Simple graphical method for inherent occupational health assessment

The concept of inherently safer design was introduced to design a fundamentally safer process so that hazards can be avoided or minimized rather than controlled or managed. The ideology has later been extended to the environmental, but not health criteria due to its complicated underlying principles. Even though health risk methods are already established, majority are for existing plants assessment. Early consideration of health aspect starting from process design stage however, has received much less attention. This paper introduces a simple graphical method to evaluate the inherent occupational health hazards of chemical processes during the R&D stage. A survey was conducted to identify the important health parameters for the graphical method development, involving nine world inherent safety and health experts. Based on their input, process mode, material volatility, operating pressure and chemical health hazard (toxicity and adverse effect) are the significant factors affecting inherent health hazards of chemical processes. The choice of parameters was bounded by the information availability at this stage. The method was applied on six routes to methyl methacrylate and ten routes to acetic acid. The parameters were plotted for each subprocess of the alternative routes. The ‘healthiest’ route was selected based on thorough hazards assessment across all the subprocesses. The first case study reveals the tertiary butyl alcohol as the ‘healthiest’ one as it poses relatively lower, or at least comparable hazards to the other routes due to exposure and health impacts. Meanwhile the acetic acid case study indicates ethanol oxide and ethyl oxide based routes as the inherently healthier as they operate at lower operating pressure besides posing comparable hazards level for the other three parameters, compared to the other routes. The case studies show that the inherent occupational health of a chemical process can already be evaluated easily in the R&D stage with the simple graphical method proposed.     

Inherent occupational health assessment during process research and development stage

Occupational health studies the interaction of work and health, especially the long-term effect of chemicals to health. In this paper an Inherent Occupational Health Index has been developed for assessing the health risks of process routes during process research and development stage. The method takes into account both the hazard from the chemicals present and the potential for the exposure of workers to the chemicals. The index can be used either for determining the level of inherent occupational health hazards or comparing alternative process routes for these risks. The method is tailored for the process research and development stage by including only such properties of chemicals and operating conditions of process, which are available already in this early stage. In the end of this paper the approach is demonstrated by comparing the inherent occupational healthiness of six methyl methacrylate process routes using three different types of index calculations; additive-type, average-type, and worst case-type. The study discloses that the average- and worst case-based approaches analyze the characteristics of a route better than the additive calculation, which is greatly affected by the number of steps in the route. A quantitative standard scale for the index is also developed to allow health level assessment of a single process.     

Computer-aided assessment of occupationally healthier processes during research and development stage

Each year more people die from occupational related diseases than are killed in industrial accidents. Therefore it is critical to start considering health aspect early when developing a new chemical process. In this paper, a computer-aided tool for assessing inherent occupational health is proposed for chemical process research and development stage. The method was developed based on the reaction chemistry data, which is the only data available at this stage. Three types of approaches were formulated to calculate the route index value using additive type, average type and worst case type calculations. The tool can be used to rank the alternative chemical synthesis routes by their health properties as well as characterize the hazard level of single process. Finally the tool was applied to six process routes for methyl methacrylate production for demonstration. The case study revealed hazards of the processes from different perspectives, e.g. the results from the additive-type calculation were mainly affected by the total number of steps in the route, which indicates the impact of process complexity on the level of hazard. The introduction of such tool provides a swift yet reliable means that will encourage health criteria to be considered earlier in process development besides economic, safety and environment.     

化工过程开发中本质安全化设计策略

本质安全化设计是预防人为失误及设备失效、降低化工过程风险应优先采用的技术。在比较传统设计方法与本质安全化设计方法的基础上,讨论了化工过程开发各阶段实现本质安全的机会,认为在开发初期,实施本质安全化的成本低,难度小;通过分析可行性研究、工艺研究、概念设计、基础设计、工程设计等阶段本质安全化设计的影响因素、设计目标和设计方法,探索化工过程开发中本质安全化设计策略,提出了化工过程本质安全化设计流程。通过工艺过程本质安全设计、工艺流程的简化和优化、不同设计方案的本质安全度评估等措施,可提高化工过程本质安全水平。     

基于本质安全的化工工艺物质危险指数研究

建立了基于本质安全的化工工艺物质危险性的评价体系,包括火灾危险性、爆炸危险性以及毒性等3个评价指数.基于风险的思想,各个评价指数均包括概率指标与后果指标.为了全面反映化工工艺的实际情况,在各个评价指数中均对所有物质的相应指数值加和.参数的取值以以往的指数法为基础,为了消除边界波动效应,取值采用内插法.由于各个指数的量纲...     

