Associating Visible Dust Reduction with Respirable Dust Reduction Can be a Deadly Mistake
It is popular belief when washing your hair that more suds equals more cleaning power. However, suds do not actually have correlation to cleaning power. They’re simply a visual indicator to make you feel better about the shampoo’s effectiveness. This is a similar concept to suppressing visible dust on a construction site. Most people think that the disappearance of visible dust indicates that all dust is being controlled, creating a safe environment for workers to operate in. However, this is far from the truth. While conventional engineering controls such as water systems are somewhat effective in suppressing visible dust particles, they fail to adequately control smaller, respirable particles which are invisible to the human eye. In construction environments, respirable particles likely include silica fragments. Inhaling respirable silica dust can lead to a host of lung problems including silicosis.
While it’s common to associate visible dust reduction with respirable dust reduction, this could be a deadly mistake. Let’s look closer to find out why.
The size of a dust particle is measured in micrometers, also called microns (μm). Dust particles start becoming invisible to the naked eye when they are smaller than 50μm. A dust particle is considered respirable when it is 10 μm or smaller. During construction activities such as milling, sweeping, and crushing half of all fugitive dust is small enough to be considered “respirable.” If we only focus on controlling visible dust, we are ignoring half of all airborne dust. Unfortunately, the respirable dust particles pose the most threat to the human body.
The human body provides natural defenses, like mucus and cilia, to filter dust larger than 10 μm. However, respirable dust can penetrate those natural defenses. Respirable silica dust in particular poses a serious threat because its sharp, jagged edges allow it to easily slice into lung tissue and become lodged. Once lodged in the lung, the silica particulate attacks lung tissue and causes serious health problems over time.1
Particulate size is also important in determining how long dust stays airborne and how far it travels. For a dust particle to become airborne it must be smaller than 200 μm. Due to its size and mass, visible dust tends to fall out of the air naturally much more quickly than smaller, respirable particles. In fact, respirable dust can travel long distances away from its point of origin.2 This is particularly concerning in a construction environment as these are typically close in proximity to civilian populations and bystanders. Even when there is no visible dust present, invisible respirable dust can still pose a serious threat.
Safety managers and site foreman may think they are complying with new standards by reducing visual dust on their construction sites; however, this is another misconception. While the EPA does regulate all fugitive dust, the new OSHA regulations concerning silica dust are concerned only with respirable particle sizes. Table 1 which specifies controls for working with and containing crystalline silica do not mention visible dust at all.3 Simply performing an “eye test” to reduce visible dust is not enough. In fact, this type of “eye test” misses the point of reducing respirable dust completely and can lead to fatal results.
NeSilex is the simple silica dust solution. NeSilex can be added to existing water systems to significantly change the properties of water. NeSilex transforms water allowing it to easily and effectively suppress respirable particles specifically hazardous respirable silica dust. Learn more about how NeSilex transforms water into a Silica Dust Suppressing machine here.
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1 Overcoming Silica Dust Particle Size. Bosstek. https://bosstek.com/silica-dust-compliance/silica-particle-size-behavior/. Publish date not available. Accessed July 16, 2019.
2 Silica Monitoring. Public Lab. https://publiclab.org/wiki/silica-monitoring. Publish date not available. Accessed July 17, 2019.
3 Respirable Crystalline Silica. OSHA. https://www.osha.gov/silica/Table1sect1926.1153.pdf. Published March 24, 2016, Accessed July 22, 2019.