Permeation of a firearm cleaning solvent through disposable nitrile gloves.

The objective was to study the interaction of the components of a complex liquid mixture on the permeation parameters of its constituents. A firearm cleaning solvent, Hoppes No. 9 Gun Bore Cleaner, was selected to challenge two varieties of disposable nitrile gloves, the thinnest (Kimberly-Clark Lavender) and thickest (Kimberly-Clark Blue), using the closed-loop ASTM F739 cell without recirculation and n-decane collection followed by quantitation of the permeated compounds using capillary gas chromatography-mass spectrometry. The thicker Blue glove resisted the permeation of Hoppe's relative to the thinner Lavender glove as shown by 3.2 times more mass permeated by the Lavender glove at 60 min despite the same standardized breakthrough times (7.5 ± 2.5 min). The kerosene fraction permeated faster at a much higher rate than expected. The Kimberly-Clark disposable nitrile glove chemical resistance guide lists a breakthrough time for kerosene of 82 min for Sterling disposable nitrile glove material. However, for Hoppe's the kerosene components appeared at the standardized breakthrough time. Mixture components that were reported by the glove manufacturer to quickly permeate the disposable nitrile material, such as ethanol, did not permeate at a rate slower than expected, indicative of a possible carrier function. A semiquantitative risk assessment confirmed the unacceptability of both gloves. Persons using personal protective equipment, such as gloves, may not be afforded the expected resistance to chemical permeation when chemicals are in a suitable mixture, hence enhancing the risk of exposure. More research is needed to produce better glove testing measures to ensure the safety of workers.

Glove permeation of chemicals: The state of the art of current practice-Part 2. Research emphases on high boiling point compounds and simulating the donned glove environment.

This second part of the review of the 21st century literature on glove permeation is divided into the following major themes; permeation data and mathematical models, exposure/risk assessment, and manufacturer data. The major issues in the literature were the demonstrations that increasing temperature and applying forces increased permeation; and that glove manufacturer data were sometimes not reproducible. Double gloving of disposable gloves was found to be effective in resisting chemical permeation for short periods of time. Harmonization of standards and commercial glove classifications were called for at conditions that were closer to the temperature and applied forces actually present in the workplace, including whole glove testing and quantitative rather than just qualitative criteria. More research was recommended in each section and subsection with particular emphasis on defining the efficiency of solid phase collection devices, and more data in areas like exposure to cosmetics, household products, liquid foods, drinks, and cleaning liquids. More research in exposure assessment for permeated chemicals with sensors on the inner glove surface and on the skin was called for. Finally, it was decided that the state of the art of current practice was in a situation that needed the permeation standards, research, and the permeation charts of glove manufacturers to be at conditions that better reflected those encountered by workers with donned gloves.

Whole glove permeation of cyclohexanol through disposable nitrile gloves on a dextrous robot hand and comparison with the modified closed-loop ASTM F739 method 1. No fist clenching.

The aim was to develop a whole glove permeation method for cyclohexanol to generate permeation parameter data for a non-moving dextrous robot hand (normalized breakthrough time tb, standardized breakthrough time ts, steady state permeation rate Ps, and diffusion coefficient D). Four types of disposable powderless, unsupported, and unlined nitrile gloves from the same producer were investigated: Safeskin Blue and Kimtech Science Blue, Purple, and Sterling. The whole glove method developed involved a peristaltic pump for water circulation through chemically resistant Viton tubing to continually wash the inner surface of the test glove via holes in the tubing, a dextrous robot hand operated by a microprocessor, a chemically protective nitrile glove to protect the robot hand, an incubator to maintain 35°C temperature, and a hot plate to maintain 35°C at the sampling point of the circulating water. Aliquots of 1.0 mL were sampled at regular time intervals for the first 60 min followed by removal of 0.5 mL aliquots every hour to 8 hr. Quantification was by the internal standard method after gas chromatography-selective ion electron impact mass spectrometry using a non-polar capillary column. The individual glove values of tb and ts differed for the ASTM closed loop method except for Safeskin Blue, but did not for the whole glove method. Most of the kinetic parameters agreed within an order of magnitude for the two techniques. The order of most protective to least protective glove was Blue and Safeskin, then Purple followed by Sterling for the whole gloves. The analogous order for the modified F739 ASTM closed loop method was: Safeskin, Blue, Purple, and Sterling, almost the same as for the whole glove. The Sterling glove was "not recommended" from the modified ASTM data, and was "poor" from the whole glove data.

Whole glove permeation of cyclohexanol through disposable nitrile gloves on a dextrous robot hand: Fist clenching vs. non-clenching.

The differences in permeation parameters when a gloved dextrous robot hand clenched and did not were investigated with the dynamic permeation system described in the companion paper. Increased permeation through the gloves of the present study for cyclohexanol when the gloved hand clenched depended on glove thickness and porosity for cyclohexanol permeation. The Sterling glove, the thinnest and most porous, was the least protective. Hand clenching promoted more permeation for the Sterling glove in terms of breakthrough times, steady state permeation rate, and diffusion coefficient. The Safeskin glove showed increased permeation only for the steady state permeation rate but not breakthrough times or diffusion coefficient. The Blue and Purple gloves showed no differences when the hand was clenching or not. The correlational analysis supported differences between the clenching and non-clenching situations, and the risk assessment considered the worst and best scenarios relative to one and two hydrated hands that were and were not protected by specific gloves.

