Abstract  1,4-dioxane is a solvent used in laboratories and in adhesive products used in celluloid film processing. It's also found as a by-product in some surfactants and emulsifiers used in consumer products: detergents, cosmetics and pharmaceutical products. The National Industrial Chemical Notification and Assessments Scheme (NICNAS) assessed 1,4-dioxane in May 1994. Following are the main findings of the assessment. A workplace product containing more than 0.1% 1,4-dioxane is classed as a hazardous substance. 1,4-dioxane is in Class 3, (Packing Group II) under the Australian Dangerous Goods Code. 1,4-dioxane is highly flammable and may react with light and air to form explosive substances. It is a scheduled poison with limits set for the levels in consumer products. 1,4-dioxane poisoning can occur through the skin, swallowing or by inhalation. Of these, breathing 1,4-dioxane vapour is the most likely way for poisoning to occur. High exposure can result in liver and kidney damage and death. 1,4-dioxane is an eye and respiratory irritant. 1,4-dioxane causes cancer in animals after prolonged exposure.

Abstract  Personal and area air samples were collected in two film laboratories (SIC-7819) in Hollywood, California for formaldehyde (50000), acetic-acid (64197), and organic solvents. Evaluation was requested by the Film Technicians Local No. 683 and was performed in 1980 and 1981. A medical questionnaire was distributed. Formaldehyde concentrations were below California standards of 2 parts per million in one laboratory. Acetic-acid was under the limit of detection of 0.05 milligrams. In the second laboratory, organic vapor and acetic-acid were below evaluation criteria except for methyl-chloroform (71556) which showed one area sample concentration of 4431 milligrams per cubic meter (mg/m3) (NIOSH standard is 1900mg/m3) but this was not an area where employees were normally exposed. Formaldehyde concentrations in this laboratory occasionally exceeded evaluation standards 5 fold. Symptoms reported were: persistent irritant contact dermatitis; eye and upper respiratory irritation; transient defatting dermatitis; and anesthetic effects on fingers. The group exposed to final products reported irritation to eyes and upper respiratory system. The bleach accelerator process produced severe dermatitis in a high proportion of workers; organic solvents and residual formaldehyde in final products produced milder symptoms. The authors conclude that employees are overexposed only to formaldehyde at one laboratory.

Abstract  Increasing regulatory attention to 1,4-dioxane has prompted the United States Air Force (USAF) to evaluate potential environmental liabilities, primarily associated with legacy contamination, at an enterprise scale. Although accurately quantifying environmental liability is operationally difficult given limited historic environmental monitoring data, 1,4-dioxane is a known constituent (i.e., stabilizer) of chlorinated solvents, in particular 1,1,1-trichloroethane (TCA). Evidence regarding the co-occurrence of 1,4-dioxane and trichloroethylene (TCE), however, has been heavily debated. In fact, the prevailing opinion is that 1,4-dioxane was not a constituent of past TCE formulations and, therefore, these two contaminants would not likely co-occur in the same groundwater plume. Because historic handling, storage, and disposal practices of chlorinated solvents have resulted in widespread groundwater contamination at USAF installations, significant potential exists for unidentified1,4-dioxane contamination. Therefore, the objective of this investigation is to determine the extent to which 1,4-dioxane co-occurs with TCE compared to TCA, and if these chemicals are co-contaminants, whether or not there is significant correlation using available monitoring data. To accomplish these objectives, the USAF Environmental Restoration Program Information Management System (ERPIMS) was queried for all relevant records for groundwater monitoring wells (GMWs) with 1,4-dioxane, TCA, and TCE, on which both categorical and quantitative analyses were performed. Overall, ERPIMS contained 5,788 GMWs from 49 installations with records for 1,4-dioxane, TCE, and TCA analytes. 1,4-Dioxane was observed in 17.4% of the GMWs with detections for TCE and/or TCA, which accounted for 93.7% of all 1,4-dioxane detections, verifying that 1,4-dioxane is seldom found independent of chlorinated solvent contamination. Surprisingly, 64.4% of all 1,4-dioxane detections were associated with TCE independently. Given the extensive dataset, these results conclusively demonstrate for the first time that 1,4-dioxane is a relatively common groundwater co-contaminant with TCE. Trend analysis demonstrated a positive log-linear relationship where median 1,4-dioxane levels increased between ∼6% and ∼20% of the increase in TCE levels. In conclusion, this data mining exercise suggests that 1,4-dioxane has a probability of co-occurrence of ∼17% with either TCE and/or TCA. Given the challenges imposed by remediation of 1,4-dioxane and the pending promulgation of a federal regulatory standard, environmental project managers should utilize the information presented in this paper for prioritization of future characterization efforts to respond to the emerging issue. Importantly, site investigations should consider 1,4-dioxane a potential co-contaminant of TCE in groundwater plumes. Integr Environ Assess Manag © 2012 SETAC.

Abstract  Fundamental understanding of thermodynamic of phase separation plays a key role in tuning the desired features of biomedical devices. In particular, phase separation of ternary solution is of remarkable interest in processes to obtain biodegradable and biocompatible architectures applied as artificial devices to repair, replace, or support damaged tissues or organs. In these perspectives, thermally induced phase separation (TIPS) is the most widely used technique to obtained porous morphologies and, in addition, among different ternary systems, polylactic acid (PLLA)/dioxane/water has given promising results and has been largely studied. However, to increase the control of TIPS-based processes and architectures, an investigation of the basic energetic phenomena occurring during phase separation is still required. Here we propose an experimental investigation of the selected ternary system by using isothermal titration calorimetric approach at different solvent/antisolvent ratio and a thermodynamic explanation related to the polymer-solvents interactions in terms of energetic contribution to the phase separation process. Furthermore, relevant information about the phase diagrams and interaction parameters of the studied systems are furnished in terms of liquid-liquid miscibility gap. Indeed, polymer-solvents interactions are responsible for the mechanism of the phase separation process and, therefore, of the final features of the morphologies; the knowledge of such data is fundamental to control processes for the production of membranes, scaffolds and several nanostructures. The behavior of the polymer at different solvent/nonsolvent ratios is discussed in terms of solvation mechanism and a preliminary contribution to the understanding of the role of the hydrogen bonding in the interface phenomena is also reported. It is the first time that thermodynamic data of a ternary system are collected by mean of nano-isothermal titration calorimetry (nano-ITC). Supporting Information is available.