Cowan, David

Construction workers are exposed to fine particulate inhalation hazards during stucco removal. The ultimate goal of this research is to test a new chemical-assisted method that will reduce workers’ exposures to safer levels. To that end, the minimum specimen size must be determined that will replicate this hazardous work environment. Samples of concrete stucco surfacing material (CSSM) of various sizes ranging from 1-in×1-in. to 8-in.×16-in. were applied to masonry blocks. These specimens were tested to determine the minimum size needed to produce 150-mg/m3 (one order of magnitude larger than the OSHA exposure limit of 15-mg/m3) of airborne particulate in a 1-m3 test chamber when removed with a chipping hammer. Testing results revealed that 5-in.× 5-in. specimen size yielded on average 180-mg/m3 of particulates.

Every year millions of construction workers are exposed to dust in levels that create a hazard to them (Fundukian, 2011). Their environment is contaminated by activities such as cutting, chipping, grinding and sanding building materials. The Occupational Safety and Health Administration (OSHA) refers to this general collection of building materials debris and fine particulates as nuisance dust. Some of the particles in nuisance dust possess properties that make them especially hazardous, such as their shape or specific gravity. It has been found by the Center for Disease Control (CDC) that inhalation of quantities of silica dust above the permissible exposure limit (15.0 mg/m3) causes a deterioration of the outside lining of the lung.This research seeks to limit this exposure by a pretreatment process using acid application and then absorbed moisture content that reduces airborne particulate during the removal of cement stucco surfacing materials. Successful pretreatment would allow removal of CSSM from substrates such that the release of airborne particulates does not exceed the permissible exposure limits (PEL) found in the 29 CFR-Table Z-3 for mining applications (15-mg/m3).