System Hazards

Characterizing chemicai reactivity hazards invoives a review of the inherent thermai hazards of the pure process materiais as weii as the thermai hazards of the materiais under processing conditions. Gaining this understanding and characterizing thermaiiy hazardous systems is a muitistep process. 

Information on the types of human interactions with hazardous systems that occur would be obtained from sources such as plant operating instructions, job safety analyses and similar sources. These interactions are referred to as critical tasks (CT). 

Given that workers interact with hazardous systems, how frequently are they likely to make errors in these critical tasks ... 

However, it emerged dining the compilation phase that most two component reaction hazard systems of this type involve a fairly obvious oxidant material as one of the reactants. Where this situation was recognised, the oxidant has normally been selected as primary (indexing) reactant, with the other as secondary reactant, following the colon. 

Such thermal run-away reactions are referred to as thermal explosions . These thermal explosion reaction types convert potential hazardous systems into real hazardous systems. Thus, it is necessary to answer both of these two main questions to evaluate the real hazard of a system ... 

Explosion suppression is used for the protection of extremely hazardous systems in industry. Explosions that develop very high radial flame speeds (such as hydrogen-oxygen) are too fast for existing equipment. Many detonations (ultrasonic) also develop from an initial deflagration. It is possible... 

One of the most promising technical approaches to regulation of hazardous wastes (and one that already seems in progress for evaluation and response to old problem sites) is the development of a degree of hazard system of waste classification. The current RCRA approach and, to a slightly lesser degree, the Louisiana approach tend to treat all hazardous wastes as about equal. In fact, however, it is apparent that waste materials differ very greatly over a spectrum of intensity of the characteristics that make them hazardous. This is particularly so for the characteristic of toxicity. 

Limited identification of hazards System performance may be worse System is harder to maintain The prototyping approach requires more experienced team members... 

Postulate 2. The degree of completeness of the set of internal restraints and exogenous factors specifying a hazardous system and its transformation, determines the degree of completeness with which the pathways leading to a hazardous state can be identified. 

Safe handling with secure systems to ensure safe and easy sampling from hazardous systems. 

Accidents hke the Mars Polar Lander or the British batch chemical reactor losses, where the cause lies in dysfunctional interactions of non-failing, reliable components—i.e., the problem is in the overaU system design—illustrate reliable components in an unsafe system. There can also be safe systems with unreliable components if the system is designed and operated so that component failures do not create hazardous system states. Design techniques to prevent accidents are described in chapter 16 of Safeware. One obvious example is systems that are fail-safe, that is, they are designed to fail into a safe state. 

Some of the most important assumptions in safety lie in our models of how the world works. Models are important because they provide a means for understanding phenomena like accidents or potentially hazardous system behavior and for recording that understanding in a way that can be communicated to others. 

Losses result from component failures, disturbances external to the system, interactions among system components, and behavior of individual system components that lead to hazardous system states. Examples of hazards include the release of toxic chemicals from an oil refinery, a patient receiving a lethal dose of medicine, two aircraft violating minimum separation requirements, and commuter train doors opening between stations. ... 

The hazards, system safety requirements and constraints, and documentation of the safety control structure for pharmaceutical safety were shown in chapter 7 Using these, Couturier performed several types of analysis. 

C.2 System Hazards, System Safety Constraints, and Control Structure... 

ID Component in zone External failure mode(s) Intrinsic hazards Systemic vulnerabilities Effect on the aircraft Corrective/preventative action and/or mitigations... 

Protection - National Research Institute (CIOP-PIB) for co-operation in preparing a research programme concerning the safety management of hazardous systems including functional safety aspects. 

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