Hazard probability defined

The combination of the hazard severity and the hazard probability defines the hazard risk classes. These classes are listed in Table 4 with different levels of tolerability Class A forms the intolerable area of the risk matrix, Class B and C the tolerable area and class D means acceptable risk. 

Introduction The meaning o hazard is often confused with risk. Hazard is defined as the inherent potential of a material or activity to harm people, property, or the environment. Hazard does not have a probability component. 

Hazard, risk, failure, and reliability are interrelated concepts concerned witli uncertain events and tlierefore amenable to quantitative measurement via probability. "Hazard" is defined as a potentially dangerous event. For example, tlie release of toxic fumes, a power outage, or pump failure. Actualization of the potential danger represented by a hazard results in undesirable consequences associated with risk. 

Before continuing, it is necessary to distinguish between the concepts of hazard and risk because they are often used interchangeably which is inappropriate and potentially confusing. Hazard is defined as an inherent capacity of an agent to result in harm, whereas risk is defined as the probability that harm may result under the appropriate set of circumstances. This relationship can be expressed with the following formula ... 

Where the need for fire detection is identified, the required performance of the fire detection system is already specified as part of the grading process. Fixed fire detection is typically installed to protect equipment that is high value, long lead time, or likely to be significant fire escalation hazards. The performance specification defines fire size and response time thresholds for alarm and action(s). Fire hazards are defined by radiant heat output (RHO). RHO gives a reasonable indication of the potential damage and the probability that the fire will escalate or cause loss. The RHO should not be used to determine fire thermal loading onto equipment and structures. Table 8-3 compares RHO and flame area for some typical hydrocarbon fires. 

Hazard probability is defined as the aggregate of the likelihood that the potentials of hazards will be realized and that a hazards-related incident will occur. Hazard probability is to be described in probable occurrences per unit of time, events, population, items, or activity. 

Risk Mathematically, expected loss the probability of an accident multiplied by the quantified consequence of the accident (SSDC) an expression of the possibility of a mishap in terms of hazard severity and hazard probability (MIL-STD-882) note Hazard exposure is sometimes included (AFR 800-16) as defined in NHB 5300.4(10-2), The chance (qualitative) of loss of personnel capability, loss of system, or damage to or loss of equipment or property (NSTS 22254) a measure of both the probability and the consequence of all hazards of an activity or condition. A subjective evaluation of relative failure potential. In insurance, a person or thing insured (ASSE). 

The next step requires a probability assessment be conducted for the hazard. The probability that an injury or illness will result from a hazard has no role in determining the classification of a violation, but does affect the amount of the penalty. The probability is categorized either as greater or as lesser probability, defined as follows ... 

Estimations of probability defined with help of cumulative distribution function can be applied for investigation within some area where maximum a and minimum b values of analyzed factor are established. In this case as hazardous parameter assess an interval probability Pab of karst forms development. Accuracy of estimation with using interval probability Pab depends on the sizes of study area and homogeneity of natural conditions within its borders. Let s notice, such approach to assessment of probability is widely applies in reliability theory of systems. 

Risk is expressed as an estimate of the probability of a hazard-related incident or exposure occurring and the severity of harm or damage that could result. All risks with which safety and health professionals deal derive from hazards. There are no exceptions. A hazard is defined as the potential for harm. Hazards include all aspects of technology and activity that produce risk. Hazards include the characteristics of things (equipment, dusts, chemicals, etc.) and the actions or inactions of people. 

Or we could further define risk as the triplet event scenario, probability of occurrence, and consequence. Event scenario is a description of the event under study. In safety parlance, what are the hazards Probability of occurrence is our quantification of the likelihood that the event will occur. Consequence is defined as the severity of the event. 

The hazards and risks associated with work activities need to be identified first. Hazards are defined as situations with the potential to cause harm or loss. Under the CDM Regulations it is both hazardous circumstances and hazardous activities that potentially threaten the health and safety of employees. So the identification of hazards and activities is an essential part of analysing the risks that these represent to health and safety in the workplace. Risk is a function of three factors the likelihood of actual harm resulting from a hazard, the potential severity of the consequence should it occur, and the number of people that might be exposed to the harm. There are a number of well established methods by which risks may be quantified and hazard indices developed, if reliable data is available. Risk is normally measured in terms of the probability of a worker being injured in any given year, while carrying out his or her work, by the severity of injury suffered. Accident frequency is often used as the prime indicator of risk overall. 

Previous issues of MIL-STD-882 used the term hazard (defined as a condition that is a prerequisite to a mishap , and went on to define hazard severity and hazard probability levels (see Tables B.13 and B.14). This was definitively incorrect, as these categories described accidents (or mishaps) - not hazards. 

Likelihood Likelihood defines in quantitative or qualitative terms, the estimated probability of the specific hazardous event under study. Likelihood is one element of associated risk (the other being severity). Fault trees and other models can be constructed and individual hazard probabilities are estimated, and likelihood can be calculated via Boolean Logic. 

Risk is defined as an expression of possible loss over a specific period of time or number of operational cycles. It may be expressed as the product of hazard severity and hazard probability. 

Since 1970 tlie field of healtli risk assessment Itas received widespread attention witliin both tlie scientific and regulatoiy committees. It has also attracted tlie attention of the public. Properly conducted risk assessments have received fairly broad acceptance, in part because they put into perspective the terms to. ic, Itazard, and risk. Toxicity is an inlierent property of all substances. It states tliat all chemical and physical agents can produce adverse healtli effects at some dose or under specific exposure conditions. In contrast, exposure to a chemical tliat lias tlie capacity to produce a particular type of adverse effect, represents a health hazard. Risk, however, is tlie probability or likelihood tliat an adverse outcome will occur in a person or a group tliat is exposed to a particular concentration or dose of the hazardous agent. Tlierefore, risk can be generally a function of exposure and dose. Consequently, healtli risk assessment is defined as tlie process or procedure used to estimate tlie likelihood that... 

The risk evaluation process defines the equipment, hazards, and events leading to an accident. It detennines the probability tliat an accident will occur. The severity and acceptability of the risk are also evaluated. 

This is defined as the relative concentration of sodium to calcium plus magnesium, and is represented by a parameter known as the sodium adsorption ratio (SAR). The absolute concentration values of the different cations in irrigation water are not adequate for estimating probable hazards. An important consideration is the extent to which the exchangeable sodium percentage (ESP) of the soil will increase as a result of adsorption of sodium from the irrigation water. The higher the ratio, the... 

A hazard can be defined as a situation which may lead to harm, whilst risk is the probability that harm will occur. From the point of view of harm being caused by exposure to a chemical. Equation 1.3 is applicable. 

When chemicals are released in the environment, their hazard potential to human or ecological receptors depends upon the extent of contact between the receptors and the chemical. This exposure level is not only influenced by where, when and how much of the chemical is released, but also on its movement and changes in air, water, soil or biota relative to the locations of the receptors. Risk is defined as the probability of some adverse consequence in the health context, or as the probability times the extent of the consequence in the technology context. In this paper we shall examine and discuss how mathematical models are used to generate estimates of risk when more than one of the environmental media must be considered in tracing pathways connecting sources with receptors. The principal objective here is to place in perspective the... 

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). 

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