I. Air-purifying type
The air-purifying class of respirator makes contaminated air breathable by passing it through a filtering element before it is inhaled. The earliest, most primitive forms of these devices weren't much more than bag-like screens placed over the head, or pieces of cloth or sponge covering the nose and mouth. Not until the 19th century did the gas mask as we know it begin to take shape.
Lewis Haslett's "Inhaler or Lung Protector," 1847
Among the early forerunners of the gas mask was a device invented in 1847 by Lewis P. Haslett of Louisville, KY. It allowed breathing through a nose or mouth piece fitted with two one-way clapper valves: one to permit the inhalation of air through a bulb-shaped filter, and the other to vent exhaled air directly into the atmosphere. Similar use of valves became common in later masks. The filter material — wool or other porous substance moistened with water — was suited to keeping out dust or other solid particulates, but would not have been effective against poison gas.
In 1849, Haslett's Lung Protector was granted the first US patent for an air-purifying respirator.
Refs.: US Patent #6529 (1849); Smart (2000).
The Stenhouse gas mask, 1854
In the early 1850s, the Scottish chemist John Stenhouse, who had been investigating the power of various forms of charcoal to capture and hold large volumes of gas, put the science to use in one of the first masks capable of removing toxic gases from incoming air.
The mask's filter, made of powdered charcoal, was held between two dome-shaped layers of wire gauze covering the wearer's nose and mouth. Although crude by modern standards, the invention was practical and effective enough that certain chemical factories in London equipped their workers with it. Charcoal in its "activated" form would eventually become the most widely used filter medium for gas masks.
See "The Velvet-lined Gas Mask of John Stenhouse" (article from Armed Forces Chemical Journal, 1958).
John Tyndall - Fireman's Respirator, 1871
In 1871, the prominent British physicist John Tyndall wrote about his new invention: a "fireman's respirator" that combined the protective features of the Stenhouse mask and other breathing devices. After continued development, he exhibited this early form of gas mask at a meeting of the Royal Society in London in 1874. The July 1875 issue of Manufacturer and Builder described it as follows:
Prof. Tyndall's fireman's hood ... is supplied with a respirator, consisting of a valve chamber and filter-tube about four inches long, screwed on outside, with access to it from the inside by a wooden mouthpiece. The respiratory agency consists of cotton wool saturated with glycerin, lime, and charcoal; the lime absorbs the carbonic acid, (one of the products of combustion,) the glycerin acts on the smoke particles, and the charcoal on the hydro-carbon developed in vapors, and Prof. Tyndall declared that after protecting himself with a hood thus prepared he could go into an atmosphere of the most atrocious character and live for a half an hour where he could not, unprotected, have existed for a single minute.
Refs.: John Tyndall, Fragments of Science (1871); Manufacturer and Builder (July 1875) p.158-9; Davis (1947)
Barton's respirators, c. 1874
Samuel Barton, of London, England, designed a device for the purpose of, according to an 1874 patent, "permitting respiration in places where the atmosphere is charged with noxious gases, or vapors, smoke, or other impurities." It included a rubber-and-metal face cover, head harness, glass eyepieces, rubber-coated hood, and one-way valves for exhalation and inhalation. A metal canister on the front of the mask contained alternating layers of filtering materials: charcoal, lime, and glycerin-soaked cotton wool.
In addition to the canister gas mask, the patent described a simple closed-circuit rebreather in which the user would inhale and exhale through tubes attached to an air reservoir carried on the back. In this alternate configuration, a filter containing lime would remove excess carbon dioxide from the breathing loop.
Refs: US patent #148868 (1874); Barker (1926); Smart (2000)
Neally's Smoke-Excluding Masks, 1877
George Neally's original "Smoke-Excluding Mask," patented in 1877 and marketed to fire departments, featured a tightly-fitting face cover with eyepieces of mica or glass. The user breathed air from rubber tubes connected to a filter carried on the chest.
Another version patented by Neally two years later had a filter mounted directly on the facepiece.
Refs.: (National?) Fireman's Journal, Dec. 8, 1877; US patents #195300 (1877), #212969 (1879); Held (1970)
Cup masks
The late 1800s saw a number of patents for cup-shaped masks like the one pictured, which was designed by Hutson R. Hurd in 1879 to "prevent the admission of poisonous or noxious gases, or particles of dust or other matter, into the throat and lungs." Such masks, vaguely resembling pig's snouts when worn, fit over the mouth and nose and were secured to the head with straps. A check valve on the side or top of the casing allowed the escape of exhaled air. Various inventors added other features, such as removable filters and pneumatic face seals. This type of mask became widespread for industrial use.
