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

Ahn, Kwangseog; Woskie, Susan; DiBerardinis, Louis J.; Ellenbecker, Michael J.

doi:10.1080/15459620802399989

Cited by 31 publications

(20 citation statements)

References 34 publications

(131 reference statements)

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“…Lab hood designs that provide better capture of ENM are being developed, although currently there is no standard method to evaluate the effectiveness of hoods for nanoparticles. However, even the best hood design can be compromised by sash height, distance from the source to the breathing zone, thermal loads, internal obstructions, and many other factors (66). When processes move out of the laboratory phase, there may be operations that require local exhaust ventilation.…”

Section: Control Of Nanomaterials Exposures In the Workplacementioning

confidence: 99%

Engineered Nanomaterials

Kosnett¹,

Woskie²

2012

Patty's Toxicology

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Engineered nanomaterials (ENM) represent an emerging technology with a wide range of industrial and medical applications. The toxicity of nanomaterials may vary considerably depending on numerous variables, including but not limited to composition (including impurities), size, shape, charge, aggregation status, solubility, and surface characteristics. Although this poses a challenge to the development of occupational exposure limits (OELs), some OELs have recently been proposed for selected ENMs. Based on animal data and findings associated with ambient nanoparticulates, health concerns for ENMs have focused on cardiovascular and pulmonary endpoints. The potential for exposure to ENMs can occur across the lifecycle. A precautionary approach that focuses on prevention of potential exposures and toxicity evaluation aimed at the sustainable production of these potentially valuable new products is recommended. Although there is no consensus on the value of instituting routine medical surveillance targeted to workers with potential exposure to nanomaterials, the potential utility of nanomaterial worker exposure registries has received increasing attention.

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Section: Control Of Nanomaterials Exposures In the Workplacementioning

confidence: 99%

Engineered Nanomaterials

Kosnett¹,

Woskie²

2012

Patty's Toxicology

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“…To simulate dust emission from machines there may be used test dust or tracer gases having aerodynamic parameters close to real pollution parameters. The study of pollutants emission from various processes using tracer gases carried out in Poland [5][6][7] and in the world [8][9][10][11][12][13][14][15][16][17][18][19][20][21] . Although the use of test dust better reflects real conditions of pollution emission, the tests based on tracer gases enable to make measurements with higher accuracy because these tracers do not generally exist as a real air pollution which may, however, take place in case of test dusts.…”

Section: Impact Of Air Distribution On Efficiency Of Dust Capture Fromentioning

confidence: 99%

Impact of Air Distribution on Efficiency of Dust Capture from Metal Grinding ―Bench Test Method

Jankowski

2011

Ind Health

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According to the Machinery Directive 2006/42/EC, one of the essential requirements relating to occupational safety and health hazards is to prevent dust pollution emitted by machinery during the implementation processes. Research on evaluation of emissions from machinery, according to the method of test bench using tracer gases, are currently being conducted in CIOP-PIB. This article presents some aspects of dust emission and efficiency of local exhaust ventilation (LEV) during metal grinding. Studies were performed with 10 sources of dust emissions during grinding. To evaluate the pollutants emission in the process of grinding metal products sulfur hexafluoride (SF 6 ) was selected as a tracer gas. The results show that wherever dust is emitted, the LEV should be supported by the general ventilation. Ensure good interaction between all elements of modifying the air flow and the spread of pollutants in the surroundings of the LEV is essential to effective protection of human working zone against pollutants. We used five variants of ventilation: ventilation turned off, the LEV, one-way general ventilation, mixed general ventilation and displacement general ventilation. An increase in the efficiency of dust capture depending on the source of emission by 2.5-14% was observed. This confirms that characteristics of flow resulting from the operation of ventilation is important in the spread of pollutants in the room.

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“…Recently published laboratory "fume" hoods studies have found poor correlations between laboratory hoods' face velocities and their performance measured by capture efficiency, protection efficiency, and/or smoke visualization (Volin, Joao, Reiman, Party, & Gershey, 1998;Ahn, Woskie, DiBerardinis, & Ellenbecker, 2008). This leads one to question whether capture velocities would show a similar lack of correlation to capture hood performance in terms of capture effectiveness or protection efficiency.…”

Section: Studies Of Actual Effectiveness Of Hoodsmentioning

confidence: 99%

Effectiveness of a Flanged and Unflanged Small Rectangular Capturing Hood

Kasberger¹

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Capturing hoods are an important tool for protecting workers from hazardous airborne exposures and often preferred because their small sizes offers little interference to the worker or process. Current ventilation guidelines for capturing hood assume that exceeding a recommended capture velocity ensures an acceptable degree of effectiveness. That assumption has little basis in scientific studies. This study investigated the effectiveness of a 6 inch by 12 inch rectangular capturing hood centered on a work table with a manikin acting as a surrogate for a worker. The study utilized a tracer gas (Freon-134a) to evaluate effectiveness of a capturing hood at three different hood airflows (Q), two different cross draft velocities (V cross), and with the presence or absence of a flange (Flange). The tested air flows through the hood produced velocities at the leading edge of the source (V x) of approximately 40, 100, and 140 fpm, as measured with a constant temperature anemometer. The study was conducted inside of a 9 ft high, 12 ft wide, 50 ft long wind tunnel with the manikin's back to the cross draft. Tracer gas was released from a custom made source located 11" in front of the capturing hood. The manikin was heated and "breathed." Its hands were positioned on either side of the source. Breathing zone samples from the nose (C nose) and mouth (C mouth) of the manikin were collected simultaneously to evaluate the protection efficiency of the hood. Samples were also taken simultaneously from inside the duct (C duct) to evaluate the capture efficiency of the hood. Samples were collected in 5 liter Tedlar® bags at a rate of 0.2 lpm over a period of 20 minutes for each sample. Sample bag contents were analyzed by a Gastec FT-IR. The study used a randomized factorial design with two replications. The results showed that the capturing hood was surprisingly highly effective both in terms of minimizing manikin exposures and minimizing escape of contaminant to the room environment. The concentration of Freon measured in the breathing zone was less than 1 ppm for all tests and mostly was below 0.2 ppm, even though the source concentration was over 370,000 ppm and was released at 1.79 lpm. This was true even when the capture velocity was only 50 fpm and the cross draft velocity was 60 fpm. The capture effectiveness of the hood was no less than 90% but the results may not have been reliable due to apparent measurement inaccuracies and imprecision at the Freon levels measured. The results only apply to this hood under these conditions. Testing under broader ranges of conditions would be necessary before concluding that the capturing hood is always highly effective. iii ACKNOWLEDGEMENTS This project was supported by the National Institute of Safety and Health through their training grant number: 5 T01 OH008431. I am deeply indebted to my academic advisor, chair, and mentor Dr. Steven Guffey, not only for his guidance, advice, and support through the entire thesis process, but for the guidance and advice he has imparted to me regardi...

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

Cited by 31 publications

References 34 publications

Engineered Nanomaterials

Engineered Nanomaterials

Impact of Air Distribution on Efficiency of Dust Capture from Metal Grinding ―Bench Test Method

Effectiveness of a Flanged and Unflanged Small Rectangular Capturing Hood

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