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A pilot study on the effects of two ventilation methods on weld fume exposures in a shipyard confined space welding task.
Wurzelbacher-SJ; Hudock-SD; Johnston-OE; Blade-LM; Shulman-SA
Appl Occup Environ Hyg 2002 Nov; 17(11):735-740
Current methods to ventilate confined spaces can differ dramatically in contaminant removal efficiency and usually fall into one of two categories: dilution ventilation (DV) or local exhaust ventilation (LEV). Dilution ventilation involves inducing quantities of fresh air to flow into a confined space, often at high velocity. Under certain conditions, this flow creates a mixing or turbulence that can force contaminated air out of any available openings in the space. The main advantage of this method is that it can be applied to a confined space that has only a single opening because the method does not rely on a directional flow to draw contaminants away from the worker. However, DV with resulting turbulence can be very inefficient in removing contaminants from a welder's personal breathing zone (PBZ). Since air flow is not unidirectional, contaminants may be reintroduced into the PBZ before being forced out of the space. This effect can be compounded by worker position and posture if the initial direction of air flow is generally toward the welder's back, creating eddies and mixing of the air in front of the worker.
Ventilation; Welding; Fumes; Exposure-levels; Air-flow; Work-environment; Workers
Division of Applied Research and Technology, 4676 Columbia Parkway, Cincinnati, OH 45226
Issue of Publication
Work Environment And Workforce; Mixed Exposures
Applied Occupational and Environmental Hygiene
Page last reviewed: March 11, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division