Permeation of chlorothalonil through nitrile gloves: collection solvent effects in the closed-loop permeation method.

The aim was to measure the permeation of the fungicide chlorothalonil from Bravo Ultrex through disposable (Safeskin) and chemically protective (Solvex) nitrile glove materials in a closed-loop ASTM type permeation cell system employing different collection side solvents. The permeated fungicide was measured in the collection medium by the internal standard method through capillary gas chromatography-mass spectrometry and selective ion monitoring using m/z 222 (internal standard 4,4'-dichlorobiphenyl), and 224 and 226 (chlorothalonil). The permeated glove materials did not show swelling or shrinkage and infrared reflectance changes. Different permeated masses for the same glove material for aqueous emulsion challenges of 2.2 mg/mL Bravo Ultrex for 8 h were observed for different solvents with isopropanol>hexane>water for Safeskin, and isopropanol=hexane>water for Solvex. Solvex gloves always permeated less than Safeskin gloves for the same challenge time. When challenges with solid Bravo Ultrex occurred, chlorothalonil was still found in the collection side in the same solvent order as for the aqueous emulsion challenges, with Solvex always less than Safeskin for the same collection solvent and same challenge time. Kinetic experiments showed isopropanol was not a suitable collection solvent for Safeskin for 4 and 8 h. Hexane was not a valid collection solvent for Solvex and Safeskin for 8 h, but was better than isopropanol.

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.

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 microg/cm(2)) was higher than the threshold (0.25 microg/cm(2)) for the ASTM F739-99a closed-loop normalized breakthrough time.

Shock-synthesized hexagonal diamonds in Younger Dryas boundary sediments.

The long-standing controversy regarding the late Pleistocene megafaunal extinctions in North America has been invigorated by a hypothesis implicating a cosmic impact at the Allerød-Younger Dryas boundary or YDB (approximately 12,900 +/- 100 cal BP or 10,900 +/- 100 (14)C years). Abrupt ecosystem disruption caused by this event may have triggered the megafaunal extinctions, along with reductions in other animal populations, including humans. The hypothesis remains controversial due to absence of shocked minerals, tektites, and impact craters. Here, we report the presence of shock-synthesized hexagonal nanodiamonds (lonsdaleite) in YDB sediments dating to approximately 12,950 +/- 50 cal BP at Arlington Canyon, Santa Rosa Island, California. Lonsdaleite is known on Earth only in meteorites and impact craters, and its presence strongly supports a cosmic impact event, further strengthened by its co-occurrence with other nanometer-sized diamond polymorphs (n-diamonds and cubics). These shock-synthesized diamonds are also associated with proxies indicating major biomass burning (charcoal, carbon spherules, and soot). This biomass burning at the Younger Dryas (YD) onset is regional in extent, based on evidence from adjacent Santa Barbara Basin and coeval with broader continent-wide biomass burning. Biomass burning also coincides with abrupt sediment mass wasting and ecological disruption and the last known occurrence of pygmy mammoths (Mammuthus exilis) on the Channel Islands, correlating with broader animal extinctions throughout North America. The only previously known co-occurrence of nanodiamonds, soot, and extinction is the Cretaceous-Tertiary (K/T) impact layer. These data are consistent with abrupt ecosystem change and megafaunal extinction possibly triggered by a cosmic impact over North America at approximately 12,900 +/- 100 cal BP.

Influence of collection solvent on permeation of di-n-octyl disulfide through nitrile glove material.

The influence of collection solvents hexane and perfluorohexane on the permeation of the non-polar and non-volatile di-n-octyl disulfide (DOD) through nitrile glove material was investigated using the American Society for Testing and Materials (ASTM) F739-99a method. The weight and the thickness of the nitrile material increased about 6%, statistically significant at p

Swelling of four glove materials challenged by six metalworking fluids.

The performance of protective gloves against metalworking fluids (MWFs) has rarely been studied because of the difficult chemical analysis associated with complex MWFs. In the present study, glove swelling was used as a screening parameter of glove compatibility after challenge of the outer surfaces of chloroprene, latex, nitrile, and vinyl disposable gloves by six MWF concentrates for 2 hours in an ASTM F-739-type permeation cell without collection medium. Swelling relative to original thickness was up to 39% for latex, 7.6% for chloroprene, and 3.5% for nitrile. Shrinking up to 9.3% occurred for vinyl. Chloroprene and latex did not swell significantly for the semisynthetic and synthetic MWFs. Vinyl, previously not tested, was a good candidate for MWFs other than the soluble oil type. Although nitrile was recommended by the National Institute for the Occupational Safety and Health (NIOSH) for all types of MWFs, its swelling after 2-hour challenge was significant with Student t-tests for the soluble oil, synthetic, and semisynthetic MWFs. Glove swelling can be used as a screening chemical degradation method for mixtures such as MWFs with difficult chemical analysis. Further studies need to be conducted on the relationship between permeation and glove swelling.