Severity categories hazard

Table IV. Hazard Severity Categories Defined in MIL-STD-882A...

Table 14.2. Hazard severity categories, adapted from MIL-STD-882D and Sverdrup Technology Publications...

MIL-STD-882 establishes system safety criteria guidelines to assist in the determination of hazard severity. The hazard severity categories listed in Table 2.1 provide... 

Risk Assessment Matrix Ij HAZARD SEVERITY CATEGORIES ) ... 

First, assign hazard severity categories to each hazard. 

A CSI is essentially the same as an SCI except that systems required to identify CSIs have additional statutory and regulatory requirements that the contractor must meet in supplying those CSIs to the government. For systems required to have a CSI list, HA and mishap risk assessment is used to develop that list. The determining factor in CSIs is the consequence of failure, not the probability that the failure or consequence would occur. CSIs include items determined to be life-limited, fracture critical, fatigue-sensitive, and so on. Unsafe conditions relate to hazard severity categories I and II of MIL-STD-882. A CSI is also identified as a part, subassembly, assembly, subsystem, installation equipment, or support equipment for a system that contains a characteristic, failure mode, malfunction, or absence of which could result in a Class A or Class B accident as defined by DoDINST 6055.7. 

HA is qualitatively performed in both narrative and matrix formats. The common matrix used across most disciplines nses Categories of Severity and Levels of Probability. Hazard Severity Categories from I to TV provide a measure of the worst credible mishap resulting from personnel error, environmental conditions, design... 

Ref. 39 suggests an initial qualitative hazards analysis early in systems design, with only general levels of hazard probabilities identified, in addition to severity categories. An example of such a qualitative ranking from Ref. 39 appears in Table V. 

The characteristics of a chemical or substance that would categorize it as a reactive material include (1) it reacts violently with water, (2) it forms potentially explosive mixtures with water, or (3) when mixed widi water or other chemicals, it generates toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health or the environment. Because water is the most common fire suppressant, the characteristic of reactivity is especially relevant since the application of water to eliminate or prevent the spread fires may be counterpro-ductive rather than helpful. Several categories of chemicals will be discussed from this standpoint however, several of these same chemicals also present additional hazards. 

LDRs specified in RCRA required EPA to develop treatment standards for hazardous chemical waste and established deadlines for EPA to develop treatment standards for those wastes for which treatment standards did not exist. Congress divided LDR hazardous waste into several categories solvents and dioxins California listed wastes first, second, and third listed wastes and characteristically hazardous wastes. 

Hazard category means the division of criteria within each hazard class, e.g. oral acute toxicity includes five hazard categories and flammable liquids includes four hazard categories. These categories compare hazard severity within a hazard class and should not be taken as a comparison of hazard categories more generally ... 

The results of these studies are compared initially to finite regulatory criteria which place the pesticide into one of several categories. In the most usual case the criteria of risk potential are not exceeded and the mere fact that the pesticide performs its intended function is adequate to determine that benefits exceed risks. Such products are registered with little if any sophisticated assessments of actual hazard, exposure or economic benefit. 

To rationalise this dilemma, it is necessary to consider the typical or most frequent outcome and assess the severity of that event. In other words, this is an educated judgement call based on previous experience in the clinical domain. In this case one would need to consider, across all specialties, appoinunents types, consultants, medical conditions and patients, what is the typical and most appropriate severity category associated with an appointment not being scheduled Whilst this might not stand up to the detailed scrutiny of the scientific method, remember that what is important is the relative magnimde of the severity compared with other hazards under consideration. 

Many of the incidents occurred due to a combination of causes and validly could be assigned to several categories, but for simplicity they have been assigned here to one category only — the prime (or prima facie) cause. As will be appreciated, the prime cause is often merely the symptom of a more deep-rooted cause — for example, lack of a systematic approach to reaction hazards assessment, no proper basis of safety, inadequate attention to plant design and control, and poor or absent operating procedures, instructions and training. 

Even though some NASA documents reference the use of risk assessment codes (RACs), risk assessment for many NASA efforts is based on hazard level or criticality category. If risk assessment codes are used, they tend to use the hazard severity and probability categories and matrices from MIL-STD-882B. The NASA hazard levels are... 

Table 2.3 shows the hazard risk matrix, which incorporates the elements of the hazard severity table and the hazard probability table to provide an effective tool for approximating acceptable and unacceptable levels or degrees of risk. By establishing an alphanumeric weighting system for risk occurrence in each severity category and level of probability, one can further classify and assess risk by degree of acceptance. Obviously, from a systems standpoint, use of such a matrix facilitates the risk assessment process. 

To minimize the danger to life and property, controls for hazards fall into several categories. Controls include defining and recognizing hazardous materials, excluding certain... 

Therefore, when using the severity and probability techniques simultaneously, hazards can be examined, qualified, addressed, and resolved based upon the hazardous severity of a potential outcome and the likelihood that such an outcome will occur. For example, while an aircraft collision in midair would unarguably be classified as a Category I mishap (catastrophic), the hazard probability would fall into the Level D (remote) classification based upon statistical history of midair collision occurrence. The system safety effort in this case would require specific, but relatively minimal... 

---