Drywall Workers Alerted to Dangers of Dust
NIOSH reports that drywall joint compounds are made from many ingredients such as talc, calcite, mica, gypsum, and silica. Some of these substances have been associated with eye, nose, throat, and respiratory tract irritation. Over time, breathing the dust from drywall joint compounds may cause persistent throat and airway irritation, coughing, phlegm production, and breathing difficulties similar to asthma. Smokers or workers with sinus or respiratory conditions may risk even worse health problems. When silica is present, workers may also face an increased risk of silicosis and lung cancer.
A recent NIOSH Health Hazard Evaluation (HHE) found that drywall sanders were exposed to as much as 10 times the permissible exposure limit (PEL) of 15 mg/m3 for total dust set by OSHA. The OSHA PEL for respirable dust, 5 mg/m3, was also exceeded.
Drywall joint compound manufacturers recognize that workers might be exposed to too much dust during drywall sanding. NIOSH studied five manufacturers' material safety data sheets (MSDSs) that warned workers to avoid generating dust and to use respiratory protection when dry sanding. Four of the MSDSs told construction workers to use wet sanding whenever possible, and the fifth said to cut dust exposures by ventilation. However, these guidelines are seldom followed in actual work practice.
Wet sanding is generally avoided because of concerns about drying time and finish texture. Wet sanding is used to protect equipment or furnishings rather than to reduce work exposures. When respiratory protection is worn, it is often used incorrectly with little thought to training, proper selection, or fit.
According to NIOSH, several lightweight sanding systems are now sold to control dust exposure for drywall workers during sanding operations. These systems use portable vacuums to capture and remove the dust before the worker is exposed to it. In 1994, NIOSH studied several of these sanding systems at the International Brotherhood of Painters and Allied Trades (IBPAT) Apprenticeship Training Facility in Seattle, WA, and found that they reduced dust exposures by as much as 97%.
According to the health hazard alert, "vacuum sanding systems can help the sander, subcontractor, general contractor, and building owner... The dramatic reduction in airborne dust exposures results in a much cleaner work area during and after sanding. For workers, the clean working environment is more comfortable; less irritating to eyes, nose, and throat; and less likely to require respiratory protection. For the subcontractor, a comfortable worker is likely to be more productive, be absent less often, and require fewer breaks for fresh air. The savings and reduced regulatory liability given by lower respiratory protection requirements will be passed from the subcontractor to the building owner. Other cost savings will result from a cleaner environment that reduces dirt, cleanup time, and repair or repainting of stained floors and carpets."
Contractors wishing to cut down on dust exposures should consider changing from hand sanding to pole sanding, suggests NIOSH. The agency reports this change is especially important when working overhead. The pole increases the space between the worker and the sanding surface, which in turn reduces the amount of dust close to the workers' nose and mouth.
To obtain free information about controlling this hazard or for information about other occupational health and safety issues, call NIOSH at 1-800-35-NIOSH, or visit NIOSH's web site at http://www.cdc.gov/niosh.