Fibrous material used in the dust filter mask physically traps particles. Reusable air-purifying respirators have replaceable filter cartridges. The most common facial types are the half and full face masks. A full face mask covers the nose, mouth and the eyes. If the hazard irritates the skin or eyes, use a full face respirator.
Some cartridges come with pre-filters to use with the respirator cartridge.
Don't forget to use them. If you don't use them, you reduce the amount of protection available to you. Reusable air-purifying respirators are the type commonly used to protect the user from chemical vapors, dusts and mists. Cartridge type air-purifying respirators do not protect from lack of oxygen. Selection and Use Air-purifying respirators offer adequate protection against many common agricultural respiratory hazards.