In-depth survey report: control of dust in a textile dyeing transfer operation at Logisco Corporation, Charlotte, North Carolina, Report No. CT-226-12a.
The National Institute for Occupational Safety and Health conducted an evaluation of control techniques for reducing occupational exposure to dye dust in a textile dye transfer operation. The purpose of this evaluation was to detennine the efficiency of various techniques for controlling exposure of weigh-out and transfer operators where dry powder dyes were removed from large drums and weighed into smaller containers. Because the toxicity of these powder dyes is not well defined, it is prudent to control employees' exposure as far as practical. The goal of this study was to detennine the efficiency of two available techniques to control this exposure. Dry powdered dyes of many chemical types are used extensively in the coloring of textiles. These dyes are typically provided in bulk containers holding up to several hundred pounds and are removed as needed in measured amounts to be used alone or combined with measured quantities of other dyes to produce a desired color. This process where the powders are scooped from open containers and dumped into smaller containers is the time of greatest potential exposure to employees. To reduce workers' exposure during transfer operations, NIOSH, in collaboration with the Ecological and Toxicological Association of Dyes and Organic Pigments Manufacturers (ET AD), investigated two control solutions: 1) the addition of a "de-dusting agent," typically a light oil, to the dye to reduce the dye's tendency to become and stay airborne; and 2) the size of the containers used to ship and store the dyes. Previously, a commercially available down draft hood designed specifically for use in the weigh-out and transfer operation and installed in a dye house in Brooklyn, New York, had been evaluated in a prior NIOSH study that indicated it was effective in the reduction of dye dust in the work environment. Evaluations of the effectiveness of the de-dusting agent and the container size were also conducted during that prior study but were inconclusive principally due to the effects ofthe hood. The addition of a de-dusting agent to reduce dye dustiness is a common procedure for materials manufactured and shipped in the US, and is thought by some in the industry to significantly reduce airborne (i.e., inhalable) dye dust concentrations. Varying. amounts of oil are mixed with the dye by the manufacturer, with a concentration of about 1 % w/w as a nominal maximum. Many ofthe dyes of interest are shipped and used from standard 55 gallon plastic drums, and previous studies had shown that the occupational exposure of employees during the transfer would increase as that employee was required to reach lower into the barrel as the dye was used!. Therefore, the concept of using short or "half' barrels, similar in diameter but smaller in height than a standard barrel, was developed with the hope of eliminating the need for the weigh-out operator to reach so far into the barrel that his head (i.e., breathing zone) was placed into this area of high dust concentration. A study was designed to test these two variables (dustiness and drum size) and their interactions in either the presumed "controlled" or "uncontrolled" mode. Tests were conducted in a work area containing no local exhaust ventilation (i.e., down draft hood), using dye to which a maximum amount of de-dusting oil had been added and to which no oil was added; and scooping the samples from both the short and the standard sized drums.
Dusts; Dust-particles; Dyeing-industry; Dyes; Workers; Occupational-exposure; Dust-samplers; Dust-sampling; Particulate-dust; Particulates; Respiratory-system-disorders; Pulmonary-system-disorders; Dermatitis; Region-4; Coloring-materials; Control-technology; Storage-containers; Ventilation-equipment; Ventilation-hoods