1. Water. Water is the most efficient means to control dust from cutting concrete products. Bench saws for blocks and bricks typically have ports on the upper blade guard where water supply lines can be attached. Portable saws may or may not be equipped with water supply ports. If the saw is equipped with a wet cutting capability, the mason needs to pre-plan the work to ensure that water will be available at the location while cutting, and that the connections to the water supply are made. If the saw is not equipped with wet cutting capability, an alternative is to use water supplied by a portable water tank or cart. Two workers may be needed for the task, one to operate the cutting tool, and the other to provide the water supply. Again, the mason must pre-plan the job to ensure that the materials and manpower are available to allow for wet cutting. Some abrasive cutting tools, such as grinders, can be equipped with a self contained pump which collects, filters, and reuses a small amount of water.
2. Respirators. Avoid reliance on respirators alone for protection because they are often ineffectively used and do not provide the level of protection afforded by wet cutting. However, if exposures to crystalline silica cannot be sufficiently reduced by wet cutting or ventilation, masons should wear appropriate respiratory protection. The choice of respirator depends on the level of exposure. Examples of recommended respirator selections are the following:
Typical jobs--block running, erecting scaffolds, mortar mixing;
Typical jobs--dry cut block saws, dry cut portable saws;
Typical jobs-use of grinders prior to tuckpointing.
All respirators, including disposable dust "masks", must be approved by NIOSH (National Institute of Occupational Safety and Health). Additionally, a respiratory protection program must be implemented, to ensure that respirators are used safely. For a model respiratory protection program, see the appendix titled "Respiratory Protection".
3. Training Workers. Before workers begin tasks where they may be exposed to crystalline silica dust, they must be trained so that they understand the hazards of silica dust and how to protect themselves. Tool box training materials, in Spanish and English, are included in the appendix titled "Silica Training".
4. Architectural Specifications. Masons should be aware that architectural specifications for block work often contain the requirement that masonry units be laid in a dry condition. This requirement should not prevent a mason from using a wet cutting saw. Meet with the general contractor to set out work practices for block cutting that will not overexpose the mason to silica dust. When possible, plan the work so that blocks can be wet cut in advance, and sufficiently dried before they are laid. During dry weather, blocks may be laid soon after they are cut; alternatively, during wet weather, they may need to be cut several hours in advance, or may need to be placed in a drying chamber.
5. Web Site Resources
© Georgia Tech Research Corporation, 2012.