In-depth survey report: control technology for the ceramic industry at American Olean Tile Company, Jackson, Tennessee, report no. CT-110-25b.
Health hazard control methods were evaluated at American Olean Tile Company (SIC-3253), Jackson, Tennessee in April, 1983. The company employed about 360 workers to produce glazed floor and wall tiles from ball clays, pyrophyllite, and flint. The pyrophyllite came from an area in which the deposits were known to be contaminated with crystalline silica (14808607). Air movement was measured, and personal and area air samples were collected for respirable crystalline silica and total dust. Crushing and grinding operations were completely automated. Grinding and pyrophyllite storage buildings were separated from the main production building. All conveyor systems were troughs or enclosed design, and open material transfer points were equipped with local exhaust ventilation hoods. Exposure control was facilitated by good work and housekeeping practices, equipment maintenance, personal protective equipment, medical and environmental monitoring, and isolation of workers from dust sources. Dust control systems were effective in keeping worker exposures below permissible exposure limits. Average respirable crystalline silica content was 13 percent for dry and 15 percent for wet dust. The authors suggest an average hood face velocity of 100 feet per minute to reduce dry dust emissions from open transfer points, and periodic inspection of ducts from holes and partial blockages.