The effect of operating conditions on fume cupboard containment

Johnson, A.E.; Fletcher, B.

doi:10.1016/s0925-7535(96)00068-9

Cited by 25 publications

(19 citation statements)

References 1 publication

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“…(19,20,22,23,26) One study (52) reported that the significant difference between the supply air and room air temperature increased leakage from the hood; there were no other studies reported on this topic. Cross draft (caused by external airflows, by pumping doors, or by walking past a hood) reduced hood performance in most of the reported cases, (17,18,22,26,40,44,47,51) but two studies (34,47) reported only small effects from cross flows generated by blowing air from a diffuser grille across the hood face, or cross draft caused by walking by the hood. One study (47) reported that, compared with the base condition in which the fume hood was located without an adjacent wall, operating a hood in a corner location did not significantly affect hood performance.…”

Section: Room Air and Environmental Factorsmentioning

confidence: 95%

“…(16,27,33,(39)(40)(41) One study (40) reported that a warm mannequin and a human operator caused higher leakage concentrations than an unheated mannequin. Four studies consistently reported that when different tracers, contaminant release rates, or ejectors were used while other conditions were not changed, breathing zone concentrations varied.…”

Section: Test Methodsmentioning

confidence: 99%

“…Some studies (16,19,20,24,28,39,44,(50)(51)(52) found improved hood performance with increased face velocity. However, other studies (6,7,(17)(18)(19)(20)(21)(22)(23)(27)(28)(29)31,32,34,40,42,45,53,54) reported no significant relationship between hood performance and face velocity; two studies (28,34) even reported higher breathing concentrations with increasing face velocity. One study (51) reported higher exposure for the hoods with higher spatial and temporal variations of the face velocities, but it was the only study of these factors.…”

Section: Studies Findingsmentioning

confidence: 96%

“…Exhaust volume rate Generally, higher breathing zone concentrations with higher flow rates, but not conclusive due to the influence of other confounding factors (49) 1 N o Lower hood leakages with increased exhaust airflow rates (15) increasing the face velocity does not necessarily improve containment (6,7,(17)(18)(19)(20)(21)(22)(23)(27)(28)(29)31,32,34,40,42,45,53,54) 18…”

Section: Hood Design Elements and Operating Variablesmentioning

confidence: 99%

See 3 more Smart Citations

A Review of Published Quantitative Experimental Studies on Factors Affecting Laboratory Fume Hood Performance

Ahn¹,

Woskie²,

DiBerardinis

et al. 2008

Journal of Occupational and Environmental Hygiene

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This study attempted to identify the important factors that affect the performance of a laboratory fume hood and the relationship between the factors and hood performance under various conditions by analyzing and generalizing the results from other studies that quantitatively investigated fume hood performance. A literature search identified 43 studies that were published from 1966 to 2006. For each of those studies, information on the type of test methods used, the factors investigated, and the findings were recorded and summarized. Among the 43 quantitative experimental studies, 21 comparable studies were selected, and then a meta-analysis of the comparable studies was conducted. The exposure concentration variable from the resulting 617 independent test conditions was dichotomized into acceptable or unacceptable using the control level of 0.1 ppm tracer gas. Regression analysis using Cox proportional hazards models provided hood failure ratios for potential exposure determinants. The variables that were found to be statistically significant were the presence of a mannequin/human subject, the distance between a source and breathing zone, and the height of sash opening. In summary, performance of laboratory fume hoods was affected mainly by the presence of a mannequin/human subject, distance between a source and breathing zone, and height of sash opening. Presence of a mannequin/human subject in front of the hood adversely affects hood performance. Worker exposures to air contaminants can be greatly reduced by increasing the distance between the contaminant source and breathing zone and by reducing the height of sash opening. Many other factors can also affect hood performance. Checking face velocity by itself is unlikely to be sufficient in evaluating hood performance properly. An evaluation of the performance of a laboratory fume hood should be performed with a human subject or a mannequin in front of the hood and should address the effects of the activities performed by a hood user.

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Section: Room Air and Environmental Factorsmentioning

confidence: 95%

Section: Test Methodsmentioning

confidence: 99%

Section: Studies Findingsmentioning

confidence: 96%

Section: Hood Design Elements and Operating Variablesmentioning

confidence: 99%

See 2 more Smart Citations

A Review of Published Quantitative Experimental Studies on Factors Affecting Laboratory Fume Hood Performance

Ahn¹,

Woskie²,

DiBerardinis

et al. 2008

Journal of Occupational and Environmental Hygiene

View full text Add to dashboard Cite

show abstract

“…Research has shown that the passage of a person past the hood face at walking speeds creates a turbulent wake sufficient to pull contaminants from the hood [Johnson and Fletcher 1996].…”

mentioning

confidence: 99%

General safe practices for working with engineered nanomaterials in research laboratories.

