| In order to evaluate the various potential controls | | | | - There may be a tendency to rely too much on |
| mechanism types the advantages and | | | | an automatic safety barrier and not recognize the |
| disadvantages of the different control | | | | need for a second effective barrier for the risk. |
| mechanisms should be taken into account in the | | | | Installation of Warning Devices |
| process of deciding on the appropriate | | | | The installation of warning devices that alert |
| mechanism. The following is a summary of the | | | | personnel, and others, of a potential or existing |
| advantages and disadvantages of some of the | | | | unwanted energy release in time to allow people |
| most popular control mechanisms used by | | | | to take remedial action or escape is another |
| companies. | | | | method of instituting controls. Such controls have |
| Design to Eliminate the Energy Source | | | | two components, the warning and the procedure |
| This implies that a design or action is introduced to | | | | to be followed should the warning be given. |
| virtually eliminate the risk by removing all the | | | | Examples are the beeper on a large reversing |
| energy. Examples are the replacement of a | | | | vehicle that alerts people to stay out of the area, |
| potentially carcinogenic chemical with a | | | | and a fire alarm and an evacuation procedure.o |
| non-carcinogenic one, and the use of incombustible | | | | Advantages: |
| materials in a fire risk area.o Advantages: | | | | - The risk is somewhat reduced. |
| - The risk is reduced to virtually zero. | | | | - It can be a low-cost method of reducing risk at |
| - A risk reduction measures taken at design stage | | | | any stage in the life of the system.o |
| can be a low-cost method.o Disadvantages: | | | | Disadvantages: |
| - The change may introduce other risks that | | | | - The residual or remaining risk will still require |
| must be identified, assessed and controlled. This | | | | further control. |
| can be costly if the system is beyond the design | | | | - The likelihood that personnel will respond to the |
| stage. | | | | alarm depends on factors such as the complexity |
| - It is not possible in many situations to utilize this | | | | of required response, stress and employee |
| methodology. | | | | perceptions( i.e. if the alarm is often heard it may |
| Design to Reduce the Energy Source | | | | be consciously or unconsciously ignored). |
| This approach requires that a design or action to | | | | Use of Personal Protective Equipment, Procedures |
| greatly reduce the risk by reducing or controlling | | | | and Training |
| the energy be implemented. Examples are the | | | | Procedures and training intended to reduce |
| reduction of on site chemical stocks, issuing | | | | personnel risks, including actions and equipment |
| smaller quantities from stores, and the application | | | | intended to protect the person from exposure to |
| of fire retardant coating to materials where fire is | | | | an unwanted energy release is normally |
| a hazard.o Advantages: | | | | introduced as the last resort to controlling risk. |
| - The risk, i.e. likelihood of the event or its | | | | Examples are respiratory protection equipment |
| consequences, is greatly reduced. | | | | such as portable breathing apparatus, and work |
| - Risk reduction measures taken at the design | | | | permit systems.o Advantages: |
| stage can be low cost.o Disadvantages: | | | | - All employees must be trained in the tasks they |
| - The residual or remaining risk may still be | | | | are perform and in dealing with the risks related |
| unacceptable. | | | | to the task. |
| - The change may introduce other risks that | | | | - It is usually easy to implement and has low |
| must be identified, assessed and controlled and | | | | costs.o Disadvantages: |
| this can be costly if the system is beyond the | | | | - This is the least effective means of control |
| design stage. | | | | because of its reliance on human behavior and |
| Installation of a Safety Device | | | | work site culture for success. |
| A design or modification involving a physical barrier | | | | - The likelihood of effectiveness greatly depends |
| or device that does not rely on human action and | | | | on the quality of the equipment, whether it is |
| is intended to protect targets from unwanted | | | | used properly and whether the standard work |
| energy flows is installed to arrest the energy | | | | practices are monitored. |
| source when it goes out of control. Examples are | | | | - Personal protective equipment imposes |
| the installation of earth leakage devices on | | | | restrictions on wearers, e.g. it may also reduce |
| electrical equipment, and an automatic fire | | | | hearing, mobility, peripheral vision, etc. |
| suppression system.o Advantages: | | | | Conclusion |
| - The risk can be significantly reduced if the | | | | The extent of the intervention to introduce |
| device is reliable. | | | | additional controls will be determined by the gap |
| - It can be a cost effective method of reducing | | | | existing between the current level of risk and the |
| risk at any stage in the life of the system.o | | | | tolerable level for that risk. The final decision to |
| Disadvantages: | | | | implement a specified control rests with senior |
| - The residual or remaining risk may still be | | | | management after quantifying the risk and having |
| intolerable. | | | | conducted a cost benefit analysis. |