Estimation of chemical concentration due to fugitive emissions during chemical process design

Fugitive emissions are not an environmental concern alone, but are also a health concern. From occupational health standpoint, fugitive emissions are the main sources of origin of the continuous exposure to workers. Operating plants regularly measure release and concentration levels through a plant-monitoring program. However, for processes which are still ‘on paper’, predictive estimation methods are required. Therefore, three methods for estimating concentration of the fugitive emissions are presented for the process development and design phases of petrochemical processes. The methods estimate the fugitive emission rates and plant plot dimensions resulting to fugitive emission concentrations. The methods were developed for the type and amount of information available in three process design stages; conceptual design, preliminary process design, and detailed process design. The methods are applied on a real benzene plant; the estimated benzene concentrations are compared to the actual concentration measured at the plant. The results show that as the information mounts up during design, the concentration estimate becomes more accurate. The results indicate that the methods presented provide simple estimates of fugitive emission-based concentrations during the design stages.     

Inherent occupational health assessment during preliminary design stage

Chemical process routes can already be assessed as early as in the development and design phases. Process screening should not look at economic and technical aspects only, but also the safety, health, and environmental performances. In this paper, a method called the Health Quotient Index (HQI) is presented for the preliminary process design phase. The HQI provides a simple approach to quantify workers' health risk from exposure to fugitive emissions e.g. in petrochemical plants. The method utilizes process data from flow sheet diagram, which is already available at the preliminary design stage. Since the mechanical details of the process are still unknown, a database of the precalculated fugitive emissions for typical operations in chemical plants was created to simplify the assessment. The HQI can be used to rank alternative process concepts or to quantify the risk level of processes. As a case study, six process routes for producing methyl methacrylate are discussed. Three health indexes are compared in the case study. The HQI is able to highlight the difference of hazard levels between the routes better as a result of more detailed assessment of the exposures.     

Fugitive emissions in chemical processes: The assessment and prevention based on inherent and add-on approaches

Fugitive emissions are among the major concerns of industrial process releases. The emissions cause problem to various aspects including the environment, health, and economic. Early evaluation of process hazards is beneficial because process can be made inherently benign at lower cost. This paper discusses two important aspects of fugitive emissions assessment during process design – the quantification and the prevention strategies.For the quantification part, three methods are presented for fugitive emissions estimation during the process design. They are tailored to data available in simple process flow diagram (PFD), detailed PFD, and piping & instrumentation diagram (PID). Such methods are needed as early emissions estimation allows production routes and process designs with lower emissions to be selected. The fugitive emissions estimation and methods to abatement are demonstrated on a benzene process case study. Valves are found to be the major emission source with 50% of fugitive emissions of process area in a base case of petrochemical process, in which no fugitive emission reductions are yet made. Pumps without mechanical seals come second with 30% and flanges with 8% of emissions. Inherently safer design keywords can be applied to prevent fugitive emissions in the process plants. Substitution is the most applicable keyword in fugitive emission reduction of existing plants.The emission rate calculations together with estimation of health risk give a sound background for the decision making on elimination of emissions at source through equipment and piping changes. The case study presented reveals that by substituting emission prone components by inherently low-leaking ones, the plant emissions can be reduced over 90% in practice. This is created mainly by replacing rising stem valves with ball valves, installing double mechanical pump seals or hermetic pumps and making changes in sampling and relief systems. Ideally by also changing flanges to welded connections, which is not viable for various reasons, the emissions could be reduced nearly to zero.     

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.     

电子封装行业化学有害因素职业暴露评价

以法规及风险评价模型为基础,对电子封装行业内通常使用的化学有害因素进行职业暴露分析,将健康风险进行分级、定量评价,得出结论:行业中回流焊工艺可能产生的铅烟、电镀车间存在的硝酸、失效分析中使用的氢氟酸等,其职业暴露风险为中等风险水平;但由于化学物质的健康危害等级HR因其固有性而相对不变,而其会随控制措施的效果高低而变化的暴露等级ER是一个可变的要素,不同企业的控制措施的水平高低不同,其最终的风险等级可能是不同的。行业中使用的氢氧化钾、氢氧化钠的职业暴露风险为低风险水平,前提也是在合理有效的控制措施环境下。因此,控制措施的水平就是决定风险等级的最重要因素。时时地运行和维护有效的控制措施,是确保风险水平不发生变化的关键。     

企业职业卫生综合风险管理评估体系的研究与应用

为了能够全面、客观地评估企业职业卫生风险管理质量,利用美国EPA吸入风险评估模型、新加坡化学物职业暴露半定量风险评估模型以及风险指数评估模型,对作业场所存在的职业病危害因素进行风险水平评估,并结合企业职业卫生管理评估模型,对企业职业卫生管理水平进行定量评估,以风险等级和管理水平,综合判断企业职业卫生风险水平。将该体系应用于实例分析,结果表明:体系在充分考虑企业职业病危害因素时空分布以及企业管理现状的基础上,能够定量评估职业病危害因素的急慢性影响以及企业职业卫生管理水平。     

