American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California. Fairfax, VA: American Industrial Hygiene Association, 2002 Jun; :80
NIOSH conducted a health hazard evaluation in response to a request regarding heat stress concerns at a television glass panel production facility. Workers were stationed at three forming lines, each served by its own furnace producing molten glass. Furnace temperatures can exceed 2100 degrees Fahrenheit (F) and temperatures of the formed glass panels can reach 300-400 degrees F. Environmental temperatures were recorded in work areas using Wet-Bulb Globe Temperature (WBGT) monitors. To assess workers' physical effects, personal monitoring was performed, including continuous monitoring of workers' core body temperature (CBT) and heart rate. Workers' pre- and post- shift weights were recorded. During breaks, workers were interviewed regarding possibly related health symptoms. Recorded WBGT readings reached highs of 94.2 degrees, 95.4 degrees, and 102.8 degrees F in areas of the three forming lines, with average readings of 91.2 degrees, 91.5 degrees, and 98.8 degrees F, respectively. Average CBTs were 99.9 degrees, 100.2 degrees, 98.8 degrees, and 100.1 degrees F for four monitored workers. No monitored workers had a sustained heart rate in excess of the evaluation criteria (180 beats per minute minus the individual's age in years.) Two of five workers monitored exceeded 1.5% loss of body weight during their shift. 82% of interviewed workers reported experiencing dehydration while at work. Other reported symptoms included fatigue, lightheadedness, nausea, and near-syncope. While three workers spent parts of their shifts at or above 100.4 degrees F CBT, a measure the American Conference of Governmental Industrial Hygienists (ACGIH) uses to mark excessive heat strain in medically unselected, unacclimatized workers, none reached 101.3 degrees F, the ACGIH criteria for medically selected, acclimatized workers. Additionally, heart rate monitoring did not reveal excessive rates. Despite the fact that these heat stress criteria were not exceeded, the fact that some workers had significant weight loss over their shift and had reported heat-related health symptoms reveals the need for continued attention, awareness, and measures to prevent potentially serious heat-related effects.
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California