Ammonia Exposures of Blue-line Printers in Houston, Texas

Abstract

Results from 42 industrial hygiene surveys of commercial blue-line printers are reported. The study was initiated in order to evaluate ammonia exposures and associated problems. Workplace ammonia levels ranged from 1 to 40 ppm, with an average concentration of 8.2 ppm. Relationships between the number of employees exposed, number of machines in use, and number of health and safety problems were not statistically significant. A positive relationship was found between the number of health and safety problems and the airborne ammonia levels. A nonlinear positive relationship was found between the age of the blue-line machine and workplace ammonia concentration. Ninety-six percent of the blue-line machines used anhydrous ammonia. Anhydrous ammonia systems frequently are not installed properly (41% +), and ammonia tanks are often improperly stored (46%). The businesses inspected averaged 10 employees and 2.3 blue-line machines.