Permeation of Ethoxy- and Butoxy- Ethanols Through a Disposable Nitrile Glove

The purpose of this study was to investigate the permeation of the glycol ethers, 2-ethoxyethanol (2-EE) and 2-butoxyethanol (2-BE) through disposable, nitrile exam gloves using a modified ASTM closed-loop module. The purple unsupported, unlined, powderless nitrile glove from Kimberly-Clark was challenged by the two pure glycol ethers. Their permeation parameters were measured with the aid of a 2.54 cm ASTM F739 closed-loop permeation cell using water collection at 35.0±0.5 0C in a moving tray water bath, and capillary gas chromatography-mass spectrometry for quantification. Each set of experiments consisted of four standard permeation cells with water as the collection solvent. The steady state permeation rate for 2-EE of 4.83±0.45 µg/cm2/min was about 4 times that of 2-BE (1.27±0.11 µg/cm2/min). Permeation of the more nonpolar 2-BE was less than for 2-EE. Both solvents exceeded the ASTM threshold normalized breakthrough time in the closed-loop testing module. Glove samples failed to pass permeation criteria defined by Kimberly Clark and Ansell. Such gloves are not recommended as personal protective equipment for exposure to 2-butoxyethanol or 2-ethoxyethanol, even for very short period exposures. Glove manufacturers should reconsider existing permeation testing method for low volatile compounds and apply the closed-loop module due to higher sensitivity and accuracy

Permeation of a Metalworking Fluid Through a Latex Glove Under Field Use Conditions

Whole glove testing for a metalworking fluid (MWF) in the field was performed for the first time. Green latex gloves used in a machine shop were exposed for 20 min to MWF. The permeated amount (1.0 ± 0.5 μg/cm2) was higher than the threshold (0.25 μg/cm2) for the ASTM F739-99a closed-loop normalized breakthrough time

Permeation of Herbicidal Dichlobenil From a Casoron Formulation Through Nitrile Gloves

The aim of this study was to measure permeation of the herbicide dichlobenil in Casoron 4G through disposable and chemically protective nitrile gloves using an American Society for Testing and Materials-type permeation cell and a closed-loop system employing two different solvents (hexane and water) and two different challenge situations (aqueous emulsion and solid formulation). Capillary gas chromatography–mass spectrometry was used for quantification purposes. The chemically protective glove did not allow any permeation up to 8 h for the solid-formulation and water-collection challenges, but permeation was detected in all other challenges. The disposable glove allowed the most permeation, and the solid-formulation challenge with water collection necessitated that a dichlobenil equivalent be calculated because of the presence of its hydrolysis degradation product 2,6-dichlorobenzamide. Permeation from the solid formulation was detectable by hexane collection for both the disposable and chemically protective gloves and by water collection for the disposable glove. It was concluded that hexane-solvent collection was not valid for the disposable glove at 4 and 8 h of permeation in the solid Casoron challenge or for the aqueous emulsion challenge at 8 h relative to the water-collection solvent data. The hexane-solvent collection for the chemically protective glove was valid for the 8-h solid-formulation challenge but not for the 8-h aqueous-solution challenge. All water-solvent collections were valid; however, dichlobenil usually permeated the gloves

Discovery of a nanodiamond-rich layer in the Greenland ice sheet

We report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5!106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 0.1 ka. However, more investigation is needed to confirm this association

Permeation of a Metalworking Fluid Through a Latex Glove Under Field Use Conditions

Whole glove testing for a metalworking fluid (MWF) in the field was performed for the first time. Green latex gloves used in a machine shop were exposed for 20 min to MWF. The permeated amount (1.0 ± 0.5 μg/cm2) was higher than the threshold (0.25 μg/cm2) for the ASTM F739-99a closed-loop normalized breakthrough time

Permeation of a Metalworking Fluid Through a Latex Glove Under Field Use Conditions

Whole glove testing for a metalworking fluid (MWF) in the field was performed for the first time. Green latex gloves used in a machine shop were exposed for 20 min to MWF. The permeated amount (1.0 ± 0.5 μg/cm2) was higher than the threshold (0.25 μg/cm2) for the ASTM F739-99a closed-loop normalized breakthrough time