Using screening test data to recognize reactive chemical hazards

The evaluation of reactive hazards is necessary for safe operations in the chemical process industries. An integral aspect of reactive hazard testing is the screening of chemicals to focus experimental efforts on the more hazardous chemicals. Screening is often performed using a Differential Scanning Calorimeter (DSC) or the Reactive System Screening Tool (RSST). The study of chemical incompatibility highlights the need for efficient screening techniques, since a large number of experiments must be performed at a reasonable cost and in a short period of time. A purpose of this paper is to present chemical incompatibility data measured using the RSST for di-tert-butyl peroxide (DTBP) in a variety of organic solvents. Analysis of the data with regard to the solvent functional groups was generalized to extend the measured data to compounds for which data are unavailable. Further, a classification for reactive chemicals is proposed that can serve as a guideline for selecting compositions for detailed testing.     

Rapid, State-of-the-Art Techniques for the Detection of Toxic Chemical Adulterants in Water Systems

Recent events have heightened awareness concerning potential hazardous threats to U.S. populace. The causes of concern include a possible contamination of water systems through harmful chemical agents resulting in sickness or death among consumers. To forestall the consequences of high-risk chemical contaminants that can potentially pollute our water resources, swift intervening measures need to be taken as a first line of defense. This aspect of environmental protection involves the design, testing, and installation of detection devices that protect U.S. water supply systems from toxic chemicals. These sensing devices are based on physical, chemical, biological, and radiological methods of detection. Traditional analytical tools are rather cumbersome, time-consuming, and expensive to operate. On the other hand, contemporary trends in the fight against toxic chemical threats to domestic and industrial water facilities comprise of sensors designed to achieve rapid, highly sensitive, and cost-effective detection, and intervention. This paper samples the state-of-the-art in detection techniques for toxic chemical antagonists with emphasis on heavy metals and cyanide compounds that can be potentially deleterious to U.S. water systems. The goal is to identify rapid, realistic and reliable methods, as early warning systems, to mitigate the effects of toxicants in water systems.     

Emerging technologies for the control of hazardous wastes

Investigations were conducted of new and emerging technologies for the disposal of hazardous wastes. These methods involve new technologies or a recent variation on an established one. In addition, a survey was made of potential users of hazardous waste information. The need for a data base for emerging hazardous waste techonologies and/or a newsletter was evaluated. Information on the emerging technologies was acquired by computerized search, library searching, and personal contacts. The emerging technologies discussed include molten salt combution, fluidized bed incineration, high energy electron treatment of trace organic compounds in aqueous solution, the catalyzed wet oxidation of toxic chemicals, dehalogenation of compounds by treatment with ultraviolet (UV) light and hydrogen, UV/ chlorinolysis of organics in aqueous solution, the catalytic hydrogenation-dechlorination of polychlorinated biphenyls (PCBs), and ultraviolet/ozone destruction. Theory, specific wastes treated, and economics are discussed.The major technologies investigated in details were molten salt combustion, fluidized bed incineration, and ultra-violet/ozone destruction.Among the waste treated by emerging technologies are PCBs, various Dioxins, pesticides and herbicides, chemical warfare agents, explosives and propellants, nitrobenzene, and hydrazine plus its derivatives.This document encompasses a target audience ranging from laymen to natural scientists. The information presented here was derived solely for application to hazardous wastes. Readers requiring more specific information about theory and the economics of start-up plus operating and maintenance costs for technologies that may by applied to a specific hazardous waste not discussed in this report are referred to the literature cited in this report and to documents about state-of-the-art situations for a particular technology.     

U.S. coast guard research and development program for hazardous chemical discharge response

The U.S. Coast Guard's Office of Research and Development is presently conducting a program to develop equipment and methods for responding to discharges of hazardous chemicals into the waters of the United States. The program to ameliorate hazardous chemical discharges has been divided into six project areas. This paper will provide an overview of these six project areas as follows:1. Prevention and Reduction: The development of techniques to prevent or reduce the discharge of a hazardous chemical.2. Personnel Protection: The development of protective clothing, life support systems and personnel monitors for personnel responding to chemical discharges.3. Detection, Identification, and Quantification: The development of techniques to allow response personnel to detect, identify and determine the concentration of hazardous chemical discharges.4. Hazard Assessment Modeling: The development and refinement of mathematical models to predict the behavior of discharged hazardous chemicals.5. Containment, Treatment, and Recovery: The development of hardware and methods to respond to a discharge and mitigate its environmental damage.6. Disposal: The development of methods to dispose of chemicals which have been recovered.When completed, each of these project areas should provide the Coast Guard with additional capability to respond to hazardous chemical discharges.     