Chemical process route selection based upon the potential toxic impact on the aquatic,terrestrial and atmospheric environments

This paper proposes a method to estimate the inherent environmental friendliness of a chemical process plant by considering the potential toxicity impact on the aquatic, terrestrial and atmospheric environments. A worst-case scenario of a total loss of containment in the plant is assumed. The method proposed by [Gunasekera, M.Y., Edwards, D.W. (2003). Estimating the environmental impact of catastrophic chemical releases to the atomosphere: an index method for ranking alternative chemical process routes. Trans. IChemE., Part B, Process Safety and Environmental Protection, 81(B6), 463–474] for determining the inherent atmospheric environmental friendliness of a chemical plant is combined with the method proposed by [Cave, S.R., Edwards, D.W. (1997). Chemical process route selection based on assessment of inherent environmental hazard. Computers Chem. Engng., 21, S965–S970], which estimates the inherent friendliness to the aquatic and terrestrial environments.Application of this method to six routes to produce methyl methacrylate shows that the acetone cyanohydrin based route is potentially the least inherently environmentally friendly. The highest potential hazard is observed in the aquatic environment due to the chemicals associated with the acetone cyanohydrin route.     

基于集对分析的化工工艺本质安全性评价方法

为了提高化工工艺本质安全性评价的有效性和全面性,根据集对分析理论建立了四元联系数评价模型。模型选用传统的本质安全指标及其分级标准,对各指标进行赋权,以甲基丙烯酸甲酯合成工艺路线为例进行实用性验证,最终确定了多条工艺路线的本质安全程度优劣顺序,并明确各自的本质安全程度。结果表明,集对分析方法能够客观全面地评价化工工艺路线的本质安全性,可以用于化工工艺路线的优选过程,为工艺安全管理和技术改进提供指导。     

Comparison of inherent safety indices in process concept evaluation

In conceptual design, process routes can be compared and ranked by using inherent safety indices. In this paper, some inherent safety index methods presented in literature are compared and their properties and limitations discussed. As a case study, an inherent safety evaluation of methyl methacrylate process routes is presented. Three index based inherent safety evaluation methods are compared with expert evaluations on methyl methacrylate process routes and their subprocesses. Also the index based inherent safety ranking of process routes is compared with an expert ranking.     

化学品危险性鉴别分类研究的现状与展望

从对GHS(化学品分类及标记全球协调制度)化学品危险性鉴别分类的分析出发,归纳和总结了联合国、欧盟、美国以及中国的化学品危险性鉴别分类研究现状;提出化学品危险性鉴别分类是获取化学品安全信息、评估化学品的固有危险性的重要手段;给出化学品危险性鉴别分类试验必须满足OECD(经济合作与发展组织)的各项标准和准则;对化学品危险性鉴别分类的应用前景及未来工作进行评述和展望;指出为化学品安全管理、事故应急救援、事故调查及做好基础数据的积累是今后研究工作的努力方向;提出了借鉴GHS,REACH(化学品注册、评估、许可和限制)等先进化学品安全监管法规,对完善我国的化学品安全监管制度,化学品鉴别分类标准的重要现实意义。     

Occupational chemical exposure and risk estimation in process development and design

