Secondary hazards, electricity

Electrical hazards are frequently encountered in the laboratory, where there are many kinds of apparatus, equipment, and instruments that utilize electricity. The primary hazards of direct exposure to electricity are electrocution, electrical shocks, burns, or falls that are secondary to electrical shocks. Incident 5.3.5.1 illustrates the very real possibility of electrical shock from exposures in the laboratory. Although rare, there have been fatalities in the laboratory from unsafe practices with electrical apparatus and equipment. 

Secondary hazards are those additional hazards which present themselves as a result of an electrical hazard. It Is very Important that these hazards are considered during a risk assessment. An electric shock could lead to a fall from height If the shock occurred on a scaffold or it could lead to a collision with a vehicle if the victim collapsed on to a roadway. 

Isolation of electrical supplies throughout a building (service risers) can be achieved by ensuring that the risers are fire resistant enclosures, thus should a fire start the secondary hazard (such as the production of smoke) is contained within the enclosure and will not have an adverse effect upon those escaping. 

Approved Independent Backup (AIB) - A secondary non-electrical/instrument safety layer, such as a relief valve used to prevent over pressure in a vessel. This feature will protect against a hazard If the Basic Process Control System fails. An event classification based on the existence of an Approved Independent Backup assumes that the process will be operational only when the Approved independent Backup features are operational. The backup should have the following features ... 

In high-voltage applications (e.g. off-line power supplies), it may in fact be required by law, to provide electrical isolation between a hazardous input voltage level and user-accessible ( safe ) output terminals of the power supply. Therefore there is a primary ground at the input side of the transformer, and a separate secondary ground on the output side. 

When arriving on scene the number of potential victims should be acquired. Certain hazards to look for in a structural collapse are a secondary collapse, live electrical wires, and gas leaks. The electricity and gas should be shut-off. Structural collapses come in three different types pancake collapse, lean-to collapse, and v-type collapse. 

The environmental aspects of coal combustion have been a major factor in the various processes, and the movement of the fossil fuel base away from petroleum and natural gas to coal has increased the need for effluent/pollutant control for large, fossil-fueled power plants (Argonne, 1990). Very large amounts of coal are consumed in generating electricity and the emissions from power stations and similar industrial sources represent a potential, and considerable, environmental hazard. These power plants and the accompanying flue gas desulfurization processes emit effluents, which often are pollutants, and which by mere contact with the external environment or by (generally) simple atmospheric chemical transformations, may form secondary pollutants that are more harmful than the initial effluent/pollutant. 

At construction sites the most common electrical hazard is the grovmd fault electrical shock. A ground fault occurs when a hot electrical wire contacts a grounded enclosvu-e. In most situations, the fault will trip a circuit breaker or blow a fuse. However, if a break in the ground wire occurs, the worker would no longer be protected, unless a secondary safety measure is available. 

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