Safety concepts

The safety philosophy is based on dividing the site installation into two distribution systems the 400/230 V system where there is a comparatively high shock risk because the voltage to earth is 230 V, and the comparatively safe 110 V system where the voltage to earth does not exceed 64 V. The 400/ 230 V system is intended to be installed and maintained only by authorised and competent persons, i.e. those who are electrically qualified. The construction workers role is confined to operating the distribution equipment, which is metalclad, weatherproof and earthed. The portable apparatus which they constantly handle is all connected to the llOV system (see Fig. 11.1). 

BS 4363 Distribution units for electricity supplies for construction and building sites, was issued in 1968, and was amended in 1992 for compatibility with BS EN 60439-4 1994. This standard specifies the equipment. In 1969 BS CP 1017 appeared. This was the code of practice which describes how the BS 4363 apparatus was to be installed and used. This code was subsequently amended and renumbered as BS 7375 1996. See also HSE guidance booklet HS(G)141 - Electric Safety on Construction Sites. 

The distribution equipment comprises a number of metalclad, fireproof and weatherproof units with airbreak switches and circuit breakers. Although not a requirement in the standard, the transformers used in practice are generally of air-insulated or resin-encapsulated construction. The apparatus is robust to withstand rough handling, free-standing and 

To cater for the supply company s needs, the standard describes the requirements for an incoming supply assembly (ISA). It has two compartments with lockable access - one for the incoming cable termination, service fuses, neutral link, current transformers and meters, and another for the consumer s main switchfuse or circuit breaker fitted with excess current protection and, where appropriate, earth leakage protection. 

The main switchboard is called a Main Distribution Assembly (MDA) and consists of an on load isolating switch which feeds a set of busbars to which are connected a number of moulded case circuit breakers (MCCBs) (see Fig. 11.2). For smaller sites and/or where it may be convenient, the ISA and MDA can he joined to form a combined incoming supply and main distribution assembly (ISDA). In this case the on load isolator is omitted. 

According to [16] risk must be assessed in order to develop a safety concept for the system to be protected. In the informative part of [16] an assessment is carried out for an in-line detonation arrester, which is based on a qualitative estimate of risk. In doing this the following factors must be accounted for  

The assessment may suggest the conclusion that more than one protective measure must be installed in order to sufficiently reduce the probability of flame propagation. A relevant safety concept may consist, for example, of an inline detonation arrester, which is located as closely as possible to the installation to be protected, and (as an additional measure) an inline deflagration arrester close to the potential source of ignition. 

This principle is demonstrated in Table 7.4. In that table the probability of ignition is combined with the probability of the existence of a flammable mixture. 

The required number of independent measures leads to the same safety level. One of the measures of Table 7.4 is an in-line detonation arrester. 

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Therefore we as an independent service organisation for the industry have had to develop a new safety concept, which... 

NFPA 550 Guide to the Fire Safety Concepts Tree. National Fire Protection Association, Quincy, MA. 

This guideline describes methods to help the chemical processing industry apply the CCPS chemical process safety concepts to outsourced manufacturing operations, specifically the tolling vendor-client relationship. In addition to the focus on process safety, information and examples provided in this text foster good practices relative to community and worker health, and environmental responsibility. 

Haag, G., Kugeler, K. and Philippen, P.-W., The high temperature reactor (HTR) and the new German safety concept for future nuclear power plants. In Proceedings of the... 

During process hazards reviews (such as HAZOP), inherent safety concepts are also considered. Mistake proofing the design should receive attention and each safety critical device (last line of defense) and safety critical procedure should be examined to see if there is a way to eliminate the need for the device or procedure. 

Companies may wish to develop workshops to train potential team members in the inherent safety review process. The workshop can provide background information on inherent safety concepts, the extensive systems required to manage hazardous materials, and information on the inherent safety review process. Videos, problems, examples, and team exercises can be included to enliven the education process. 

Dobbs et al, Approved Safety Concepts for Use in Modernization of USAMUCOM Installations , PATR 4429 (1972) 12) J.A. Ruth... 

The worst hazard scenarios (excessive temperature and pressure rise accompanied by emission of toxic substances) must be worked out based upon calorimetric measurements (e.g. means to reduce hazards by using the inherent safety concept or Differential Scanning Calorimetry, DSC) and protection measures must be considered. If handling hazardous materials is considered too risky, procedures for generation of the hazardous reactants in situ in the reactor might be developed. Micro-reactor technology could also be an option. Completeness of the data on flammability, explosivity, (auto)ignition, static electricity, safe levels of exposure, environmental protection, transportation, etc. must be checked. Incompatibility of materials to be treated in a plant must be determined. 

Elimination or minimization of all causes of accidents by applying the inherent safety concept. 