Incompatibilities of chemicals

Chemical incompatibilities are potentially significant problems where hazardous chemicals are found. A number of chemical segregation systems have been developed which provide recommendations for the separation of incompatible chemicals. Three segregation systems were identified in this study: the UN Dangerous Goods system (which uses physical hazard as the main reason for segregation and has 14 categories), the US CHRIS system (which uses chemical reactivity and has 24 categories) and a third system which uses environmental risks (and has 25 categories). These systems were combined. Merging of each system was initially problematic, but became considerably easier once certain characteristics had been defined (such as flammability or water incompatibility). This gave a final merged incompatibility table containing 100 different segregation groups. This research study showed that it was possible to combine different segregation systems based on different criteria and that more comprehensive segregation systems can be developed. These can be of use in the decision-making process about where groups of chemicals may be used, and during the use of chemicals, where chemicals should not be combined. The use of more comprehensive segregation systems will also assist in developing proper measures for their control.     

A proposed occupational health and safety risk estimation tool for manufacturing systems

There are numerous hazards to be found in almost any workplace. Annually, millions of workers die, are injured or become ill as a result of these occupational hazards. Industrial machines are often involved in these occupational accidents. Because of the demands of regulatory compliance, and the potentially high cost in terms of human suffering and lost production, businesses should place particular emphasis on safety measures. Risk is defined as a combination of the probability of harm and the severity of its consequences. Generally, risk estimation involves examining the hazards associated with a situation or with the use of a machine. A large number of techniques have been proposed for risk estimation, and recent studies have revealed that some of them have serious flaws. The main objective of this paper is to develop a proposed risk assessment tool based on the findings of an earlier study. Our research results constitute a first step towards the integration of occupational health and safety (OHS) concerns into facility planning models which traditionally do not consider OHS. The proposed risk estimation tool is developed based on the characteristics, strengths and weaknesses of 31 existing risk estimation tools, and is then applied to 20 scenarios representing different hazardous situations. To evaluate the performance of the proposed tool, the results were compared with those of other risk estimation tools and confirmed its proposed ability to estimate risk relative to other risk estimation tools.     

The development of the globally harmonized system (GHS) of classification and labelling of hazardous chemicals

The hazards of chemicals can be classified using classification criteria that are based on physical, chemical and ecotoxicological endpoints. These criteria may be developed be iteratively, based on scientific or regulatory processes. A number of national and international schemes have been developed over the past 50 years, and some, such as the UN Dangerous Goods system or the EC system for hazardous substances, are in widespread use. However, the unnecessarily complicated multiplicity of existing hazard classifications created much unnecessary confusion at the user level, and a recommendation was made at the 1992 Rio Earth summit to develop a globally harmonized chemical hazard classification and compatible labelling system, including material safety data sheets and easily understandable symbols, that could be used for manufacture, transport, use and disposal of chemical substances. This became the globally harmonized system for the Classification and Labelling of Chemicals (GHS). The developmental phase of the GHS is largely complete. Consistent criteria for categorising chemicals according to their toxic, physical, chemical and ecological hazards are now available. Consistent hazard communication tools such as labelling and material safety data sheets are also close to finalisation. The next phase is implementation of the GHS. The Intergovernmental Forum for Chemical Safety recommends that all countries implement the GHS as soon as possible with a view to have the system fully operational by 2008. When the GHS is in place, the world will finally have one system for classification of chemical hazards.     

用于食品包装材料成分迁移数学模型的研究进展

目的综述目前食品用包装材料中成分迁移的数学模型及相关研究进展,为迁移数学模型的推广和进一步开发提供有价值的参考。方法分析影响食品包装材料中化学成分向食品迁移的因素,介绍几种应用较广的迁移模拟软件,论述不同类型迁移数学模型的适用性及优缺点,并说明其在食品包装材料法规标准及化学成分暴露风险评估中的应用。结果许多学者的研究都证明迁移数学模型可部分代替迁移实验,产生的结果可靠且具有代表性。结论迁移模型是一种预测化学物质从食品包装材料迁移到食品中的有效工具,虽可在一定程度上代替迁移实验从而节省成本,但迁移模型的应用还存在许多问题亟需解决。     

Combining U.S.-based prioritization tools to improve screening level accountability for environmental impact: The case of the chemical manufacturing industry

