ASSE Z9.9

Abstract

This Standard discusses portable ventilation equipment and systems used for the reduction, control, or prevention of exposure to hazardous atmospheres or airborne substances in the occupational environment, and for provision of comfort to employees. <br>Portable ventilation systems are an important engineering control for establishing and maintaining acceptable air quality and supplementing the effectiveness of fixed systems in the work environment. The major approaches employed in the use and application of portable ventilation systems include provision of tempered air to provide and maintain comfort, displacement of airborne contaminants from the workspace, dilution of airborne contaminants in the workspace, supplying breathable air to eliminate or prevent oxygen deficiency in an environment, and the capture or containment of airborne contaminants at or as close as possible to the point of generation. Properly designed, installed, and operated portable ventilation systems can provide excellent control of airborne contaminants. <br>Some sections of this Standard are written to stand alone. As a result, they may duplicate requirements of other sections. <br>This Standard establishes minimum requirements for the design, construction, and labeling of portable ventilation equipment and systems. <br>This Standard also establishes fundamental requirements for the application, management, operation, maintenance, performance validation, and testing of portable ventilation equipment and systems to ensure satisfactory performance over their lifetime. <br>This Standard covers components of portable ventilation systems, including: <br>&#8212; air movers and their modes of power <br>&#8212; other components of portable ventilation systems including entry hoods; duct, hose, and other conveying structures; air-cleaning equipment including filters and sorbent air-purifying devices; and air coolers and heaters. <br>This Standard does not intend to address every application and technical problem that arises during the use of portable ventilation systems in industry. The manner in which portable ventilating equipment is used requires judgement and discretion by the end-user. <br>There is no simple formula governing decisions concerning use of this equipment. The end user should refer to appropriate technical references and publications, such as included here, for further guidance on uses and applications and strengths and limitations of portable ventilation systems in specific applications. <br>The Standard does not cover: <br>&#8212; air recirculation systems, such as recirculating fume hoods, intended for use in laboratory applications <br>&#8212; air moving systems that are part of an industrial process <br>Where provisions of this Standard conflict with other Standards, the more stringent shall apply.