A study of the precursors leading to ‘organisational’ accidents in complex industrial settings

This study aggregates the narrative findings from the investigation of 12 accidents or ‘near hits’ across a wide range of industrial settings to build a catalogue of organisational and cultural precursors to accidents. It was found that many were important factors in multiple events. It is argued that by addressing these potential vulnerabilities using the findings and proposed tools based upon them, organisations undertaking safety related activities will not only develop greater awareness of these deeper-lying issues but should be able to better control the risks associated with them.The precursors have been classified under eight headings and examples of key findings from three of these are presented. Statements providing potential defences against the identified vulnerabilities have been developed which should enable organisations to scrutinise the adequacy of existing expectations or requirements within their business. Probing questions have been developed based on the statements which should allow an assessment to be made as to whether these have been ‘embedded’ in the organisation.It is argued that organisational vulnerability tools should be developed to enable a systematic approach to ‘diagnosing’ incubating precursors. It is also argued that there is the potential for further resilience to be achieved through the use of models of the complex dynamics of socio-technical processes within organisations.     

Accidents in the chemical industry: are they foreseeable?

‘Accidents recur,’ which is what Kletz [Kletz T. (1993). Lessons from disasters, how organisations have no memory and accidents recur. UK: Institution of Chemical Engineers] wrote in 1993. Indeed, despite all measures taken accidents may re-occur, but ‘disruptions’ in a process reoccur much more frequently. If a disruption occurs it may lead to an accident. If the same disruption reoccurs it is certainly suspect and should be considered as a potential precursor. In this paper, we concentrate on these disruptions and we will define them as precursors if they recur. Organizations somehow lack the ability to control such recurring disruptions that may escalate into serious accidents under certain circumstances. The presence of such precursors long before the occurrence of an accident raises doubts about how well organizations control safety.In this paper, the control mechanism inside organizations is examined, by means of several accident investigations. It will be shown that not only accidents recur, but also that disruptions recur in a period preceding the actual accident. The recurrence of these disruptions implies that the corresponding organizational control mechanism must be failing. Often, alternative circumstances prompt the escalation of such precursors and lead to actual accidents. It is demonstrated that the use of detailed accident information is of great importance for companies that are actually willing to prevent accidents through the elimination of disruptions preceding accidents.     

“数字化集中仓”模式下危化品仓储安全监管的演化博弈分析*

针对利用数字化技术提高危化品仓储安全监管水平问题,考虑政府搭建“危化品集中式仓储中心+数字化网络监管平台”策略,基于演化博弈理论,构建危化品仓储安全监管演化博弈模型,分析建立数字化集中仓概率（本文简称“建仓概率”）对相关政府部门和危化品仓储企业行为演化规律的影响,探讨数字化集中仓模式下,危化品仓储企业合规仓储的驱动因素。研究结果表明:当建仓概率低于某临界值时,政府部门和危化品仓储企业会疏于监管违规仓储;随着建仓概率提高,政府部门和危化品仓储企业策略呈现周期性波动现象;当建仓概率很高时,虽然数字化集中仓一定程度上可提高政府监管便利性,但从长远看会使政府监管部门放松对危化品仓储安全的监管。研究结果可为政府推行数字化监管新模式和危化品仓储企业实施智能仓储管理提供一定决策支持。     

Dynamic risk assessment using failure assessment and Bayesian theory

To ensure the safety of a process system, engineers use different methods to identify the potential hazards that may cause severe consequences. One of the most popular methods used is quantitative risk assessment (QRA) which quantifies the risk associated with a particular process activity. One of QRA's major disadvantages is its inability to update risk during the life of a process. As the process operates, abnormal events will result in incidents and near misses. These events are often called accident precursors. A conventional QRA process is unable to use the accident precursor information to revise the risk profile. To overcome this, a methodology has been proposed based on the work of Meel and Seider (2006). Similar to Meel and Seider (2006) work, this methodology uses Bayesian theory to update the likelihood of the event occurrence and also failure probability of the safety system. In this paper the proposed methodology is outlined and its application is demonstrated using a simple case study. First, potential accident scenarios are identified and represented in terms of an event tree, next, using the event tree and available failure data end-state probabilities are estimated. Subsequently, using the available accident precursor data, safety system failure likelihood and event tree end-state probabilities are revised. The methodology has been simulated using deterministic (point value) as well as probabilistic approach. This Methodology is applied to a case study demonstrating a storage tank containing highly hazardous chemicals. The comparison between conventional QRA and the results from dynamic failure assessment approach shows the significant deviation in system failure frequency throughout the life time of the process unit.     

