Page 56 - OHS, May 2022

90TH ANNIVERSARY
The Past, Present & Future of
There is a common phrase that gets thrown around from time to time: “It is as easy as breathing.” Breathing can be easy. In fact, it’s an instinctual action that raises and lowers our chests, brings oxygen to our lungs and, in turn, helps our hearts pump blood through our bodies. There are times when breathing can be difficult, however. In these occasions, it is not the action of breathing that makes it hard, it is the air being brought in that can create complications. Let’s discuss the history of respiratory protection.
Earliest Respiratory Research
Researchers and scientists understood from the beginning that breathing contaminated, dirty or toxic air could irritate their respiratory systems. As far back as 23 AD, Roman philosopher Pliny the Elder used loose animal bladder skins to cover his face to protect from toxic dustsfrom crushing materials used for pigmented decorations. Centuries later, Leonardo da Vinci would raise a water-soaked cloth over his mouth and nose to prevent the inhalation of toxic chemicals from paint and plaster.1
Throughout the 17th century, we’d see advancements that would be seen as impressive, but it wasn’t until Bernardo Ramazzini, known as the father of occupational medicine, would describe the importance of respiratory protection as a critical prevention method against the hazards of arsenic, tobacco and silica that the need for adequate protections became evident.2
In 1827, Scottish botanist Robert Brown’s theory—the Brownian movement—would show that the collision of rapidly moving gas molecules causes the random bouncing motion of extremely small particles.3 Once scientists understood the behavior of small particles, they could better set forth their mission to protect against them.
Following some in-depth research on the relation of industrial dust and bacteria to respiratory illnesses and diseases, the English created and patented the Nealy Smoke Mask to protect wearers from contaminated air associated with smoke. This mask used a series of sponges that had been soaked in water and were attached to a neck strap. The wearer could squeeze the bag of water to re- saturate the sponge while also filtering out some of the smoke.4
History Led to
Better Respiratory Protection
Prior to World War I, The U.S. Department of the Interior established the United States Bureau of Mines (USBM), which worked to address the high fatality rates of miners. It was this department that would create the first respirator certification program in the United States, which would lead to the first closed-circuit, self-contained breathing apparatus (SCBA) which operated on compressed oxygen and soda lime scrubber to remove carbon dioxide.
Respiratory Protection
BY SYDNY SHEPARD
Americans began to see new threats emerge, such as warfare gases like chlorine, phosgene and mustard gas. At the time, military equipment did not include protective masks or respirators. This oversight would lead to 1.3 million casualties and approximately 90,000 fatalities—30 percent of all casualties during WWI.5
Additionally, soldiers were traveling all around the world, bringing with them viruses and illnesses that proved to be deadly once spread throughout communities. The U.S. would report its first flu symptoms in March of 1918 and by October, over 195,000 would die. It was a result of this flu and subsequent fatalities that the San Francisco Board of Health recommended the use of face masks in public space. The universal masking led to a decline in flu cases, but only after over 675,000 Americans died from the virus.6
Following WWI, the U.S. saw more tragic events that would lead to stronger respiratory protections. In 1930, construction would begin on a new three-mile tunnel through Gauley Mountain in Summersville, West Virgina. Due to the dry drilling technique used on the project, large amounts of silica dust were thrust into the air and onto the workers each day. Excavation of the Hawk’s Nest Tunnel led to the greatest death toll ever from silicosis in the U.S. The lives of 764 workers were lost due to the exposure and in the years following, many more would succumb to illnesses resulting from their work in the tunnel.7
The Evolution of the Standards
The USBM worked to create standards for future certified respirators. Standards had been created previously for breathing apparatus (1919), gas mask respirators (1929) and hose mask respirators (1927). It was during the Hawk’s Nest Tunnel tragedy that the agency was working on a list of requirements for dust/ fume/mist respirators and even sped up the release of the approval standards in 30 CFR 14, Schedule 21 in 1934 as a result of the high fatality rate. The requirements included:
■ Exhalation valves required but inhalation valves optional
■ Pressure-Tightness Tests to assess the fit
■ Test period defined as 90 minutes rather than three
30-minute test periods
■ Addition of a Lead Dust Test
Revisions to Schedule 21 in 1955 would expand to include the
approval of respirators with single use filters and reusable filters. Among the expansion was the definition of two separate types of respirators: one to protect against pneumoconiosis and another to protect against dusts that were not more toxic than lead. Later, the approvals would stretch to include protection against lead fumes, silica and chromic acid mists.
In 1965, Schedule 21 was revised once more to be Schedule 21B. These changes, according to NIOSH, included an extension of certification of approval to respirators designed to protect
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