An example of applying ergonomics to prevent carpal tunnel syndrome would be to provide adjustable computer workstations to allow workers to avoid awkward arm and wrist positions. Giving workers more control over how the work gets done reduces stress. PPE is the least effective way to protect workers because it does not eliminate or control the hazards. If the equipment fails, the worker is immediately exposed to the hazard. PPE is needed if there is no other solution, until a better control is installed, or as a supplement to other protective measures.
Ventilation is the best way to control exposure to harmful substances in the air.
Where ventilation is not adequate, respirators are used to avoid breathing and swallowing poisons in the air. There are two main types of respirators, atmosphere supplying and air-purifying . Atmosphere supplying respirators provide workers with air from a safe source. See Figure 4. Supplied-air respirators provide the user with clean air through an air line.