危险化学品的信息化、智能化监管

为提升危险化学品行业的整体安全水平,减少运输装卸、储存保管和使用等环节的安全隐患,利用物联网、地理信息化、云计算、大数据等先进技术,建设危险化学品监管信息化平台,采用智能化、信息化的监管模式,有助于危险化学品管理,减少事故发生。这种主动式、精细化、智能化的安全监管,是危险化学品监管的发展方向。     

危险化学品仓储存在的问题和安全对策

危险化学品仓储是一种特殊商品的仓储,存在较大的事故隐患.作为危险化学品全寿命周期的一部分,仓储安全管理工作非常重要.针对危险化学品仓储管理中存在的问题,结合我国实际情况,参照国外先进的管理模式,提出了危险化学品仓储安全的要求.     

“Like it’s wrong,but it’s not that wrong:” Exploring the normalization of risk-compensatory strategies among young drivers engaging in illegal smartphone use

Introduction: Young drivers are the most vulnerable road users and most likely to use a smartphone illegally while driving. Although when compared with drink-driving, attitudes to illegal smartphone risk are nearly identical, smartphone use among young drivers continues to increase. Method: Four in-depth focus groups were conducted with 13 young (18–25 years) drivers to gain insight into their perceptions of the risks associated with the behavior. Our aim was to determine how drivers navigate that risk and if their behavior shapes and informs perceptions of norms. Results: Three key themes emerged: (a) participants perceived illegal smartphone use as commonplace, easy, and benign; (b) self-regulatory behaviors that compensate for risk are pervasive among illegal smartphone users; and (c) risk-compensation strategies rationalize risks and perceived norms, reducing the seriousness of transgression when compared with drink-driving. Young drivers rationalized their own use by comparing their selfregulatory smartphone and driving skills with those of “bad drivers,” not law abiders. Practical Applications: These findings suggest that smartphone behaviors shape attitudes to risk, highlighting the importance for any countermeasure aimed at reducing illegal use to acknowledge how a young person’s continued engagement in illegal smartphone use is justified by the dynamic composition of use, risk assessment and the perceived norms.     

对天津港“8·12”特别重大火灾爆炸事故相关法规标准的思考

硝化棉已分别列入危险化学品、易制爆危险化学品和第二批重点监管的危险化学品,硝酸铵也分别列入危险化学品、民用爆炸物品和首批重点监管的危险化学品,二者都是重点监管的对象,但二者相关事故还是时有发生。为了更全面和深刻理解天津港“8·12”特别重大火灾爆炸事故的发生,以危险化学品储存场所外部距离标准要求为切入点,分析了储存场所外部距离变化过程;介绍了初始起火物质硝化棉和导致事故后果严重扩大的硝酸铵2种危险化学品的国内监管分类和相关标准要求,并与事故调查报告中给出的结论进行了对比;针对本起火灾爆炸事故后果特点和非法储存危险物质罪罪行认定条件,剖析了现存的问题。分析结果旨在为政府有关部门及事故调查等工作提供参考。     

The effects of activated Al2O3 on the recycling of light oil from the catalytic pyrolysis of waste printed circuit boards

The effects of employing activated Al₂O₃ during the catalytic pyrolysis of waste printed circuit boards (WPCBs) are investigated, focusing on the recycling of light oil. Variations in the pyrolysis process are studied through analysis of the phase distribution, water content and boiling point fractions of the resulting products. Product composition and carbon number distribution are analyzed using gas chromatography techniques. The use of activated Al₂O₃ increases the light oil fraction and also reduces the quantity of brominated products formed. It was determined that the best yield of light oil and most efficient debromination resulted from catalytic pyrolysis at 600 °C. Applying catalyst-to-feed ratios in the range of 1.0–1.5 also maximizes the yield of light oil. The major oil fraction resulting from catalytic pyrolysis has a boiling point range of 0–250 °C and carbon number range of C6–C9, showing for use as a potential fuel after suitable treatment such as hydrogenation. At a higher catalyst-to-feed ratio of 2.0, activated Al₂O₃ generates a high proportion of light oil fractions containing a significant quantity of chemicals such as phenol (52.67% at 600 °C), although an overall lower yield of oil is obtained. The oil produced in this manner may also be used as a raw material feedstock for the production of various other useful chemicals.     