Each year more people die from diseases caused by work than are killed in industrial accidents. Therefore, methods are needed to evaluate occupational health hazards as early as possible when the process is still under development. A method for estimating inhalative exposures and risks in petrochemical and related plants is presented. The method is simple and suffices with the limited data availability during the early design stages.The steps of the method, which utilizes preliminary process flow diagrams are as follows: first the fugitive emissions and process plot areas are estimated based on precalculated process modules representing the typical process sections (such as a distillation unit). Chemical concentration in the air is then calculated based on the wind velocity probability and the estimated process cross-sectional area. For this purpose a typical wind velocity distribution in the area is used. The worker risk of exposure to chemicals is evaluated either based on the concentration in air by using the hazard quotient method or calculating the carcinogenic chemicals intake and the resulting risk of cancer. The values are compared to the benchmarks.As a result the process route health characteristics such as fugitive emissions rate, critical wind speed, chemical concentration in air and intake amount as well as the corresponding risk of exposure are produced. By using statistical meteorological data, health risks of occupational exposure can be estimated more realistically as probabilities. The approach is capable of comparing alternative processes to select the concept which is inherently occupationally healthier. Using this method, the exposure problems of a process can be identified earlier and proper decisions can be made early in process development or predesign stage.The concentration-based method is demonstrated by a case study of six competing manufacturing routes for methyl methacrylate (MMA). The C3 is found to be the most harmful alternative to health. Both concentration-based and intake-based methods are applied. The study indicates that the intake-based risk estimation benchmark is stricter than the exposure limit-based benchmark for carcinogens.     

Development of inherent safety and health index for formulated product design

The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method.     

基于模糊综合评价的化工工艺本质安全指数研究

建立化工工艺的本质安全评价指标体系,包括可燃性、爆炸性、毒性、反应性、温度、压力、储量等7个指标。为解决前人指数法中的边界波动效应,采用模糊综合评价建立化工工艺本质安全评价指数模型,确定各指标的权重、危险分级及对各分级的隶属函数。以甲基丙烯酸甲酯的5条工艺路线为例进行分析,结论与前人提出的指数方法的评价结果相吻合,表明该指数方法可以用来进行化工工艺的本质安全评价,以指导设计初期的本质安全型工艺路线选择。     

Inherent safety in offshore oil and gas activities: a review of the present status and future directions

Inherent safety is a proactive approach for hazard/risk management during process plant design and operation. It has been proven that, considering the lifetime costs of a process and its operation, an inherently safer approach is a cost-optimal option. Inherent safety can be incorporated at any stage of design and operation; however, its application at the earliest possible stages of process design (such as process selection and conceptual design) yields the best results.Although it is an attractive and cost-effective approach to hazard/risk management, inherent safety has not been used as widely as other techniques such as HAZOP and quantitative risk assessment. There are many reasons responsible for this; key among them are a lack of awareness and the non-availability of a systematic methodology and tools.The inherent safety approach is the best option for hazard/risk management in offshore oil and gas activities. In the past, it has been applied to several aspects of offshore process design and operation. However, its use is still limited. This article attempts to present a complete picture of inherent safety application in offshore oil and gas activities. It discuses the use of available technology for implementation of inherent safety principles in various offshore activities, both current and planned for the future.     

Supporting the selection of process and plant design options by Inherent Safety KPIs

Effective support of inherent safety implementation in process design requires a quantitative metric for monitoring and communicating the expected safety performance of alternative design options. The Inherent Safety Key Performance Indicators (IS-KPIs) methodology was developed to provide both a flexible procedure for the identification of the hazards, and a sound consequence-based quantification of the safety performance. The integration of different hazard identification techniques yields the relevant accident scenarios for each unit in the plant. The calculation of credible damage distances by consolidate consequence simulation models provides a sound basis for the definition of the KPIs based on worst case effects. Specific indicators were devoted to hazards from external actions, as natural events and intentional malicious acts. The methodology was demonstrated by the comparison of alternative technological options for LNG regasification. The application evidenced the potential of the IS-KPI method in pinpointing the critical issues related to each alternative configuration.     

