The Past & Future of Respiratory Protection
The last two and a half years have taught us how important respiratory protection is.
- By Sydny Shepard
- May 01, 2022
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.
As discussed in previous issues of this year’s editions of the magazine, we will be looking back into the history of important topics in the occupational health and safety industry. We’ve covered the history of occupational health and safety itself, the evolution of fall protection, the right for workers to know what chemicals they are working with, and now we will discuss the history of respiratory protection.
Earliest Respiratory Research
Researchers and scientists understood from the beginning that breathing was an essential human function. What’s more, they understood how 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 dusts let into the air as a result of crushing down 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.
Throughout the 17th century, we’d see further scientific discoveries and inventions that would, today, be considered respirators. The advancements 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, gypsum, tobacco and silica that the need for adequate protections became evident.
The 18th and 19th centuries would see much development in the field of respiratory health. 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. 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.
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.
As war broke out, 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—about 30 percent of all casualties during WWI.
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.
Following WWI, the United States began to see new breathing devices that would protect Americans from toxic air. In 1930, construction would begin on a new three-mile tunnel through Gauley Mountain in Summersville, West Virgina. Miners and construction workers would need to tunnel through solid rock that contained high amounts of silica. 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. History reports that the tunnel was just a white cloud of silica.
Excavation of the Hawk’s Nest Tunnel led to the greatest death toll ever from silicosis in the United States. Of the 5,000 men that worked on the project, it is estimated that 2,900 worked inside the tunnel and were exposed to high amounts of silica. 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.
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 against dusts, fumes and mists that are significantly more toxic than lead, permit certification of combinations of respirators and a revision of the current tests to determine accuracy and speed of testing.
By the time the OSH Act of 1970 created the formation of the Occupational Safety and Health Administration, it was well known that many workplace materials could cause respiratory illnesses that could be prevented by the use of a respirator. It was at this time that OSHA reprinted the original approval standards, without change of text, in the first standards of protection from the agency.
The regulation was later revised to include certification regulations for fit testing which sparked research on exposure in the workplace leading to simulated workplace protection factors and exposure simulations.
OSHA published its respiratory protection standard, 29 CFR 1910.134 on January 9, 1998. This standard would entirely replace the agency’s original standard promulgated in 1972 and standardize regulations for respirator use in all industries.
Into the New Millenium
The terrorist attacks on Sept. 11, 2001 shined a particularly bright light on respiratory protection issues, especially when it came to first responders. As a result of the attack, personal protective equipment used by first responders became a top priority and a collaborative study between the National Institute of Occupational Safety and Health and the New York City Fire Department’s Bureau of Health Services was launched.
The results of the study showed that many first responders did not have access to adequate respiratory protection during the first week of the rescue/recovery mission following 9/11. Further research would show that the rate of respiratory illness was high due to a lack in use of respiratory protection, with many responders later developing forms of respiratory illnesses or diseases, such as lung cancer. In addition, the study found that an alarming amount of first responders were not wearing any protection at all at Ground Zero.
Following the events and research of 9/11, NIOSH would go on to publish its “Interim Guidance on the Use of Chemical, Biological, Radiological, and Nuclear (CBRN) Full Facepiece, Air-Purifying Respirators/Gas Masks Certified under 42 CFR Part 84” in 2005. NIOSH would also develop three CBRN standards for SCBAs, full-facepiece and air-purifying respirators in emergency incidents of terrorism.
In 2015, the American National Standard Institute (ANSI) updated its standard Z88.2 for respiratory protection. The Z88 Committee established the standard in 1969, but later revised it in 1989 and 1992. According to the standard, the Z88.2 standard “sets forth minimally accepted practices for occupational respirator use; provides information and guidance on the proper selection, use and maintenance of respirators, and contains requirements for establishing, implementing and evaluating respirator programs. The standard covers the use of respirators to protect persons against the inhalation of harmful air contaminants and against oxygen-deficient atmospheres in the workplace.”
Looking to the Future
Nearly every American and even citizen of this globe now understand the critical need for respirators following the SARS-CoV-2 pandemic. As the Covid-19 cases rose, so did the global understanding of how respirators could help to curb the transmission of the virus. It is safe to say that without the past researchers and scientists who were so thorough with their research of respiratory illnesses and diseases in the past, we may not have been able to implement universal masking procedures that curbed the spread.
A look back at the history of respiratory research and standards is definitely eye-opening when you consider how much respiratory protection has done for us in the past two and a half years.
This article originally appeared in the May 2022 issue of Occupational Health & Safety.