Hazards, plant

Smoking stations (in hazardous plants) Product loading stations... 

Tyler, B. J. (1985). Using the Mond Index to Measure Inherent Hazards." Plant/Op-erations Progress 4, 3 (July), 172-75. 

This is particularly relevant in situations where a human intervention is required in response to a potentially hazardous plant situation. 

The project began with an extensive evaluation of 900 reported incidents involving failures of fixed pipework on chemical and major hazard plant. As part of the analysis a failure classification scheme was developed which considered the chief causes of failures, the possible prevention or recovery mechanism that could have prevented the failure and the underlying cause. The classification scheme is summarized in Figure 2.13. A typical event classification would be... 

It is important that the designer/project engineer become familiar with all process-related features of the full code and to recognize and identify the requirements for hazardous plant-related situations ... 

Mancini, R.A., The use (and misuse) of bonding for control of static ignition hazards, Plant/Operations Progress, 7, No. 1, January 1988. 

The Bhopal plant of Union Carbide was built originally 1.5 miles from the nearest housing (see below under Case Histories ). Over time, a residential area grew up next to the plant. This demonstrates the need to prevent hazardous plants from being located close to residential areas and to prevent residential areas from being established near such plants.4 If possible, the cost of a plant should include an adequate buffer zone unless other... 

Zoning regulation is certainly one of the oldest and most obvious forms of risk reduction. By splitting the territory and isolating hazardous plants, public exposure to risk is diminished. One of the main problems at Seveso was that several municipalities extended up to the plant s boundary. 

Seismic action can cause serious accidents to industrial plants as shown in several occasions. The actual worldwide situation of major-hazard plants against earthquakes should be considered as critical. For instance, in Italy about 30% of industrial plants with major-accident hazards are located in areas with a high seismic risk. In addition, in case of a seismic event, the earthquake can induce the simultaneous damage of different apparatus, whose effects can be amplified because of the failure of safety systems or the simultaneous generation of multiple accidental chains. 

Fimctional safety is a part of general safety, which depends on the proper response of the control and/or protection systems to the inpnt signals during abnormal states of a machine, installation or hazardous plant. The concept of functional safety formulated in lEC 61508 presents an example of good engineering practice applied to the design and operation of the safety-related electric, electronic and programmable electronic (E/E/PE) systems. The term safety-related applies to the systems that perform specified fiinction(s) to ensure that the risk is maintained at acceptable level. Two different requirements should be satisfied to ensure the functional safety ... 

Human operators who control and supervise the production process in hazardous plants make decisions based on the signals and indications presented on interfaces that should be carefully designed especially for potential abnormal situations and critical events. The research findings concerning the industrial accidents indicate that 70-90% of accidents were caused due to human errors and related failures influenced... 

Proper designing of the alarm system, as the layer of protection in hazardous plant, will contribute to reducing the hmnan error probability (HEP), what will result in decreasing the risk of potential accidents. The human and organizational factors should be also care fully considered in designing and operating of protections to eliminate or reduce probability of latent and active failures (Kosmowski 2007). 

In modem hazardous plants several layers of protection can be distinguished (Fig. 1), e.g. Basic Process... 

Figure 1. Some layers of protection in a hazardous plant.

With regard to normal and abnormal states of hazardous plant several monitoring and control loops may be distinguished as illustrated in Fig. 3. In normal plant states and some disturbances the operator is supervising the technological process because the control is performed automatically. In case of malfunctions and abnormal states the operator should be informed about current situation by the alarm system. The role of operator in hazardous state of the plant (dashed line), in order to prevent a serious accident, can be decomposed into several general task illustrated on Fig. 4 (Hollnagel 2005). 

It is required to manage the functional safety in entire safety lifecycle keeping the risk level of potential hazardous events at acceptable level. Thus, it is essential to modernize and improve when required the basic process control system (SCADA and DCS) and the safety-related systems including the alarm system based on experience from their operation and periodical risk assessment. In such process it is essential to consider carefully the human and organizational factors using relevant HRA methods to maintain adequate risk associated with operation of complex industrial hazardous plants. 

The thrust of chemical process safety can be thought of as an extension of system safety as applied to the chemical process industry. But also important is that the safety risk-basis of the approach to achieve a less hazardous plant environment is applicable beyond chemical matters and into the facilities and operations of most industrial activities. 

Poison oak — Another hazardous plant with three leaves is poison oak. It is a woody plant that grows in diy, barren areas ranging from southern New Jersey to northern Florida, and as far west as Oklahoma. In the East it grows as a shrub. In the West it may grow as a vine as well as a shrub. 

Since the only mention OSHA makes on poisonous plants is formd in the safety training and education section, employees must be trained in whatever possible hazards they may be exposed to, including hazardous plants. 

Many small simple relatively low hazard plants are fully manually operated, but with increasingly complex plant and especially where increasing hazards, risk, criticality and quality needs are met there is a tendency to introduce automated controls using electronic control systems °. However, because a plant is computer-controlled does not necessarily make... 

This verification is referred to as an operability study [4-20), [4-21], technical safety discussion [4-22J, or PI flow chart review [4-23] and is implemented according to different principles. H. Lawley [4-20] has established a strict system for the procedure. For the detection of the safety-relevant components, he follows the PI flow chart, and for the detection of hazardous plant conditions, a list of code words. H. Ullrich [4-24] describes a different way of proceeding. He applies a series of checklists in a determined sequence to the planning documents to confirm complete technical safety provisions. Individually such checklists are used to examine the completeness of procedure planning and construction documents as well as measuring and control plans. 

Health and safety policies may outline objectives in key health and safety areas, such as mobile equipment hazards, plant or noise. They may outline the key occupational health and safety accountabilities of the different levels of staff. 

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