Exposure may occur through the absorption, ingestion, or inhalation of some agent or through direct contact with an object or machine part. Exposure may be acute or chronic. It is acute when the exposure occurs over a short time period. It is chronic when the exposure occurs over a long time period. The existence of a hazard combined with the probability of risk determines the severity of a situation.
Severity is the degree of hazard and the risk associated with the hazard.
In agriculture, dangerous situations exist in many forms at all levels of production. Machinery, chemicals, livestock, and the workplace in general present many hazards. Illness is any abnormal condition or disorder, other than injury, caused by exposure to environmental factors associated with employment. Illnesses may include skin disorders and diseases, diseases of the lungs resulting from exposure to dust, respiratory conditions caused by toxic agents, poisonings, disorders caused by environmental factors, cumulative trauma, and others. An injury is a cut, fracture, sprain, or other type of bodily harm that results from exposure to a hazard.