Which statement about routes to enter the body is true?

• A. Inhalation
• B. Ingestion
• C. Absorption
• D. All of the above

Answer: (D)

Exposure to hazardous substances can occur through several entry pathways. Inhalation lets vapors, dusts, or aerosols enter the lungs and bloodstream. Ingestion happens when contaminants are swallowed, often via hand-to-mouth contact or contaminated food and drink. Absorption refers to substances passing through the skin or mucous membranes into the body. Because each of these is a valid route of entry, the statement that all of the above is true best captures how exposure can happen. In practice this means controls must address multiple routes—ventilation and monitoring to reduce inhalation exposure, hygiene practices to prevent ingestion, and gloves or skin protection to reduce dermal absorption.