Accidents mechanical hazards

Accident Mechanism The series of events which constitute the course of events culminating in the release of hazardous chemicals outside of their nomial containment. 

For accident mechanism theory, many domestic and foreign scholars and experts have done much research and put forward a lot of typical accident theory. Such as Domino accident model theory proposed by Heinrich in 1936, Energy transfer accident theory proposed by Gibson in 1961, then derived by Haddon in 1966, Gold mine accident model proposed by Lawrence in 1974, and so on. In domestic, Chen Baozhi put forward the two class of hazard point in 1995, Zhang Li put forward Human error accident model in Complex man-machine system in 1996, He Xueqiu put forward... 

Operating Rules and Safety Mechanisms thus provide the primary protection against the most severe accidents (major hazards). 

After all of the foregoing, Heinrich set fourth, in his fourth edition, this view of the relationship that unsafe acts or exposures to mechanical hazards had to the occurrence of accidents. 

If it were practicable to carry on appropriate research, still another base therefore could be established showing that from 500 to 1,000 or more unsafe acts or exposures to mechanical hazards existed in the average case before even one of the 300 narrow escapes from injury (events-accidents) occuired. [Citation 37]... 

There is a real problem here All of those unsafe acts or exposures to mechanical hazards take place before even one accident occurs. As a concept, that is not acceptable. 

The figure shows that if you can prevent one of these conditions, then you can prevent the accident. Of course, it may not be so easy to ensure that the one that you choose actually holds up. The figure implies that the human operator committed an unsafe act (an active failure or action), which caused the accident. In reality, there were a number of other latent conditions that could have also contributed to a particular accident. These latent conditions may have existed for months or even years. When you investigate an accident, it is important to go down to the root causes, and not just the symptoms or what appears obvious, to ensure that all the accident mechanisms have been identified. Again, refer to the hazard reduction precedence in Chapter 2 on the hierarchy of hazard controls. 

In the first edition of Heinrich s Industrial Accident Prevention published in 1931, the causes of 50,000 accidents leading to injury and 500,000 accidents from which there were no injuries had been tallied with the following results human error 90 per cent, mechanical hazards 10 per cent. ( Human error included the following categories faulty instruction, inattention, unsafe practice, poor discipline, inability of employee, physical unfitness and mental unfitness.) In other words, the 90 per cent solution. 

Many workplaces have high accident incidence and severity rates because they are hazardous. Hazards are dangerous situations or conditions that can lead to accidents. The more the hazards present, the greater the chance that there will be accidents. Most hazards are from the direct release of some form of energy (i.e., mechanical, electrical, thermal, etc.). The control of hazardous energy sources is the main avenue for prevention of incidents that could result in injury, illnesses, or death. Unless safety procedures are followed, a direct relationship will exist between the number of hazards in the workplace and the number of accidents that will occur there. 

Hazardous Wastes Hazardous Wastes for deliveiy to a treatment or disposal facility normally are collected by the waste producer or a licensed, speciahzed hauler. Typically, the loading of collection vehicles is completed in one of two ways (1) wastes stored in large-capacity tanks are either drained or pumped into collection vehicles, and (2) wastes stored in sealed drums or other sealed containers are loaded by hand or by mechanical equipment onto flatbed trucks. To avoid accidents and possible loss of life, two collectors shoiild always be assigned when hazardous wastes are to be collected. 

Loss of containment due to mechanical failure or misoperation is a major cause of chemical process accidents. The design or storage systems should be based on minimizing the hkelihood of loss of containment, with the accompanying release of hazardous materials, and on limiting the amount or the release. An effective emergency response program that can reduce the impacts of a release should be available. 

Because the hazard is still present, there is always a danger that its potential impacts could be realized by some unanticipated route or mechanism. Nature may be more creative in inventing ways by which a hazardous event can occur than experts are in identifying them. Accidents can occur by mechanisms that were unanticipated or poorly understood. 

Rail accidents entailing escapes of haztu dous material happen mostly in the wake of rtiil crashes or derailments. Mechanical failures of rolling stock and faults in the rail track are frequent causes of these. Anotlier hazard of railways is fires along the track, caused bj engine or brake shoe sparks. 

Human error is frequently used to describe a cause of losses. Almost all accidents, except those caused by natural hazards, can be attributed to human error. For instance, mechanical failures could all be due to human error as a result of improper maintenance or inspection. The... 

Dow-Chemical Exposure Index (CEI)3, which are two popular forms of hazards survey. These are formal systematized approaches using a rating form, similar to an income tax form. The final rating number provides a relative ranking of the hazard. The F EI also contains a mechanism for estimating the dollar loss in the event of an accident. 

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