Strategies for assessing and reducing inherent occupational health hazard and risk based on process information

Over the last few decades, the concept of inherent occupational health has gained increasing attention to reduce occupational hazards that may adversely impact workers’ health. In order to assess occupational hazards in the chemical process, different inherent occupational health assessment methods have been developed at the early stages of process development and design. The methods in the order of process information availability – ranging from the detailed piping and instrumentation diagrams to a simple sketch of process concepts are the: occupational health index (OHI), health quotient index (HQI) and inherent occupational health index (IOHI). This paper proposes systematic heuristic frameworks to assist process designers and engineers in assessing and reducing inherent occupational health hazards or risks based on process information availability. Strategies for reducing health hazards or risks in the OHI, HQI and IOHI methods based on inherently safer design (ISD) keywords of minimization, substitution, moderation and simplification are included in this study. It is worth mentioning that the proposed frameworks act as guidelines for design engineers in systematically selecting the appropriate index and methodology to assess and reduce health hazards/risks based on the availability of the process information. A case study is solved to illustrate the proposed framework.     

What can the trove of CSB incident investigations teach us? A detailed analysis of information characteristics among chemical process incidents investigated by the CSB

Understanding the commonalities among previous chemical process incidents can help mitigate recurring incidents in the chemical process industry and will be useful background knowledge for designers intending to foster inherent safety. The U.S. Chemical Safety and Hazard Investigation Board (CSB) reports provide detailed and vital incident information that can be used to identify possible commonalities. This study aims to develop a systematic approach for extracting data from the CSB reports with the objective of establishing these commonalities. Data were extracted based on three categories: attributed incident causes, scenarios, and consequences. Seventeen causal factors were classified as chemical indicators or process indicators. Twelve chemical indicators are associated with the hazards of the chemicals involved in the incidents, whereas five process indicators account for the hazards presented by process conditions at the time of the incident. Seven scenario factors represent incident sequences, equipment types, operating modes, process units, domino effects, detonation likelihood for explosion incidents, and population densities. Finally, three consequence factors were selected based on types of chemical incidents, casualties, population densities, and economic losses. Data from 87 CSB reports covering 94 incidents were extracted and analyzed according to the proposed approach. Based on these findings, the study proposes guidelines for future collection of information to provide valuable resources for prediction and risk reduction of future incidents.     

基于筛选测试的化工反应危害评估探讨

本文主要讨论了基于筛选测试方法的化工反应危害评价。该方法是利用DSC、TS“等差热分析仪对化学品和混合物进行热稳定性的筛选测试，根据起始温度和反应焓变对化合物危害程度分级进行分级，建立反应风险指数，从而在小试和中试阶段就将反应危害降低或消除，确保大规模生产时的安全性，为真正实现化工工艺本质安全。此外，还比较了DSC、TSU、AFFAC、RSST等热分析仪，认为TSU和RSST是目前较为合适的热筛选分析仪，为建立反应危害实验室相关仪器的选型提供了参考。     

化工过程本质安全性之模糊评价系统

在综合分析化工过程构成的基础上,建立的化工过程本质安全性评价指标,借鉴国内外本质安全评价的研究,应用Matlab模糊推理系统,以评价指标的等级划分、隶属度函数设计及推理规则设定等为主线,建立化工过程本质安全性模糊评价系统,实现评价指标和评价推理结果的可视化。通过甲苯高温加氢脱烷烃制取苯的工艺过程,实施不同工艺路线及其操作条件改变的本质安全性评价,验证了所建立模糊评价系统的可行性。研究结果对指导化工安全设计和安全评价、减少和消除重大危险源,进一步提升我国化工行业的整体安全水平具有重要的理论和现实意义。     

化工园区安全监控系统研究

化工园区内重大危险源数量多、密度大,存在着发生重特大事故的现实性和可能性。因此,亟需建立化工园区安全监控系统对化工园区内的固定危险源、危险工艺过程、危化品车辆和公共区域重要部位进行动态监控和安全监管,预防和消除事故风险,并为化工园区安全监控与事故应急提供技术支持。提出了化工园区安全监控系统系统硬件架构,介绍了化工园区安全参数设置方法、安全监控流程和事故预警机制,提出了系统软件的总体架构和功能。