Assessment of hazardous material risks for rail yard safety

This paper illustrates the application of quantitative risk assessment in a rail yard where tank cars of hazardous materials are received and stored. The assessment was conducted in response to community concerns about the safety of a proposed yard expansion. Six different chemicals are involved. For each one, the average monthly volume and the hazard of most concern are specified. We use an event tree populated with empirical data to compute the probability of a major spill in each case and we estimate the corresponding critical impact distances using available modeling tools. We find that for some of the chemicals, the relative increases in risk are appreciable, but that in all cases, the absolute levels of risk remain low. Then we identify some ways in which such an analysis can be extended and discuss the potential difficulties associated with these extensions.     

Precursor-based hierarchical Bayesian approach for rare event frequency estimation: A case of oil spill accidents

Due to a scarcity of data, the estimate of the frequency of a rare event is a consistently challenging problem in probabilistic risk assessment (PRA). However, the use of precursor data has been shown to help in obtaining more accurate estimates. Moreover, the use of hyper-priors to represent prior parameters in the hierarchical Bayesian approach (HBA) generates more consistent results in comparison to the conventional Bayesian method. This study proposes a framework that uses a precursor-based HBA for rare event frequency estimation. The proposed method is demonstrated using the recent BP Deepwater Horizon accident in the Gulf of Mexico. The conventional Bayesian method is also applied to the same case study. The results show that the proposed approach is more effective with regards to the following perspectives: (a) using the HBA in the proposed framework provides an opportunity to take full advantage of the sparse data available and add information from indirect but relevant data; (b) the HBA is more sensitive to changes in precursor data than the conventional Bayesian method; and (c) using hyper-priors to represent prior parameters, the HBA is able to model the variability that can exist among different sources of data.     

化学品危险性鉴别分类技术研究

从涉及化学品物理危险性的爆炸性测试技术、燃烧性测试技术、氧化性测试技术分析出发,全面深入地讨论化学品危险性测试技术的工作模式、测试程序及各种测试方法的相互关联性和适用性。针对化学品的健康、环境危险性,提出应采用非脊椎动物测试技术,并对涉及化学品危险性鉴别分类技术中一些具有发展潜力的非测试技术进行归纳和分析,指出化学品危险性鉴别分类技术应重点开展清洁高效、智能探测、快速准确鉴别分类技术方面的研究,因此,如何灵活高效地运用现有的鉴别分类测试技术具有重要的意义。     

International co-operation in hazardous materials accident prevention

Accident prevention relies on a proper understanding of relevant hazards so that appropriate controls can be put in place to safeguard those who are potentially endangered. Setting deaths from war, natural events and domestic accidents to one side, industrial chemicals in their manufacture, transport, storage and use arguably contribute significantly to society's accident toll. National and international regimes have been developed over the years to characterise the properties of these hazardous materials so that risks to society and workforces handling such `dangerous goods' are reduced. Sometimes it has taken a disaster to show that a hazard formerly unrecognised did in fact exist; sometimes the closer scrutiny of test methods has shown that a dangerous property may have gone unrecognised; sometimes misuse of materials precipitated controls. However, in all the deliberations surrounding hazardous materials characterisation, accident investigation and prevention, and development of controls, suitable exchange of information and viewpoints between experts is necessary to promote development and adoption of international conventions. These international protocols are normally agreed by policy makers who have technical advisers to support their negotiations. These technical advisers need to meet in an appropriate forum to develop an understanding of all the relevant factors and to test ideas; often such group discussions pave the way to agreements being reached at formal policy negotiations, to solutions being provided for certain disasters, to better methods of testing. The International Group of Experts on the Explosion Risks of Unstable Substances (OECD-IGUS) created by the OECD is one such group. It first met in 1962.Set up initially to harmonise test methods used by countries to identify and quantify the explosive properties of unstable materials, it has continued over the years to offer scientists who are advisers to their governments (and others) a forum to exchange data and information primarily in support of the development of classifications regimes to protect society from the hazards of unstable substances and remove barriers to international trade but also in understanding and quantifying the resulting effects—such as explosion—from accidents involving these and other `dangerous goods'. This paper describes some of the accidents which show the need for international controls for `dangerous goods' and some of the contributions made by OECD-IGUS (often referred to as `IGUS') to their developments.     