2012

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To receive documents or other information about occupational safety and health topics, contact NIOSH at Telephone: 1-800-CDC-INFO (1-800-232-4636) TTY: 1-888-232-6348 E-mail: cdcinfo@cdc.gov or visit the NIOSH Web site at www.cdc.gov/niosh.For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting www.cdc.gov/niosh/eNews. DHHS (NIOSH) Publication No. 2012-147 May 2012 Safer • Healthier • People TM General Safe Practices for Working with Engineered Nanomaterials in Research Laboratoriesiii ForewordThe National Institute for Occupational Safety and Health (NIOSH) is pleased to present General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories. Engineered nanomaterial applications are rapidly expanding throughout the United States and worldwide. The research community is at the front line of creating these new nanomaterials, testing their usefulness in a variety of applications, and determining their toxicological and environmental impacts.With the publication of this document, NIOSH hopes to raise awareness of the occupational safety and health practices that should be followed during the synthesis, characterization, and experimentation with engineered nanomaterials in a laboratory setting. The document contains recommendations on engineering controls and safe practices for handling engineered nanomaterials in laboratories and some pilot scale operations. This guidance was designed to be used in tandem with well-established practices and the laboratory's chemical hygiene plan. As our knowledge of nanotechnology increases, so too will our efforts to provide additional guidance materials for working safely with engineered nanomaterials. AcknowledgmentsThis document is based on input from several subject matter experts and was initiated as a joint effort under a Memorandum of Understanding between NIOSH and the Center for High-rate Nanomanufacturing (CHN). Some of the specific content was derived from a report generated by Michael Ellenbecker and Su-Jung (Candace) Tsai at the University of Massachusetts Lowell (UMass Lowell), one of the CHN member campuses, and was supported by a contract from the NIOSH Nanotechnology Research Center (NTRC). Paul Schulte is the manager and Charles Geraci is the coordinator of the NIOSH nanotechnology cross-sector program. Special thanks go to Catherine Beaucham and Laura Hodson for writing and organizing this report. Others who contributed substantially to the writing and research include Mark Hoover and Ralph Zumwalde. Executive SummaryNanotechnology, the manipulation of matter at a nanometer scale to produce new materials, structures, and devices having new properties, may revolutionize life in the future. It has the potential to impact medicine through improved disease diagnosis and treatment technologies and to impact manufacturing by creating smaller, lighter, stronger, and more efficient products. Nanotechnology could potentially decrease the impact of pollution by improving methods for water purification or energy conservation....

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Impact of heat generation and use of experimental instruments in a fume hood on pollutant capture efficiency

Muta

Ito

2022

Japan Architectural Review

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A fume hood is a local ventilation system that is typically installed in a laboratory space to ensure the safety of workers from chemical exposure. A fume hood is designed to capture hazardous gas‐phase pollutants generated inside a box‐like enclosure, and the pollutant capture efficiency is regulated by the average opening surface air velocity. However, few cases exist in which the pollutant capture efficiency inside the fume hood is precisely analyzed and quantitatively visualized. In this study, the capture performance of a fume hood under actual use conditions was evaluated using computational fluid dynamics (CFD). The factors that could affect the performance, that is, the exhaust airflow rate, experimental instruments inside, worker in front, and heat source within the fume hood, were parametrically considered. The numerical analyses revealed that experimental instruments near the opening surface significantly affected the airflow into the fume hood and decreased its capture performance. Under the inadequate condition of a low exhaust airflow rate, pollutant leakage inside the chamber was observed due to the presence of a worker in front of the fume hood and the heat source inside. Furthermore, the pollutant capture performance was slightly improved by changing the layout/position of the experimental instrument.

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The effect of operating conditions on fume cupboard containment

Cited by 25 publications

References 1 publication

A Review of Published Quantitative Experimental Studies on Factors Affecting Laboratory Fume Hood Performance

A Review of Published Quantitative Experimental Studies on Factors Affecting Laboratory Fume Hood Performance

General safe practices for working with engineered nanomaterials in research laboratories.

Impact of heat generation and use of experimental instruments in a fume hood on pollutant capture efficiency

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