The H.S. Cover Company, named after its founder, produced cup-type masks for at least two decades after its establishment in 1894. The company was still alive in the 1970s, at which time it was the oldest respirator manufacturer in the United States.
Refs: Barker (1926); Held (1970); US patents #218976 (1879), #577956 (1897), #610914 (1898), #681622 (1901)
Loeb Respirator, 1891
Bernhard Loeb of Berlin, Germany, had been producing and selling respiratory protective equipment through his own company since the 1870s. The apparatus shown at right, for which Loeb earned several patents in Europe and the USA, was designed to "purify foul or vitiated air ... rendered foul by smoke, dust or noxious gases and vapors." (US patent #533854)
A triple-chambered metal canister, carried on the waist, enclosed a filtering system containing liquid chemicals and several layers of granulated charcoal and porous wadding. A flexible hose tube connected the canister to a mouthpiece through which the wearer could breathe the purified air. An alternate configuration (lower picture) had the canister attached directly to a closed helmet surrounding the head of the wearer.
Users of the equipment in the United States included the Brooklyn (New York) Fire Department.
Refs: US patent #533854 (1895); Held (1970)
Muntz Respirator, 1902
In 1902, Louis Muntz of Winona, Minnesota, invented a basic gas mask with full head covering. A canister projecting from the front of the mask contained ducts, valves, a sponge prefilter, and carbon-based adsorbent.
Refs.: US patent #703948 (1902); Held(1970)
II. Self-contained type
The self-contained class of breathing apparatus carries its own supply of fresh air, rather than filtering the surrounding air. Devices of this sort are advantageous for operations of limited duration, in atmospheres that are either deficient in oxygen or charged with unfilterable or excessively concentrated contaminants.
Lane's "pneumatic Life-preserver," 1850
In 1850, Benjamin Lane of Massachusetts received the first known patent for a respirator with a compressed air supply. Its purpose was to allow one to "enter buildings and vessels filled with smoke or impure air and into sewers, mines, wells, and other places filled with noxious gases or impure air, the person being protected from suffocation arising from such causes."
Refs: US patent #7476 (1850); Smart(2000); Barker(1926)
Fleuss Apparatus, 1878
Known mostly as a manufacturer of diving equipment for much of its early history, Siebe Gorman & Co., Ltd. of England also became a popular manufacturer of land-based breathing apparatus. The first of these (left), developed by Henry Fleuss in the 1870s, consisted of a mask of rubberized fabric covering the whole face, connected via tubes to a breathing bag and compressed oxygen cylinder. Also included was a carbon dioxide absorbent chamber that allowed the same air to be rebreathed a number of times. The equipment proved itself in a series of mine rescue operations in England beginning in 1880.
The Siebe-Gorman company and chief designers Fleuss and Robert Davis made a large and lasting impact on respirator design. The 1905 facepiece and tube shown at right prefigures the design of some World War I masks.
Ref: Davis(1947); various websites.
Vajen-Bader Smoke Protector
The Vajen-Bader Co. produced firemen's respiratory equipment since its founding in 1881. The "Vajen-Bader Patent Smoke Protector" of the 1890s and early 1900s sealed off the wearer's head from the environment and supplied breathable air from a compressed air cylinder on the back of the helmet.
Refs: US patents #456687, 645281, 645286, 645408; Held 1970. Picture courtesy of firemuseumnetwork.org
Draeger apparatus, 1903
The apparatus pictured at left, devised in 1903 by the Dräger company of Germany, operated in a similar way as the Siebe-Gorman self-contained devices. Draeger breathing devices and other safety equipment grew so popular in the mine rescue business that the word "draegerman" eventually became a synonym for an underground rescue worker (Webster's Third New International Dictionary). The company, which still exists today, claims to have manufactured two million protective masks for the German Armed Forces during World War I.
Ref: www.draeger.com
III. Air line type
The third major class of respirator consists of a gas-tight mask or head covering, into which a remote air source pumps in clean air via a hose.
Deane Smoke Helmet, 1823
Charles Anthony Deane in 1823 invented a "smoke helmet" for use in fighting fires. The helmet kept out the bad air, and was fed fresh air through a hose which ran from the back of the helmet to an air pump located outside the smoky area. The invention was later adapted for diving purposes.