大型碳化硅生产园区面源源强及减排指标核算

以某年产25万吨大型碳化硅园区无组织排放面源为例,提出基于多个地面站气象数据的CALPUFF模型地面浓度反推方法,优化流场模拟,使得无组织面源源强核算结果更加准确,并以环境保护目标空气质量达标为原则,核算其大气污染物减排指标,得出具体结论:园区大气污染物SO2、NOX、CO、PM10年排放量分别为449.06t、86.98t、5158.58t、115.06t;无组织排放SO2、CO及PM10的减排比例分别为63.5%、19.2%、42.44%,对应减排量分别为285.16 t/a、990.45 t/a、48.83 t/a。     

燃煤发电职业危害暴露健康负担评价方法*

为评估煤电行业从业人员因遭受职业危害暴露引起的健康负担大小,根据工作暴露矩阵法对燃煤发电职业暴露程度进行估算,利用健康效应分析和伤残调整寿命年指标构建燃煤发电职业暴露健康负担评价体系,实现职业暴露健康负担的量化评价。将所构建的评价体系应用于3个燃煤电厂进行对比分析,结果表明:各类危害因素中,粉尘所致健康危害最大,人均健康负担约为8.861 a;各生产环节中,运输煤系统所致健康影响最大,约占整个生产过程的45.53%。     

石材加工行业尘肺病危害风险评估研究

应用国际采矿与金属委员会风险评估模型（ICMM）评估石材加工行业尘肺病风险。 以20家石材加工企业为研究对象,运用ICMM模型的定量法和矩阵法分别评估4个重点岗位的尘肺病风险,并与粉尘作业分级和文献报道进行结果验证。 结果显示打磨、雕刻、切割和破碎4个重点岗位的总粉尘和呼吸性粉尘浓度均超过职业接触限值,超限倍数范围分别为4.3~85倍和3.1~63.3倍。ICMM定量法判定该4个重点岗位的Ⅲ期矽肺风险均为最高级风险水平（不可容忍）,矩阵法判定该4个重点岗位Ⅲ期矽肺风险也均为最高级水平（高风险）。这些风险评估结果得到生产性粉尘作业分级和文献报道的支持。结论为石材加工行业尘肺病发病风险非常高,ICMM风险评估模型可应用于石材加工行业职业健康风险评估。     

环境空气中挥发性有机物的健康风险评价研究进展

介绍了空气中挥发性有机物的研究进展,阐述了其污染对人体健康的致癌效应和非致癌效应。在此基础上对挥发性有机物的健康风险评价做了简要评述,并介绍了现在公认的健康风险评价方法,以及近年来室内外挥发性有机物污染健康风险评价的研究现状。最后,总结了健康风险评价的不足并进行了展望,提出利用不确定性方法解决健康风险评价问题将是未来研究的重点。     

工作场所超细颗粒物暴露评估与风险评估研究进展

纳米技术产业的快速发展促使纳米材料需求量不断增长,纳米材料的规模化生产及使用,增加了暴露于超细颗粒物的职业人群数量,且工种复杂多样,尤其在自动化程度低、工人职业卫生防护意识薄弱的作业场所,对接触者有潜在的职业暴露风险.从现场暴露评估策略、检测方法、接触限值以及风险评估手段,综述针对超细颗粒物这一新型职业危害因素的研究进...     

城市污水处理厂职业健康风险评估研究进展

为进一步开展城市污水处理厂职业健康风险评估工作,运用文献调研方法对国内外城市污水处理厂职业健康风险评估研究现状进行综述和展望。研究结果表明:目前,污水处理厂职业健康风险评估主要针对有毒有害气体和生物气溶胶2类危害因素;主要采用问卷调查、矩阵法和剂量-反应模型等3种评估方法;噪声和人机工程等职业危害因素的健康风险评估、暴露特征污染物的识别、复合污染物的健康风险评估、职业与非职业危害因素对工人健康影响等研究工作还有待开展。     

Noise and neurotoxic chemical exposure relationship to workplace traumatic injuries: A review