There are two quantitative indicators that are most widely used to assess the extent of compliance of industrial facilities with environmental regulations: the quantity of hazardous waste generated and the amount of toxics released. These indicators, albeit useful in terms of some environmental monitoring, fail to account for direct or indirect effects on human and environmental health, especially when aggregating total quantity of releases for a facility or industry sector. Thus, there is a need for a more comprehensive approach that can prioritize a particular chemical (or industry sector) on the basis of its relevant environmental performance and impact on human health. Accordingly, the objective of the present study is to formulate an aggregation of tools that can simultaneously capture multiple effects and several environmental impact categories. This approach allows us to compare and combine results generated with the aid of select U.S.-based quantitative impact assessment tools, thereby supplementing compliance-based metrics such as data from the U.S. Toxic Release Inventory. A case study, which presents findings for the U.S. chemical manufacturing industry, is presented to illustrate the aggregation of these tools. Environmental impacts due to both upstream and manufacturing activities are also evaluated for each industry sector. The proposed combinatorial analysis allows for a more robust evaluation for rating and prioritizing the environmental impacts of industrial waste.     

Prediction of ultra-high aspect ratio nanowires from self-assembly

We employ a combination of ab initio total energy calculations and classical molecular dynamics (MD) simulations to investigate the possible self-assembly of nanoscale objects into ultrahigh aspect ratio chains and wires. The ab initio calculations provide key information regarding selective chemical functionalization for end-to-end attraction and the subtle interplay of the energy landscape, which is then used to fit classical potentials. MD simulations are carried out to predict short-time dynamical properties of assembly as a function of synthesis conditions, including solvent, chemical functionalization, temperature, and concentration. Our results suggest an efficient technique for bringing nanoscale objects together to form ultrahigh aspect ratio nanowires with high-quality alignment. We show that the electronic structure of the resulting nanowires depends strongly on the end functionalization.     

On the replacement of empirical parameters in multimedia mass balance models with QSPR data

Official OECD recommendations give the highest priority to application of purely empirical phys/chem data (partition coefficients, environmental half-live times etc.) in multimedia mass balance modeling of environmental overall persistence and long-range transport for potentially hazardous chemicals. We have demonstrated that the replacement of the empirical data with those predicted by employing Quantitative Structure-Property Relationships (QSPR) technique did not significantly decrease the performance of The Tool 2.0 - the OECD multimedia mass balance model. To prove this, we compared each other the output results (overall persistence - P_OV; characteristic traveling distance - CTD and transport efficiency TE) obtained from 6 of multimedia models. The models utilized combinations of experimentally determined and QSPR-predicted values of the partition coefficients and half-live times. For predicting phys/chem data, we utilized 2 QSPRs developed in our laboratory and the EPI Suite package (US EPA). We did not observe any statistically significant (p < 0.05) differences between the models. This conclusion is important, because it leads to reducing time and costs of laboratory studies required during the risk assessment procedure. Moreover, regarding the obtained results, we proposed to replace the single-threshold approaches established by majority of international regulations to screen substances for persistence, bioaccumulation and long-range transport potential with the approaches taking into account uncertainty of the results and/or probability of passing a given threshold.     

Static and dynamic properties of the water/amorphous silica interface: a model for the undissociated surface

Amorphous silica–water interfaces are found ubiquitously in nanoscale devices, including devices fabricated from silica as well as from silicon that acquire a surface oxide layer. The surface silanol groups serve as hydrogen-bonding sites for a variety of chemical species, and their reactivity enables convenient chemical modification, making silica surfaces strategic in bio-sensing applications. We have extended the popular BKS and SPC/E models for bulk silica and water to describe the hydrated, hydroxylated amorphous silica surface. The parameters of our model were determined using ab initio quantum chemical studies on small fragments. Our model will be useful in empirical potential studies, and as a starting point for ab initio molecular dynamics calculations. At this stage, we present a model for the undissociated surface. Our calculated value for the heat of immersion, 0.6Jm⁻², falls within the range of reported experimental values of 0.2–0.8Jm⁻². We also study the perturbation of water properties near the silica–water interface. The disordered surface is characterized by regions that are hydrophilic and hydrophobic, depending on the statistical variations in silanol group density. We report non-equilibrium molecular dynamics simulations of Poiseuille flow of water near an amorphous silica surface.     

The underdeterrence,underperformance response to privacy,data protection laws

The digital economy has been defined in the economic literature as one with near zero marginal cost, unmonetized services but also an escalating data flow. After a careful review of the most recent economic papers, we offer an alternative theory on the cost of privacy and data protection regulations. We have observed that the characteristics of the regulation lead not only to the amplification of costs that have been traditionally assigned as variable costs by the literature, but also of costs that used to be fixed but have been outsourced in the digital economy, meaning that significant new variable costs might trigger diseconomies of scale. At the same time, privacy and data protection regulations have created incentives that are making the dominant firms insource, in what seems to be a way back to increased sunk fixed costs for these firms. Having all that in mind, we claim that the perception of deterrence and compliance costs has affected how firms might decide to incur higher risks to avoid costs. Although compliance costs are high, we claim that an efficient implementation of the regulation avoids much of these costs. Our claim is supported by evidence that a relevant share of the regulatory costs are now variable costs, leaving room for at least two efficient strategies that medium-sized firms might implement in order to avoid them. First, firms can lower the volumes of data that they use without significantly impairing the predictive functions of their algorithms. Second, firms can invest in security at a comparatively lower degree than dominant firms considering their lower exposure to strong regulatory action.     

