The most common route for hazardous materials to enter the body is through inhalation (breathing them in). This is because many hazardous substances can become airborne as vapors, gases, dust, or fumes, and are easily inhaled into the respiratory system. Once inhaled, these substances may cause health effects ranging from irritation to serious tissue damage and can be absorbed into the bloodstream to affect other organs. Other routes of entry include absorption through the skin or eyes, ingestion (swallowing), and injection (less common). However, inhalation remains the primary and most frequent way people are exposed to hazardous materials, especially in workplace settings where airborne chemicals are prevalent.