A Demonstration Of NIOSH Push-Pull Ventilation Critieria.
NIOSH 1985:23 pages
A demonstration study to evaluate NIOSH criteria for push/pull ventilation of open surface tanks was conducted. Demonstration chrome plating tanks, 4 or 6 feet wide, equipped with push/pull ventilation systems were utilized to validate earlier NIOSH findings that optimum control of emissions from laboratory tanks in a cross draft of 75 feet per minute (fpm) could be achieved with a push flow of 45 cubic feet per minute per foot of nozzle length (cfm/ft) and a pull flow of 75cfm per square foot (ft2) of tank area from 4 foot wide tanks or with a push of 35cfm/ft and a pull of 50cfm/ft2 from 6 foot tanks. Ventilation measurements and industrial hygiene sampling for total chromium (7440473) and hexavalent chromium (18540299) (Cr(VI)) were conducted. Minimum system efficiency (percent capture) ranged from approximately 60 to 70 to 92 to 95 percent for push flows of 14 to 22cfm/f2 and pull flows of 50 to 79cfm/ft2. For push flows of 14 or 22cfm/ft and pull flows of 48 to 70cfm/ft2, total chromium and Cr(VI) emmissions were below the OSHA standards, concludes that the demonstration push/pull system validates the NIOSH laboratory study.
NIOSH-Author; Quantitative-analysis; Ventilation-systems; Safety-measures; Air-sampling; Safety-equipment; Air-sampling-techniques; Analytical-instruments; Safety-research; Analytical-chemistry;
NTIS Accession No.
Division of Physical Sciences and Engineering, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, 23 pages, 2 references