Dust mask respirators are devices that fit over the nose and mouth to filter out harmful particles, fumes, or smoke. They range from a simple disposable dust mask with minimal filtering abilities to the respirators used by firefighters to provide fresh oxygen and filter out smoke. A dusk mask respirator can be purchased for specific hazards or work environments, and it is important to use the proper mask to gain maximum benefits. Proper fit of the mask is vital to obtaining the necessary protection.
The simplest dust mask respirator is the disposable type available in drug stores. These dust mask respirators provide limited uses because they do not seal tightly over the face, especially for men who wear beards. The disposable masks are capable of filtering out low levels of dust in work areas and some airborne particles associated with illness.
A more effective dust mask respirator is one rated according to the hazardous substance the user wants to avoid. The particulate respirator is available in three classes of efficiency according to its intended use. Specialized dust mask respirators of this type can be used in hospitals to protect against contagious diseases, while another kind can filter paint fumes. Farmers who are exposed to excessive dust and chemical insecticides also find the particulate dust mask respirator helpful.
An industrial dusk mask respirator commonly provides air purifying features through a full mask or half mask device. These masks use cartridges designed to filter out specific harmful gases, solvents, or particles. They are used by people removing asbestos or working with silica. Industrial dust mask cartridges can also protect against pesticides and petroleum hazards.
Another type dust mask respirator employs chemicals that purify the air as it enters the mask. A battery pack is attached to the body that powers a fan, which draws air through a filter. An advantage of this dust mask respirator is its ability to provide a proper fit over the face. Its use is limited, however, by the life of the battery, and the equipment can interfere with movement of the user.
Perhaps the most effective dust mask respirator is the type used by firefighters, called a self-contained breathing apparatus. The user carries a fresh air supply in a tank strapped on his or her back. The tanks can be refilled with oxygen and re-used numerous times; equipment to replenish the tank is routinely found at fire sites. Most fire departments forbid male firefighters from wearing beards because they interfere with the fit of self-contained breathing apparatus. The need for this policy has evoked controversy and has been challenged in various court cases.