IntroductionMore than 5,000 fatalities and eight million injuries occurred in the workplace in 2007 at a cost of $6 billion and $186 billion, respectively. Neurotoxic chemicals are known to affect central nervous system functions among workers, which include balance and hearing disorders. However, it is not known if there is an association between exposure to noise and solvents and acute injuries. Method: A thorough review was conducted of the literature on the relationship between noise or solvent exposures and hearing loss with various health outcomes. Results: The search resulted in 41 studies. Health outcomes included: hearing loss, workplace injuries, absence from work due to sickness, fatalities, hospital admissions due to workplace accidents, traffic accidents, hypertension, balance, slip, trips, or falls, cognitive measures, or disability retirement. Important covariates in these studies were age of employee, type of industry or occupation, or length of employment. Discussion: Most authors that evaluated noise exposure concluded that higher exposure to noise resulted in more of the chosen health effect but the relationship is not well understood. Studies that evaluated hearing loss found that hearing loss was related to occupational injury, disability retirement, or traffic accidents. Studies that assessed both noise exposure and hearing loss as risk factors for occupational injuries reported that hearing loss was related to occupational injuries as much or more than noise exposure. Evidence suggests that solvent exposure is likely to be related to accidents or other health consequences such balance disorders. Conclusions: Many authors reported that noise exposures and hearing loss, respectively, are likely to be related to occupational accidents. Practical applications: The potential significance of the study is that findings could be used by managers to reduce injuries and the costs associated with those injures.     

职业卫生定性风险评价方法的研究

根据风险评价的原理,建立了较为完整的职业卫生定性风险评价方法,为企业进行职业卫生管理提供了充分的依据。此方法利用现场的各种信息对潜在的职业危害风险进行指数分级,在暴露评估过程中包含了危害来源,暴露途径和职业暴露的接受体这三个要素,使企业以此为依据来决定减轻职业危害的控制方法及优先顺序如化学品的替代、工程控制及个体防护用品。     

Shelter-in-place risk assessment for high-pressure natural gas wells with hydrogen sulphide and its application in emergency management

This paper provides a risk assessment method of sheltering in-place for high-pressure natural gas wells with hydrogen sulphide. In this paper, the shelter-in-place risk is estimated by integrating the health consequences of an individual taking one kind of emergency response to the emergency orders of sheltering in place from the emergency decision makers and the probability of the corresponding emergency response action. The probability of the corresponding emergency response action in the proposed method is estimated through the accident probability analysis and the probability analysis of taking a certain response action. The health consequence estimation is based on air exchange rate test of the shelter buildings as well as accident consequence calculation. The evaluation of shelter-in-place risks based on “as low as reasonably practicable (ALARP)” guidelines was employed to provide suggestions for emergency management under both normal conditions and off normal conditions. A case study of risk assessment of sheltering in the local residential houses in Xuanhan County of Sichuan Province, China was taken as an example to illustrate the proposed risk assessment process of shelter-in-place and its application in the decision-making process for emergency management.     

高科技制造业环安卫风险管理系统

只要有危害源就会存在一定的风险。由于生产过程的需要,高科技制造行业往往使用大量有毒、危险化学品,生产环境与生产设备也不同于传统产业,也因此,如何运用有效地环安卫(环境保护、工业安全、职业健康)风险管理机制来避免各种危害源可能对企业造成的负面冲击,以降低高科技行业营运过程可能遭遇的环安卫风险一直是高科技行业风险管理者所面临的挑战。本文将介绍如何以PDCA持续改善的架构来贯穿高科技行业环安卫风险管理流程与风险管理概念。     

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.     

基于危险化学品储存的区域生态环境风险评价

借鉴现有的生态风险评价方法,提出适合危险化学品储存的区域生态风险评价体系,即区域生态风险受体确定,评价终点选择,暴露途径和方式,暴露剂量分析与计算,风险表征以及区域生态风险管理对策等。研究结果表明:在有风模式中,鸟类的不可接受风险范围最远可达下风向7km,蛙类的不可接受风险最远可达下风向27km。大部分敏感点的蛙类急性暴露剂量都超标,处于不可接受风险水平;80%的敏感点的鸟类处于不可接受风险水平。根据风险评价结果,提出从防范措施、应急预案、环境监测和生态补偿4个方面制定区域生态风险管理措施。该区域生态环境风险评价研究为同类型区域生态环境风险评价提供借鉴作用。     

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.     

全球产品策略与其他化学品风险评估

为推动化学品风险评估在我国的开展,对全球产品策略(GPS)进行研究。通过对GPS实施流程的分析,确定实施GPS的核心是开展化学品的风险评估(简称GPS风险评估)。将GPS风险评估与欧盟《化学品注册、评估、授权和限制》(REACH)法规要求的化学品安全评估(简称REACH CSA)和我国新化学物质登记要求的新物质风险评估进行对比,从评估物质的要求、效应评估的范围和方法、暴露评估的范围和方法以及风险表征的方法 4个方面分析其共同点和差异。确定GPS风险评估是简化版的REACH CSA,新物质风险评估相当于REACH CSA中的环境风险评估部分。最后认为,开展化学品全面风险评估是国际化学品管理发展的趋势。针对实际情况,提出宜采取简化评估和优先评估的方法,在我国逐步开展化学品全面风险评估。