| Popis: |
Aspiration is the entry of liquid or solid materials through the oral or nasal cavity into the trachea and lower respiratory structures. It is initiated at the moment of inspiration, as the causative material lodges at the crossroad of the upper respiratory and digestive tracts. Two major categories of consumer products present a risk of aspiration. They are, on the one hand, petroleum aliphatic hydrocarbons such as kerosene and gasoline, and on the other, lipid and fat-like materials such as mineral and vegetable oils, The hazard of aspiration and its pathological consequences are determined by physical chemical characteristics of a consumer product, and by physiological mechanisms of the respiratory and upper digestive tracts. The former are referred to as intrinsic factors and the latter as extrinsic factors pertaining to the subject at risk. Viscosity and surface tension are the most important intrinsic factors to consider in assessing potential aspiration of consumer products. At the same ti... |
