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Organic Chemicals
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
An estimated 2.5 million workers are exposed to n-hexane.85–87 2-Hexanone, a derivative, is used as a paint thinner, in cleaning agents, as a solvent for dye printing, and in the lacquer industry. Acute exposure to n-hexane causes CNS depression. Chronic exposure to an average air concentration of 450–650 ppm for as little as 2 months may result in peripheral neuropathy. This neuropathy is characterized by muscular weakness, loss of sensation, and impaired gait.88,89 We do not know the consequences of lower-level exposures, but many of our chemically sensitive patients with hexane in their blood or breath do show signs of early neuropathy, which can be accentuated by inhaled challenge.
List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
2-Hexanone is a colorless to pale yellow liquid with a sharp odor. It dissolves very easily in water and is miscible in ethanol, methanol, and benzene. 2-Hexanone evaporates easily into the air as a vapor. It is stable, flammable, and incompatible with oxidizing agents, strong bases, and reducing agents. 2-Hexanone is a waste product of wood pulping, coal gasification, and oil shale operations. Formerly, 2-hexanone was in use as a paint and paint thinner with other chemical substances, and to dissolve oils and waxes.and is used as a solvent and organic synthesis intermediates. However, the industrial uses of 2-hexanone is now very much restricted.
Effects of drying temperature on the drying characteristics and volatile profiles of Citrus reticulata Blanco peels under two stages of maturity
Published in Drying Technology, 2022
Jun Wang, Hui Wang, Hong-Wei Xiao, Xiao-Ming Fang, Wei-Peng Zhang, Chang-Lu Ma
As shown in Figure 6, drying resulted in an obvious reduction in the signal intensities of 2-hexanone, 2-butanone, 2-methylpropionic acid, 1-pentanol, and 5-methyl-2-furanmethanol. These volatiles have been previously reported in citrus products,[14,47,48] and the decreased amount of these compounds can be ascribed to the high air velocity and long-time drying process employed in this study.[9] The concentration of linalool oxide in the yellow citrus peels was also reduced after drying. Linalool oxide is a glycosidically-bound terpenoid which is extensively distributed in citrus fruits and products, and has been found as a characteristic compound for grapefruit species.[14] The reduction of linalool in the yellow samples (mature) may be due to a low glycosidically-bound ability.[49] The concentration of linalool, pentanal, and neryl acetate in both the green and yellow citrus peel samples increased with the increased drying temperature from 40 to 70 °C. Generally, higher drying temperature obtained a shorter drying time, which may have contributed to the reservation of volatiles.[21] In short, air impingement drying affected the volatile profiles of citrus peels, but the impact on the characteristic flavor substances of citrus peel was not obvious.
Impact of stressors in the aviation environment on xenobiotic dosimetry in humans: physiologically based prediction of the effect of barometric pressure or altitude
Published in Journal of Toxicology and Environmental Health, Part A, 2020
Maintaining the health and well-being of men and women who execute the mission of the military is a critical aspect of our Armed Forces’ readiness strategy. The special characteristics of the military aviation operational environment and their combined impact on aircrews constitute a challenge to the health risk assessment strategies used to identify situations where risk management action is needed (Gray et al. 2019; Nicol et al. 2019). Aircraft has been noted to be a “physiologically challenged environment” due to hypobaria, acceleration, low humidity, thermal variation, vibration, and other factors (Butler et al. 2018). Standard health risks from volatile organic compounds (VOCs) are generally interpreted at ambient environmental conditions. Therefore, traditionally derived occupational exposure limits (OELs) and other guidance values may not be adequate in such settings (Sweeney et al. 2020). During aircraft operation, pilots may breathe either cabin air or, in a high-performance environment, oxygen-enriched air. In either case, the breathing air is derived from bleed air from engine compressors (Duran et al. 2019). Under routine operations, total VOCs including 2-hexanone, methylene chloride, methyl ethyl ketone, propene, ethanol, 2-propenal, acetone, isopropyl alcohol, methyl isobutyl ketone, and toluene may briefly spike after the engine is started but remain below OELs and then decline (Duran et al. 2019). However, spills and leaks may result in cabin and cockpit contamination by aviation-related compounds at elevated levels (Solbu et al. 2011).
Semi-conductor metal oxide gas sensors for online monitoring of oak wood VOC emissions during drying
Published in Drying Technology, 2019
Sebastian Paczkowski, Dirk Jaeger, Stefan Pelz
Furans, the aldehyde and the ketone were emitted at 200 °C at low rates (2.8, 0.7, 1.0 mg × L−1 × min−1, respectively) in comparison to acetic acid (25.5 mg × L−1 × min−1). At 240 °C, the furan emission rate increased (67.8 mg × L−1 × min−1), while the aldehyde and ketone emission rate was still at a low level (0.6 and 3.4 mg × L−1 × min−1, respectively). These VOC emission rates of the degradation products of lignocellulose were comparable to the emission rates of softwood.[13,16] 1-Octen-3-ol and the aliphatic short chained ketone 2-hexanone were products of oxidative lipid degradation.[20] 1-Octen-3-ol was detected as a degradation product of pine flakes in an earlier study at the same temperature, but with a lower emission rate[16] and it was also emitted by willow, birch, and poplar stored for five days at 50 °C.[21] 2-Pentylfuran was a degradation product of lipids, as well,[20] but it was not emitted from oak wood in this study. Storage and thermal degradation experiments with pine, willow, alder, birch, and poplar yielded 2-pentylfuran at high emission rates.[16,21] The emission of furfural and 5-methylfurfural was caused by the degradation of the polysaccharides hemicellulose and cellulose,[14,19] which was supported by the catalytic effect of acetic acid.[19] The temperature at the onset of the furan emission (200 °C; Figure 1) was the same in pine softwood polysaccharide degradation.[16]