食品接触材料中有害物质迁移的研究进展

目的 综述目前食品接触材料中几种常用材料(纸、塑料、油墨)迁移与检测的研究进展,并指出几种材料未来的发展趋势,促使我国食品行业向着更绿色、更安全的方向发展。方法 概述纸质、塑料、油墨的发展趋势和材料中有害物质的来源;对比几种材料的迁移规律及迁移模型;总结几类常见有害物质的检测方法。结论 绿色环保的生物基材料是食品接触材料未来的发展方向,同时也需重视可持续性生物基食品接触材料的化学安全性。因其产生的化学品对人体健康的影响不甚明朗,因此需多方面研究生物基食品接触材料中化学物质的存在和迁移到食品中的情况,并采取相应措施减少包装材料的使用,降低材料中有毒有害物质对人体和环境的威胁。     

The assessment of community vulnerability to acute hazardous materials incidents

The manufacture, storage and transportation of voluminous quantities of hazardous chemicals in the United States and Canada pose serious problems for lEmergency planners, however, should not merely concern themselves with the physical hazard, “risk”, that confronts them. In developing disaster mitThese more specific analyses should isolate particularly vulnerable neighborhoods and should be applied to areas where emergency-related resources canA regional vulnerability scale should consist of two components. First, a hazard assessment component where such factors as the density of chemical pro     

Opportunities and Challenges of Artificial Intelligence for Green Manufacturing in the Process Industry

Smart manufacturing is critical in improving the quality of the process industry. In smart manufacturing, there is a trend to incorporate different kinds of new-generation information technologies into process-safety analysis. At present, green manufacturing is facing major obstacles related to safety management, due to the usage of large amounts of hazardous chemicals, resulting in spatial inhomogeneity of chemical industrial processes and increasingly stringent safety and environmental regulations. Emerging information technologies such as artificial intelligence (AI) are quite promising as a means of overcoming these difficulties. Based on state-of-the-art AI methods and the complex safety relations in the process industry, we identify and discuss several technical challenges associated with process safety: ① knowledge acquisition with scarce labels for process safety; ② knowledge-based reasoning for process safety; ③ accurate fusion of heterogeneous data from various sources; and ④ effective learning for dynamic risk assessment and aided decision-making. Current and future works are also discussed in this context.     

Molten salts safety and hazards: An annotated bibliography

The present information was compiled as a guide to good practice and as an aid in discovering potentially dangerous situations with molten salts in research and technology, and is based on a survey of the primary, secondary, and tertiary scientific literature to December, 1976. The format of an annotated bibliography was selected for this communication; the results are reported with reference to nine categories: hazards; reactive chemical hazards; dangerous mixtures of inorganic compounds; potentially hazardous metal—molten salts mixtures; precautions; applications of molten salts in process design and technology; water in melts; water solubility data; and reviews. A systems index is included. Titles of selected publications are included in the list of references as an additional aid to the user (196 references).     

Models of mechanisms for the vapor phase emission of hazardous chemicals from landfills

Quantities of hazardous chemicals have been placed in sanitary landfills in conjunction with solid waste. This paper presents three vapor phase transport mechanisms: molecular diffusion, bio-gas convection, and barometric pressure pumping. These mechanisms are incorporated into a dynamic model that simulates the emission flux rate of chemicals, as a function of landfill and environmental variables. The simulation model is driven by time-varying atmospheric pressure fluctuations. Darcy's law is used to simulate gas movement through the landfill cap material to and from the landfill cells. With all mechanisms operative, a rate of 290 g benzene/m² d was obtained from the model using benzene as a test chemical. Atmospheric pressure fluctuations pump toxic vapors and gases from the storage cells of hazardous waste landfills to the air above. This pumping enhances the vapor phase molecular diffusion process. The calculated benzene flux rate with diffusion and atmosphere pumping was 13 g/m² d. Uncertainties and limitations of the model are considered which include: vapor and gas circulation in and between cells, adsorption onto solids and multi-cell landfills. The model presented is a practical tool for initial evaluation studies of volatile chemical emissions from landfills and provides a basis upon which to construct more realistic simulation models.