What are the four primary routes of exposure to hazardous materials?

• A. Inhalation, ingestion, ocular exposure, dermal contact.
• B. Inhalation, ingestion, injection, inhalation.
• C. Dermal contact, ocular exposure, ingestion, radiation.
• D. Inhalation, dermal contact, ingestion, radiation.

Answer: (A)

Exposure to hazardous materials mainly happens through four routes: inhalation, ingestion, dermal contact, and ocular exposure. Inhalation is the most common because vapors, gases, and aerosols can be breathed into the lungs and potentially enter the bloodstream. Ingestion occurs when contaminants are swallowed, often from touching contaminated surfaces and then putting hands to the mouth or through contaminated food or water. Dermal contact involves the substance entering through the skin, which can cause local irritation or be absorbed systemically, making gloves and protective clothing essential. Ocular exposure happens when splashes or vapors reach the eyes; the eyes are highly sensitive and exposure can cause irritation or burns and may lead to systemic effects if absorption occurs.

Other options introduce routes not considered primary for most hazardous materials, such as injection or radiation, which are not the standard chemical exposure pathways. The four listed routes cover the typical ways hazardous materials can affect the body and guide appropriate protective measures like PPE, hygiene, and decontamination.