Air purifying respirators use cartridges or canisters constructed of carbon or paper-based filters to remove contaminants or particles from non-IDLH (Immediately Dangerous to Life and Health) environments. Air purifying respirators that rely on the user's inhalation to draw the ambient air over the filters are called negative pressure air purifying respirators. Those that utilize blower to pull the ambient air through the filters and then push it to the user are called positive pressure air purifying respirators. Air-purifying respirators have numerous applications from construction and automotive repair to pharmaceutical and oil production.
