Mining by its very nature is hazardous. Demanding mining processes pose significant, daily risks to employees, contractors and visitors. Stakeholders require that accountability for safety on a mine is assigned to management in line with good governance and legislation, and demand that safety processes and records are opened to scrutiny.
Apart from the regrettable injuries and fatalities, safety-related stoppages in mining companies also result in lost production, lost profits, significant remedial costs and loss of reputation. It is therefore not surprising that efforts are being made by mining companies to improve their safe work procedures and reduce risk of an accident.
Accidents occur when a person is exposed to a source of uncontained energy. During plant work there are many sources that could cause harm, such as pressure, heights, mechanical and electrical. Properly designed plant and equipment have inherent safeguards such as physical guards, heat insulation, safety interlocks and pressure release valves. Under normal operation the plant functions safely by virtue of the inherent equipment and process design. However, there are many situations when non-routine work such as maintenance requires that these normal safeguards are removed or altered in such a way that a person could be exposed to a hazardous source of energy.
In order to determine the nature of the hazards and the risks involved with non-routine work, a job risk assessment is performed during the planning of the work. The purpose of this risk assessment is to identify the hazards associated with a task or activity, assess the probability and the consequences of something going wrong.
The risk assessment should also consider the controls in place (for example, personal protective equipment or isolations) and determine the residual risk and alert the people involved. Once the risks are understood and have been mitigated, and the residual risk understood, the work can take place in a safe manner.
An important objective of the risk assessment process is to identify low-risk or routine activities as distinct from high-risk or non-routine activities. In the case of routine activities, people are usually trained and while the activity might be inherently hazardous, the processes are governed by standard procedures and check lists. High-risk activities, on the other hand, rely on competent people doing the work, as well as a set of temporary controls such as isolations, personnel protective equipment, and standby personnel.
There are several systems that companies use to manage work in hazardous areas. These normally include a risk assessment system, a permit to work system, and an isolation management system. Sometimes these systems are a well designed integrated process, but in some companies the individual elements are often not understood and too much onus is placed on experience and human judgement.
Isolations are critical when people perform non-routine work in hazardous environments. Isolations are typically physical barriers put in place to prevent exposure to sources of harmful energy. Examples would include a slip plate between two flanges, a valve locked open or closed, and an electrical circuit isolated by racking out the switchgear. Isolations are temporary in nature as they relate to non-routine work. Isolation management can be a complex process and there are many best practices you can adopt in mining situations. For example, isolations can be managed with a simple tagging system whereby "do not operate" tags are printed and used on isolation points.
An even more reliable system is to use a combination of personal locks and supervisor locks. Higher levels of integrity can be achieved whereby isolations in the field are verified by using mobile devices which scan barcoded tags and validate the corresponding isolation point by reading RFID tags. Lock boxes or key safes can also be used to provide additional management and prevent locks from being accidentally removed before work is complete.
Management of isolations can become quite complex, particularly when multiple isolations are required for a job, and multiple overlapping jobs are taking place simultaneously in the same area. The system of managing isolations needs to be both simple and robust. Computer-based systems can play an important role in managing the complexity and improving the integrity of the process. Integrated computer systems that cater for risk assessments, permits to work and isolation management in a common safety system can dramatically reduce the inherent risk in hazardous situations. Mining companies around the world are increasingly implementing these systems and reaching levels of safety integrity on par with or better than any other industry.