The Limitations of Vacuum Systems in Dust Control
The hazards of silica dust are a hot topic in both construction and general industry as contractors look for ways to limit exposure. Most are turning to either vacuum or water systems to aid in silica dust suppression. Both methods of dust control are cited by OSHA as acceptable engineering controls in certain operations to stay OSHA compliant . But is one method more effective than the other? What is the best method to suppress respirable silica dust?
Here’s the truth: Vacuum systems are highly effective in closed areas, where the point source emission has been identified. Beyond this specific environment, vacuum systems become markedly less effective. In open areas, even with a vacuum directed at the point of dust production, respirable silica dust particles, which are invisible to the naked eye, can make their way past the vacuum and become a threat to workers. Throughout the vacuum process, there is even more potential for silica dust exposure when emptying storage drums where vacuumed dust is collected. These drums need to be emptied regularly for the vacuum to be effective but there is no measure for controlling dust during this process. Vacuums also generate high operating and maintenance costs, including energy, bag replacements, corrosion, and deposition. Along with the high initial cost, these hidden costs add up overtime.1
Water Delivery Systems
If vacuum systems are only effective in very specific circumstances which don’t often occur in either construction or general industry operations, what can be done to limit silica dust exposure? OSHA also recommends water as an appropriate method of dust suppression. Dry sweeping is no longer permitted, and water is specifically recommended for use in milling operations as well. When it comes to concrete sawing, OSHA states that “wet cutting is the most effective method for controlling silica dust generated during sawing.” In tests conducted by OSHA in conjunction with NISOH, operators’ exposures were routinely below .1 micron, and usually below .05 microns. OSHA goes on to state that vacuum dust collection systems are an “alternative” for when wet methods cannot be implemented.2
Even OSHA agrees that water-based suppression is a better choice for adequate silica dust control. But is water truly effective in achieving a work environment free of respirable silica dust? A study by the U.S Department of Health and Human Services at Northeast Asphalt, Inc. in Wisconsin found that in milling operations, water output had to be doubled in order to achieve a respirable silica dust level within OSHA’s acceptable range. Increasing water output to achieve adequate dust control increases operational costs and creates a host of other clean-up issues.
So, what should you do? How can you reduce respirable silica dust which is both invisible and deadly if the effectiveness of vacuums is limited and costly and water is required in huge amounts to be effective? Not to worry, there is a solution!
The Simple Silica Dust Solution
Adding NeSilex to existing water systems reduces the amount of water needed for effective respirable silica dust suppression and offers far superior results than vacuum systems in open areas. NeSilex changes the chemical composition of water to make it a silica dust assassin – quickly targeting respirable silica dust particles and forcing them to the ground without having to increase water output. NeSilex reduces respirable silica dust up to 100% in certain construction activities.
While vacuum and water delivery systems do suppress silica dust, neither is nearly as effective as NeSilex is. To ensure the highest levels of worker safety and protection, choose NeSilex.
1 BetzDearborn, Casey. Benefits of Chemical Dust Control Technologies on the Economics of Copper Leaching Operations. http://herculesenvironmental.net/ResourseFolder/42Benefits_of_Chemical_Dust_Control.pdf. Publishing date not available. Accessed July 30, 2019.
2 Occupational Safety and Health Administration U.S. Department of Labor. Controlling Silica Exposures in Construction. Occupational Safety and Health Administration. https://www.silica-safe.org/pdf/OSHA-Controlling-Silica-Exposure-in-Construction.pdf. Published 2009. Accessed August 5, 2019.