The specific contaminant for which the respirator is approved will be written on the cartridge filter or instructions with the respirator. For farming activities, always use a respirator with a PF rating of 10 or above. Dust that slips through a poor seal goes directly to the lungs. Respirators are available in various sizes and designs to fit most faces. Eyeglasses, clothing, and facial hair such as beards or sideburns, can interfere with the seal.
Respirators can be either disposable or non-disposable.
Disposable respirators are inexpensive and can be discarded when dirty or when the job is finished, but they can be relatively expensive if protection is required on a regular basis. A better choice is a durable respirator that can be washed and stored after each use. The wearer of an air- purifying respirator must be in good physical condition. Since air is drawn through a filtering mechanism, breathing becomes more difficult, and can cause stress for people with medical problems, such as heart conditions or respiratory ailments. Always get a physician's approval to wear a respirator.