Abstract  As a groundwater contaminant, 1,4-dioxane is of considerable concern because of its toxicity, refractory nature to degradation, and rapid migration within an aquifer. Although landfill leachate has been reported to contain significant levels of 1,4-dioxane, the origin of 1,4-dioxane in leachate has not been clarified until now. In this study, the origins of 1,4-dioxane in landfill leachate were investigated at 38 landfill sites and three incineration plants in Japan. Extremely high levels of 1,4-dioxane 89 and 340 microg l(-1), were detected in leachate from two of the landfill sites sampled. Assessments of leachate and measurement of 1,4-dioxane in incineration residues revealed the most likely source of 1,4-dioxane in the leachate to be the fly ash produced by municipal solid waste incinerators. Effective removal of 1,4-dioxane in leachate from fly ash was achieved using heating dechlorination systems. Rapid leaching of 1,4-dioxane observed from fly ash in a sequential batch extraction indicated that the incorporation of a waste washing process could also be effective for the removal of 1,4-dioxane in fly ash.

Abstract  This document provides a preliminary public summary of available information collected by EPA’s Office of Pollution Prevention and Toxics (OPPT) in the Office of Chemical Safety and Pollution Prevention (OCSPP) on the manufacturing (including importing), processing, distribution in commerce, use, and disposal of this chemical. This is based on existing data available to EPA, including information collected under the Chemical Data Reporting rule, Toxics Release Inventory (if available), information from other Agency databases, other U.S. Government agencies, publicly available information from states, and a review of published literature. In addition, the document includes information reported to EPA by producers and users of the chemical in the United States and in other countries. This preliminary use information and any additional use information received in the docket by March 15, 2017 will inform efforts to develop the scope of the chemical risk evaluation required under section 6(b)(4) of the Toxic Substances Control Act, and will inform any risk management efforts following risk evaluation. Mention of trade names in this document does not constitute endorsement by EPA. To verify products or articles containing this chemical currently in commerce, EPA has identified several examples. Any lists are provided for informational purposes only. EPA and its employees do not endorse any of the products or companies. This document does not contain confidential business information (CBI).

Abstract  The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects information for the hazardous substance described here. Each peer-reviewed profile identifies and reviews the key literature that describes a hazardous substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies. The complete list of topics covered (chapter titles) is shown at the left and in more detail further down this page. The focus of the profile is on health and toxicologic information. Therefore, each profile begins with a Public Health Statement that summarizes in nontechnical language, a substance's relevant properties. A useful two page information sheet, the ToxFAQs, is also available.

Abstract  This guide is intended as a source of general industrial hygiene information for workers, employers, and occupational health professionals. It presents key information and data in abbreviated tabular form for 677 chemicals or substance groupings (e.g., manganese compounds, tellurium compounds, inorganic tin compounds, etc.) that are found in the work environment. The industrial hygiene information found in the Guide should help users recognize and control occupational chemical hazards. The chemicals or substances contained in this revision include all substances for which the National Institute for Occupational Safety and Health (NIOSH) has recommended exposure limits (RELs) and those with permissible exposure limits (PELs) as found in the Occupational Safety and Health Administration (OSHA) General Industry Air Contaminants Standard (29 CFR 1910.1000). This revision includes updated sampling and analytical methods, updated Department of Transportation (DOT) identification and guide numbers, current exposure limits, revised respirator selections, and revised IDLH (immediately dangerous to life or health concentration) values.

Abstract  An initial study of processing bioresorbable polycaprolactone (PCL) through material jetting was conducted using a Fujifilm Dimatix DMP-2830 material printer. The aim of this work was to investigate a potential solvent based method of jetting polycaprolactone. Several solvents were used to prepare a PCL solvent based ink and 1, 4-dioxane was chosen with the consideration of both solubility and safety. The morphology of PCL formed under different substrate temperatures, droplet spacings were investigated. Multi-layer PCL structures were printed and characterized. This work shows that biodegradable polycaprolactone can be processed through material jetting.

Abstract  As a part of EPA’s comprehensive approach to enhance the Agency’s management of existing chemicals, in March 2012 EPA/OPPT identified a work plan of chemicals for further assessment under the Toxic Substances Control Act (TSCA)2. After gathering input from stakeholders, EPA/OPPT developed criteria used for identifying chemicals for further assessment3. The criteria focused on chemicals that meet one or more of the following factors: (1) potentially of concern to children’s health (for example, because of reproductive or developmental effects); (2) neurotoxic effects; (3) persistent, bioaccumulative and toxic (PBT); (3) probable or known carcinogens; (4) used in children’s products; or (5) detected in biomonitoring programs. Using this methodology, EPA/OPPT identified a TSCA Work Plan of chemicals as candidates for risk assessment in the next several years. In the prioritization process, 1,4-dioxane was identified for assessment based on classification as a probable human carcinogen, wide use in consumer products, high reported releases to the environment, and presence in groundwater, ambient air and indoor environments. EPA/OPPT is performing risk assessments on chemicals in the work plan. If an assessment identifies unacceptable risks to humans or the environment, EPA will pursue risk management. The target audience for the final risk assessment is primarily EPA risk managers; however, it may also be of interest to the broader risk assessment community as well as US stakeholders interested in 1,4-dioxane. The information presented in the risk assessment may be of assistance to other federal, state and local agencies as well as to members of the general public who are interested in understanding whether there are risks from exposure to 1,4-dioxane. The initial step in the EPA/OPPT risk assessment development process, which is distinct from the initial prioritization exercise, includes planning, scoping and problem formulation. During these steps EPA/OPPT may review currently available data and information, including but not limited to, assessments conducted by others (e.g., authorities in other countries), published or readily available reports and published scientific literature. The problem formulation data review could result in refinement of pathways of interest previously identified in the initial prioritization. This document includes the results of scoping, problem formulation, and initial assessment for 1,4-dioxane. In the scoping stage, EPA/OPPT determined which chemical(s) to include and what uses to consider in the assessment. During problem formulation, EPA/OPPT identified available fate, exposure and hazard data, and characterized potential exposures, receptors and effects. EPA/OPPT developed a conceptual model and an analysis plan as a result of problem formulation.