Photo courtesy of secret-bottletop.com
Merriman's Smoke Mask, 1892
A Denver fireman named Merriman developed one of the many early variations of the hose mask, and one of the few to be produced in the United States. An elephant-trunk-like tube tapped into an air hose that ran parallel to the water hose.
Ref: Held (1970); picture: Fireman's Herald, Jan 7 1892
Garrett Morgan myth
Perhaps the most common misconception about gas mask history is that it began with a device invented by Garrett A. Morgan. In fact, Morgan's invention (patented in 1914, Nos. 1090936 and 1113675) was less like a modern gas mask than many others that preceded it. It consisted of a hood, to which was attached a long, bifurcated breathing tube that hung almost to the ground (see illustration). Similar smoke protectors with a low-hanging tube had previously been patented by a number of inventors throughout the 19th century. These devices allowed the wearer to draw breath from the cleaner layers of air beneath the rising smoke.
To further protect the wearer against smoke, Garrett Morgan lined the inner surface of the far end of the tube with a layer of sponge. When soaked with water, the spongy lining acted like a nasal mucous membrane, serving to moisten the air and to trap soot or smoke particles before they could be inhaled.
While the sponge offered some extra protection against solid particulates, the hood's defense against gases relied exclusively on the inlet of the inhaling tube being physically positioned away from the gas itself. To avoid inhaling lighter-than-air gases such as ammonia that concentrate near the ceiling, the wearer would let the breathing tube hang to the floor. For situations involving heavier-than-air gases, Morgan suggested that "the mouth of the tube can be elevated above the level of the gas." Perhaps a more appropriate designation for his apparatus would be a "gas snorkel," rather than a true gas mask.
It appears that in later years Morgan modified his design beyond what is specified in his two patents of 1914. A picture in Held's book (reference below) shows a Morgan Safety Hood in which the breathing tube, rather than extending all the way to ground level, terminates in a sac-like structure behind the wearer's thighs. The sac likely held the fresh air supply said to have been included on some of Morgan's later models.
Since the Morgan Safety Hood bore little resemblance to a gas mask as we know it, and true gas masks existed several decades before his invention, it is odd that Morgan would ever be credited as the inventor of the gas mask. That is not to say his invention wasn't useful: In 1916, after a gas explosion in a waterworks tunnel beneath Lake Erie, Morgan and other rescuers wore the apparatus to save trapped workers and recover the bodies of victims.
Did Garrett Morgan's hood become the US gas mask in World War I?
The story that the US Army equipped its troops with Garrett Morgan's mask during World War I is not true. Finding no civilian mask suitable for the rigors of chemical warfare, the Army initially had to borrow gas masks from its British and French allies who, having been in the war longer, had developed superior chemical defense technology. When the US did start producing its own military masks, they were merely copies of the British Small Box Respirator (see a brief history of the WWI US Army mask). Although there are indications that Morgan tried to interest the Allied forces in his equipment, none of the masks officially adopted during the war show the distinctive features (such as the split breathing tube) of the Morgan device.
References
Jeffery K. Smart, "History of the Army's Protective Mask" (U.S. Army Soldier and Biological Chemical Command: Aberdeen Proving Ground, MD, 2000)
Robert H. Davis, Breathing in Irrespirable Atmospheres (London, Saint Catherine Press, 1947), Chapter VI: The evolution of breathing apparatus
Bruce Held, History of Respiratory Protective Devices in the US (Livermore, Calif. : University of California, Lawrence Livermore Laboratory, 1970)
M.E. Barker, "Gas Mask Development" Chemical Warfare, 1926;12(7):pp.11-15
Jeffery K. Smart, "History of Chemical and Biological Warfare: An American Perspective," in Frederick R. Sidell et al., Medical Aspects of Chemical and Biological Warfare (Washington, DC: Office of the Surgeon General, 1997), pp. 9-87
Robert J. T. Joy, "Historical Aspects of Medical Defense Against Chemical Warfare," in Frederick R. Sidell et al., Medical Aspects of Chemical and Biological Warfare (Washington, DC: Office of the Surgeon General, 1997)
Christopher T. Carey, US Chemical and Biological Defense Respirators: an Illustated History (Atglen, Pa.: Schiffer Military/Aviation History, c1998)