Inherent safety concept. This route requires the deepest understanding of the chemical process, and, accordingly, of the potential hazards. It is not easy, even at a high degree of understanding, to eliminate mistakes in assessment. However, this approach is strongly supported by many specialists in problems of safety in the chemical industry. According to Kletz(1983) ... 

Management systems for chemical process safety are comprehensive sets of policies, procedures, and practices designed to ensure that barriers to major incidents are in place, in use, and effective. The management systems serve to integrate process safety concepts into ongoing activities of everyone involved in operations— from the chemical process operator to the chief executive officer. 

This article shows, through example, how established system safety concepts can be used to develop safety criteria for the design of a chemical surety materiel laboratory. This systematic approach, when applied as described in this article, results in a laboratory dedicated to achieve mission objectives in an environment relatively free of inherent hazards for the least number of dollars. 

Facility System Safety (FSS), which is the application of system safety concepts to the facility acquisition process, has recently gained acceptance throughout the Department of Defense and most recently within the Department of Army with the conception of SAFEARMY 1990. The Army s goal is to fully integrate the total system safety, human factors, and health hazard assessments into continuous comprehensive evaluation of selected systems and facilities. The Chemical Research Development and Engineering Center (CRDEC) has mandated appropriate levels of system safety throughout the lifecycle of facility development for many reasons. These include ... 

One of the serious problems which has faced both manufacturers and users in applying the intrinsic safety concept has been the inability to interconnect apparatus of different manufacturers and... 

This Chapter starts with an example of an actual accident, that occurred in spite of all the measures and indicators implemented to prevent it from happening. Subsequently, some important safety concepts are defined to prevent confusion and misinterpretations. Then it is discussed why in spite of the developments in safety scope and environment since the industrial revolution measuring safety is still a problem. The Chapter ends by presenting the research scope and the derived research questions. 

The topics for this checklist have been taken from CCPS (1993b) and Bollinger et al. (1996). Every effort was made to ensure that this checklist is comprehensive therefore, there may be some redundancy or overlap in questions among the different sections. It should be noted that some of the items in this checklist employ a very broad concept of inherent safety, as presented by Bollinger et al. (1996). As such, they may address inherent aspects of passive, engineered or even administrative controls, rather than the narrower inherent safety conception of reducing the underlying process hazards that must be contained and controlled to safely operate a facility. 

The methodology outlined in this chapter follows that in Cuidelines for Chemical Process Quantitative Risk Analysis (CCPS, 2000). NFPA 550 Cu/de to the Fire Safety Concept Tree provides another example of fire risk assessment. There are three keys to a successful fire risk assessment ... 

One of the most critical steps in establishing the appropriate role and settings of the individual safety systems will be the risk assessment analysis, the process in which engineers consider and analyse all possible conditions in order to select the most appropriate safety concept, which ensures safe operation under all possible circumstances and scenarios (see Section 13.4). 

Tadiran Li/Mn02 (3.0 V), a return to rechargeable Li metal utilizing novel chemical safety concepts. Widespread acceptance has been hampered by memories of earlier rechargeable Li metal systems limitations. 

Some time back, the Ammunition Equipment Office was tasked to develop a safe and ecologically clean demilitarization system for unserviceable nerve gas filled chemical munitions. Following the time-proven safety concept of having the least quantity of explosive filled munitions and the least number of operators present at the operation for the shortest possible time. Ammunition Equipment Office designed and developed the system shown at Figure 3. The machine developed to demilitarize the munitions is housed in a very substantial explosive containment vessel. 

Uchegbu, L Florence, A. Adverse drug events related to dosage forms and delivery systems. Drug Safety Concepts 1996, 14 (1), 39-67. 

In this article, we will go through the safety concepts that can be applied to a chemical substance to give the readers a general overview of the matter. The safety of hazardous pharmaceuticals is a field that can be included in this approach, and many suggestions or proposals regarding pure chemicals will be discussed. The term chemicals is used interchangeably with pharmaceuticals because all pharmaceuticals are, in essence, chemicals. 

It would not be proper to talk about servicing anything without introducing at least basic safety concepts. This chapter included a discussion of the safety precautions that must be taken when servicing computers, as well as the proper way of executing them to ensure that technicians don t inflict damage to either themselves or the computer. 

In application of inherent safety concepts, I2SI indexing system is used for quantification of process units and equipment response. 

Contaminated feed poses a serious source of infection for livestock. Animals rarely show symptoms of salmonellosis and there is always the risk of undetected carriers entering the food production chain. Safe feed is the first step in a farm-to-fork food safety concept to guarantee safe food. All raw feed components should be considered as a potential source of Salmonella, and, therefore, decontamination steps are of utmost importance to avoid contaminated feed spreading to herds (Sauli, Danuser, and Geeraerd, 2005). 

Safety using nitric acid at high temperatures and pressures requires a well-conceived and continually executed safety concept, using advanced reaction technology. 

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