Basic Hazards


Routes of Entry


Local vs Systemic



Routes of Entry into the Body

Route of exposure describes the way the chemical enters the body. Chemicals may have serious effects by one route, and minimal effects by another. Hazardous chemicals may enter the body by:

Absorption through the respiratory tract via inhalation.
Absorption through the skin via dermal contact.
Absorption through the digestive tract via ingestion. (Ingestion can occur through eating or smoking with contaminated hands or in contaminated work areas.)
Injection: Introducing the material directly into the bloodstream. (Injection may occur through mechanical injury from "sharps".)

In the laboratory the primary routes of chemical exposure is through inhalation and dermal contact. Working in a laboratory with good general ventilation and using a chemical fume hood can prevent inhalation exposures. Wearing appropriate chemical protective clothing prevents dermal contact. Good hygiene habits, such as regular washing your hands, and using tongs or other tools to pick up sharp objects, will prevent exposure through ingestion or injection.