, smoke, or dust—it can be drawn into the lungs and then into the bloodstream. That makes inhalation the primary concern for airborne hazards because it provides a direct and rapid entry point, often more immediate than skin contact, ingestion, or injection. For example, released chlorine gas or solvent vapors are typical inhalation risks, which is why respiratory protection and proper ventilation are central responses. The other routes involve entry through the skin (absorption), the mouth (ingestion), or a puncture that delivers material directly into the body (injection), and they are not the path described by inhalation.