Additionally, this research identified the possible factors which could contribute to breathing zone concentration variations. The breathing zone is defined as being within a 30 cm radius of nose and mouth. Where exposure monitoring is required, determinations of exposure will be made from breathing zone air samples that are representative of the 8-hour TWA and. This research revealed that the chest sampler provides a consistent relationship to the concentrations measured at the nose for a given job category. In this method the air sample is collected within the breathing zone of worker. Styrene air concentrations detected at the nose were significantly different than those concentrations detected at the other three locations and represented 90 percent, 84 percent, and 76 percent of the left lapel, right lapel, and chest samplers, respectively. Two job classes were studied: the spray gun operators and the rolling and tucking operators. An extensive field investigation in a boat manufacturing plant was conducted where styrene air concentrations were measured by mounting four 3M one-stage diffusion samplers around the worker's breathing zone. It has been generally assumed that vapor is uniformly mixed in the breathing zone therefore, samplers are placed on either lapel or on the chest of the worker. Breathing zone air samples being taken during replacement of brake shoe linings.
This zone is considered to have an airborne chemical concentration equivalent to the concentration breathed by the worker. It is the area from which the employee draws air and has been defined as being as close as possible to the nose and mouth and a hemisphere forward of the shoulders with a radius of 6 to 9 inches. Bulk sampling A bulk sample of a raw material or contaminant is taken to determine its chemical make-up. A Breathing Zone in Industrial Hygiene terminology refers to the area that one takes a personal air sample in for industrial hygiene air sampling. Area sampling Sample is obtained in an area representative of a process, a 'worst case', or multiple worker's exposure. samplers are effectively outside the breathing zone of the worker. Breathing zone sampling Sample is obtained in the breathing zone of a specific worker. Full-shift sampling should be done when miners will be welding or exposed to other fume sources for all or most of their work shift. The cassette must be placed under the hood whenever possible. in a workplace by sampling a workers breathing zone for the whole workday (a filter. The breathing zone of a welder wearing a welding hood is considered to be under the hood. Breathing zone samples are used to estimate worker exposure to airborne contaminants by collecting air from a vaguely defined zone surrounding the head. For occupational hygiene purposes it is important to consider the concentration and. Many industrial hygienists feel that OSHA compliance limits are not.
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