OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 36 Mining

Section 692 Self rescuer

A self rescuer is a type of respiratory protective equipment that underground miners can put on quickly if the atmosphere becomes hazardous due to noxious gas concentrations or smoke. Self rescuers are intended to give workers enough time to safely reach a refuge station or the surface, depending on how far away the worker is from either of these locations. Everyone who enters an underground mine must carry a self rescuer and be trained to use it properly.

This section requires the use of self-contained self rescuer devices. Such devices are self-contained because they generate oxygen and are also known as oxygen-generating self rescuer devices. International experience in recent years has shown that carbon monoxide filter-type devices alone can be insufficient as workers have perished from oxygen deficiency. Industry has therefore adopted the more effective self-contained self rescuer device because it generates oxygen to breathe and excludes any airborne contaminants. Such devices are now widely available and typically have a one-hour rating. This means that they provide a worker with oxygen for up to 60 minutes depending on the worker’s physical condition, fitness and activity level.

Subsection 692(a)

Self rescuers are intended to give workers breathable air for long enough to safely reach a refuge station or fresh air, depending on how far away the worker is from either of these locations. Self rescuers must be available for all persons underground.

Two types of self rescuers are commonly used in underground mines. The first is the filter type which is equipped with a  filter that protects the wearer from as much as one percent carbon monoxide (CO) for one hour. In the presence of a high concentration of CO, the filter self rescuer can become very hot. The filter type is designed only to deal with CO, a product of combustion and lethal at very small concentrations. Thus the worker is breathing in mine air but with the CO filtered out. If the oxygen content of the air is low, this type of self rescuer cannot help and the worker is still at risk.

The second type, the oxygen generating self-rescue device, generates a supply of oxygen for the worker to breathe and is helpful in all hazardous atmospheres. In recent years experience has shown that this second type of self rescuer is more effective.

Subsection 692(b)

An employer must ensure that every person who enters an underground coal mine must be in possession at all times of an oxygen generating self rescuer. This requirement does not necessarily imply that the unit must be worn on a belt. It does require that the unit be readily available at all times.

Subsection 692(c)(d)(e)

Every person who enters an underground mine must be trained to use an oxygen generating self rescuer properly. Typically this involves an explanation and demonstration of the self rescuer often followed by a hands-on exercise of actually putting on a training unit. The context of typical emergencies and escape routes should be explained. In mines in which the walking time from the furthest working section to fresh air is greater that the life of a single unit, additional units must be provided so that an exhausted unit may be replaced with a fresh one. In such mines, it is important that training include the procedure required to exchange a used unit for a fresh one without inhaling contaminated air.

Such training ensures that there is no uncertainty or hesitation in worker response when putting on or exchanging oxygen-generating self rescuer units. Experience in incidents around the world has shown that workers have perished while trying to put on their self rescuer unit, possibly due to inadequate or out-dated training. Thus this section requires refresher training every three months.

Records of worker training in the use of self rescuer devices must be maintained and kept at the mine. This confirms that training has taken place and helps with the scheduling of refresher training.

Subsection 692(f)

The employer is responsible for providing a sufficient number of self rescuers to supply one unit to every person underground. This includes personnel not rostered to work every shift but who are required for other reasons e.g. to make inspections or visitors.

The employer must also ensure that additional self rescuers are stored and strategically located in caches along the emergency escape route(s). This allows any person to put on a fresh unit to ensure that they do not run out of oxygen when walking from the most distant working section to the defined emergency exit during a mine emergency.