对高校化学品储存及使用管理的探讨

化学储存与使用不当易引发事故,造成环境污染。高校化学品使用较多,因此其使用方法及管理不容忽视。对高校化学品储存及使用管理进行了探讨。分析表明,因为高校化学品储存地点分散,使用人员较多,存在着一定的事故隐患,加上部分高校条件较差,使用过的化学品直接排放到环境中,因此,还存在着环境污染问题。应制定有效的管理制度,加强高校化学品的储存及使用管理。     

零星危险化学品快递运输风险博弈分

针对零星危险化学品运输中的安全隐患问题,应用博弈理论构建了政府、快递企业、零星危险化学品托运人的三方博弈模型,对零星危险化学品安全运输问题进行了研究。在求得博弈模型均衡解的基础上,对均衡解进行了深入分析,研究结果表明:政府的最优检查概率与快递企业的安全管理成本正相关,与快递企业发生事故时的损失负相关;快递企业实施安全管理的概率与政府对快递企业的惩罚、快递企业发生事故时政府的损失正相关,与政府的检查成本、托运人选择托运且安全运输时的收益负相关;托运人选择托运的概率与快递企业实施安全管理的成本正相关。最后为有效杜绝零星危险化学品运输事故的发生提出了相应对策。     

Risk assessment of rare events

Rare events often result in large impacts and are hard to predict. Risk analysis of such events is a challenging task because there are few directly relevant data to form a basis for probabilistic risk assessment. Due to the scarcity of data, the probability estimation of a rare event often uses precursor data. Precursor-based methods have been widely used in probability estimation of rare events. However, few attempts have been made to estimate consequences of rare events using their precursors. This paper proposes a holistic precursor-based risk assessment framework for rare events. The Hierarchical Bayesian Approach (HBA) using hyper-priors to represent prior parameters is applied to probability estimation in the proposed framework. Accident precursor data are utilized from an information theory perspective to seek the most informative precursor upon which the consequence of a rare event is estimated. Combining the estimated probability and consequence gives a reasonable assessment of risk. The assessed risk is updated as new information becomes available to produce a dynamic risk profile. The applicability of the methodology is tested through a case study of an offshore blowout accident. The proposed framework provides a rational way to develop the dynamic risk profile of a rare event for its prevention and control.     

Wet bench reactive hazards of cleaning stages in semiconductor manufacturing processes

According to the research from FM Global (Factory Mutual Insurance Company), most of the incidents that have occurred in semiconductor plants in the past two decades were reported as “Fire Cases”. They claim that the fires in wet chemical cleaning processes were mainly caused by heater failure. However, depending on the process conditions, electrical heaters are designed to turn off automatically when the temperature reaches a set point. Therefore, a thorough study of the situations related to possible fires in wet chemical cleaning processes is necessary.

This study focused on the incompatible behaviors of cleaning materials used in the wet bench stage. These results can be applied to determine the causes of fires in the wet bench stage from using reactive chemicals for cleaning purposes.

Another purpose of this study was to investigate the potential hazards of widely used chemicals (hydrogen peroxide, concentrated sulfuric acid, hydrochloric acid and isopropyl alcohol) within similar processes in semiconductor plants. Experimental data were also verified in order to establish a concentration triangular diagram, which could be used to identify a combustion, deflagration or even detonation zone. Finally, this study can provide basic design data for an inherently safer process to avoid potential hazards caused by dangerous mixtures, which may result in large property loss in semiconductor plants.     

化学品混合物的安全监管技术研究

从分析我国化学品混合物安全监管技术出发,研究对比我国和国外在化学品混合物的危险性鉴别与分类、命名以及名录收入形式等安全监管技术方面的不同做法;指出我国在混合物危险性鉴别与分类、命名以及名录收入形式方面的缺陷和不足;提出完善化学品混合物安全监管技术是提高我国化学品混合物安全监管水平的重要手段;认为借鉴欧盟RAECH、联合国《关于危险货物运输的建议书-规章范本》及GHS的先进做法制定化学品混合物技术名称命名规则、修订现行危险化学品名录中混合物条目、引进混合物健康及环境危害估算方法,对提高我国化学品混合物的安全监管技术水平,促进化学品混合物的安全监管具有重要现实意义。     

有毒化学品泄漏事故应急防护行动决策探讨

当发生有毒化学品泄漏事故时,为保护公众和工人的安全和健康,需要快速地选择合适的应急防护行动.通常采用的应急防护行动有疏散、隐蔽、使用个人防护装备和服用解毒剂等.决策者必须权衡大量影响因素间的相互作用,如化学品的释放特征、事故现场的气象条件及影响范围内的人群分布等来进行应急防护行动决策.本文在分析应急防护行动决策过程关键要素的基础上,详细总结了影响应急防护行动决策的因素,介绍了应急决策常用的方法,以便在有毒化学品泄漏事故的应急过程中有效决策,最大限度地减少人员伤亡.