After rigorous testing funded by the National Institute of Safety and Health, Pullman-Ermator’s dust hoods and shrouds have been proven to reduce silica dust exposure to below OSHA’s proposed limits.
In recent years, the concrete industry has seen an increased emphasis on concrete dust suppression and containment, both for worker safety and job-site cleanliness. OSHA established a Permissible Exposure Limit, (PEL), which is the maximum amount of crystalline silica to which workers may be exposed during an 8-hour work shift (29 CFR 1926.55, 1910.1000. When silica exposure cannot be totally eliminated, OSHA suggests methods in controlling silica exposure when grinding, cutting and coring, by keeping silica dust out of the air through mechanical means such as vacuums and shrouds.
On June 19-20 2013, the Center for Construction Research and Training (CPWR), as part of a NIOSH funded research project, evaluated the performance of Pullman-Ermator S26 HEPA Dust Extractors connected to two hand grinders with metal shrouds, while grinding out masonry mortar joints. This test was carried out as part of an ongoing project aimed at identifying and evaluating effective Local Exhaust Ventilation (LEV) systems for reducing silica exposure during masonry restoration/tuck pointing work. The test showed that the use of the LEV system reduced exposure by approximately 98%, representing a 43-fold reduction.
Even though this was a great reduction in exposure, further testing and improved equipment design were still required to collect the maximum amount of dust.
Existing shrouds could not grab the plume of dust created when a grinder first starts cutting, requiring the vacuum to achieve a higher cubic feet/minute (CFM). To correct the issues revealed in the first test, Pullman-Ermator developed a new hood. Subsequent tests performed by the CPWR in May of 2014 proved the new design to be a great success. When used with Pullman-Ermator’s S13 with a single operator, or the S26 with two operators, dust exposure was reduced an additional three times compared to the first test. The tests demonstrated that proper use of the dust hood and vacuum, along with wearing safety equipment, could reduce silica exposure below the current PEL and the new proposed limits.
Removing old mortar with a hand grinder creates a tremendous amount of dust; one operator can create over 150 pounds of dust in an 8-hour period.
Since much masonry work performed on scaffolding, dust can spread over a large area. Collecting the dust before it settles on the ground, parked cars, and businesses near the jobsite saves time and increases productivity. It also reduces complaints from passing pedestrians, and from fellow workers when dust produced by one blows into the other’s work zone.
While the CPWR tests were performed specifically on mortar grinding, the results are equally valid for other industries where a large amount of silica dust is created using hand tools, including joint cutting and clean out, hand grinding, coating removal and sidewalk restoration.
Pullman-Ermator knows that silica dust is extremely harmful and needs to be captured, and developed dust collection systems that incorporate HEPA dust extractors and a patented dust hood.
Pullman-Ermator’s new, patented (232323) Dust Hood was the missing key to controlling dust on job sites during tuck-pointing. Its ergonomic design propels dust into the shaft. The dust is then is carried away by the vacuum. Replaceable brushes stop the dust “plume” from escaping with the initial cut into wall or joint. It can also be used with five-inch and seven-inch hand grinders, making it ideal for crack chasing, joint cutting and clean out. With its easy “flip up and remove” cover, different blades can be installed quickly without the need to remove the cover completely.
Pullman-Ermator has also developed high efficiency shrouds for floor grinding and coating removal. These five-inch and seven-inch universal fitting shrouds are a necessity for effective dust containment when attached to the proper vacuums. When used with Pullman-Ermator HEPA vacuums, the new five inch and seven inch “Point of Origin” dust shrouds meet EPA RRP requirements. They are adjustable to install easily on most grinders, and the lip can flip up for edge work. The complete kit includes nuts and washers for universal installation, and center rings to install on most grinders. The shrouds capture 99% of airborne dust when used with a proper vacuum, and are made with durable PVC for long life. The 7″ shroud also has a reinforcing metal ring.
The Pullman-Ermator BOOT is a simple solution for chipping hammers and core dills. It solves the problem of dust escaping at the point of origin. The Boot is attached easily to many brands of tools and has a standard fitting for the vacuum hose. It is made from heavy-duty materials for long life.
As more and more regulations become law, dust control through engineering controls is increasingly important. Water cannot efficiently control dust production for grinding, cutting and coring. Slurry clean up is messy and costly when running hand tools.
When shrouds and dust hoods are installed, dust control for safety and job cleanliness is an achievable goal. Pullman-Ermator dust control systems increase productivity and save money by eliminating customer complaints and reducing time spent on cleanup. Collecting dust at its point of origin instead of sweeping it up afterward saves both time and money.
For more information call Pullman-Ermator at 1-855-736-2869, or visit the website at www.ermatorusa.com.