Bacteria may be introduced into the workplace through sewage, food waste, water, or insects. Biological hazards from various biological organisms can lead to disease in workers. The outbreak of what has come to be known as Legionnaire's disease is an example of what can result from biological hazards. This disease first surfaced at a convention where numerous participants became sick and soon died. That bacteria has been since named Legionnella.
Ergonomic hazards are conditions that require unnatural postures and unnatural movement.
The human body can endure limited amounts of unnatural postures or motions. However, repeated exposure to such conditions can lead to physical stress and injury. Design of tools, workstations, and jobs can lead to or prevent ergonomic hazards. Other aggravating factors include poor posture, an improperly designed workstation, and job stress. RSIs occur to the muscles, nerves, and tendons of the hands, arms, shoulders, and neck.