Respirators

A respirator is a device designed to protect the wearer from inhaling particulate matter, including airborne microrganisms, fumes, vapours, i.e. gases. Respirators range from relatively inexpensive single-use, disposable face masks to more robust reusable models with replaceable cartridges and are used by the military, private industry and the public.

There are two main categories: the air-purifying respirator which forces contaminated air through a filtering element, and the air-supplied respirator in which an alternate supply of fresh air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contaminants.

A respirator is a piece of protective respiratory equipment designed to protect the wearer from inhaling harmful particulate matter (as in dusts, including airborne microrganisms), fumes, vapors, or gases. They range from relatively inexpensive single-use, disposable masks to more robust reusable models with replaceable cartridges, and are used by the military, private industry and the public.

There are two main categories: the air-purifying respirator, which forces contaminated air through a filtering element, and the air-supplied respirator in which fresh air is delivered alternatively. Different techniques are employed to reduce or eliminate noxious airborne contaminants.

There can be confusion over terminology, as some literature and users may refer to a particulate unit as a dust mask or filter, and use the term respirator only to mean a unit that can handle volatile organic compounds solvents.

The history of protective respiratory equipment can be traced back as far as the first century, when Pliny the Elder (circa A.D. 23-79) described using animal bladder skins to protect workers in Roman mines from red lead oxide dust. In the 16th century, Leonardo da Vinci suggested that a finely woven cloth dipped in water could protect sailors from a toxic weapon made of powder that he had designed.

Alexander von Humboldt introduced a primitive respirator in 1799 when he worked as a mining engineer in Prussia. Practically all early respirators consisted of a bag placed completely over the head, fastened around the throat with windows through which the wearer could see. Some were rubber, some were made of rubberized fabric, and still others of impregnated fabric, but in most cases a tank of compressed air or a reservoir of air under slight pressure was carried by the wearer to supply the necessary breathing air. In some devices certain means were provided for the adsorption of carbon dioxide in exhaled air and the rebreathing of the same air many times; in other cases valves allowed exhalation of used air.

...
Wikipedia