Hazard assessment definition

Work To Date. From 1977-80, the most intensive and productive OECD activities focused upon Mutual Acceptance of Data (MAD) and the development of test guidelines and GLP s. Efforts also were devoted to the Step Sequence Group and, in particular, that body s efforts to develop a Minimum Pre-Marketing Set of Data (MPD). Technical and scientific work also progressed on the various hazard assessment issues and expert groups worked on recommendations concerning confidential data, definitions of key terms, and principles of information exchange. 

A hazard assessment using this level of process definition rarely provides an acceptable level of safety. 

A hazard assessment based on this level of process definition should adequately protect a process when it is operating normally. It does not, however, look at the consequences of common maloperations. 

This process definition covers faults which, though not common, are known to occur in chemical processing. Examples are agitator failure, loss of plant cooling, leaks of cooling liquid into the batch, and process maloperation. Malopera-tion covers over- and under-charging of reactants, solvents or catalysts. Non-specific faults are so called because they are not specific to individual processes and the effect of them can be included in the hazard assessment without additional process description. 

For most processes a hazard assessment based on a process definition that includes non-specific faults (Section 2.4.3, page 18) is the minimum standard that leads to an acceptable level of safety. 

These regulations illustrate a trend that is occurring in safety legislation, which is now starting to move from a prescriptive approach with definitions of what has to be done in specific situations to a more risk-based approach where the precautions and actions taken are left to the individual user provided they meet certain risk-based criteria. A proposed European Directive concerning minimum requirements for improving the safety and health of workers potentially at risk from explosive atmospheres extends this concept to all work places where flammable atmospheres may be formed. When adopted, this will require all employers to carry out a hazard assessment to identify whether a flammable atmosphere is likely to exist and, where so, to demonstrate that appropriate technical, organisational and other measures appropriate to the nature of the operation have been taken to minimise the risk. 

Since the TSA conducts the security threat assessment for drivers seeking to obtain, renew, or transfer a hazardous materials endorsement (HME) on a state-issued commercial drivers license (CDL), the hazardous material definition is the same as used by PHMSA. 

Risk management estabUshes the criteria that are necessary for the identification of hazards, assessing the risk inherent within those hazards and selecting the treatments or methods for the avoidance, control, transfer, or acceptance of risk. Before managing risk, several definitions are needed. 

In order to guide the safety assessment process, it is necessary firstly to define the criteria used to judge the acceptability of hazards. These definitions are fundamental to understanding the data presented, as the resultant safety acceptance criteria form the baseline standards against which the system is then evaluated in the final system safety assessment (SSA) report. For more information, see Chapter 5 and Appendix B. 

The SFA requires the definition of respective substances, a comprehensive analysis of the system (i.e. boundaries), and it is always limited in its extent due to process properties and data availability. Within this chapter the implementation of SFA for tracing hazardous substances in international informal e-waste treatment has been proved to be a useful method. To assess the hazardous consequences and potential risks of the selected chemicals to humans and the environment caused by informal recycling activities in those regions, different models exist, from which four have been chosen according to their specific focus and various pros and cons. 

In summary, it is reasonable to conclude that bioinformatic analysis of structural similarities to, or of sequence homology with, known protein allergens, and evaluation of stability with SGF, can both contribute, if interpreted cautiously, to an overall assessment of sensitizing hazard. However, these analyses, neither alone nor in combination, provide a definitive answer regarding allergenic potential, and for this reason there has been interest in exploring a more holistic approach (and more definitive assessment) that may be provided by suitable animal models. 

Hazard is commonly defined as the potential to cause harm . A hazard can be defined as aproperty or situation that in particular circumstances could lead to harm (Smith et al., 1988). Risk is a more difficult concept to define. The term risk is used in everyday language to mean chance of disaster . When used in the process of risk assessment it has specific definitions, the most commonly accepted being The combination of the probability, or frequency, of occurrence of a defined hazard and the magnitude of the consequences of the occurrence (Smith et al., 1988). 

The correlation (or lack of correlation) of other physiochemical characteristics has not yet been established. For instance, are all surfactants irritants Can one classify severity by the size of the molecule Can octanol water partition coefficients predict irritation potential does a propensity to partition out of the ocular fluid mean that a compound presents more of an irritation hazard than one which is more water soluble Theoretically, these data should reflect the ability of a compound to penetrate the eye and cause an irreversible lesion. However, until definitive data are available, physical and chemical parameters will probably have limited utility in an overall assessment of irritation. 

Procedural controls, process controls, 98-99 Process controls, 96-100 active controls, 98 inherently safer approach, 97 mitigation techniques, 99 passive controls, 97-98 procedural controls, 98-99 safe operating limits, 99-100 Process definition, documentation, 102-104 Process design, documentation, 105 Process hazard analysis (PHA) risk assessment, 92-93 screening methods, 63 Process risk management decisions, documentation, 105-106... 

Fault tree analysis is based on a graphical, logical description of the failure mechanisms of a system. Before construction of a fault tree can begin, a specific definition of the top event is required for example the release of propylene from a refrigeration system. A detailed understanding of the operation of the system, its component parts, and the role of operators and possible human errors is required. Refer to Guidelines for Hazard Evaluation (CCPS, 1992) and Guidelines for Chemical Process Quantitative Risk Assessment (CCPS, 2000). 

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