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Hazards can be controlled using many different and often combined methods. The chosen control or often the easiest control is not necessarily the most effective method of control. Power Tech Industries Ltd. is obliged to control hazards from the highest risk hazard to the lowest risk hazard, and in doing so, consider the following hierarchy of controls for each hazard, in the identified order engineering, administrative, and ppe.
Engineering Controls
Engineering controls provide the highest degree of control because they eliminate or control the hazard at its source as close to where the problem is created as possible. Engineering controls are the preferred method of eliminating or controlling hazards. Engineering controls include the following:
Elimination – getting rid of a hazardous job, tool, process, machine or substance may be the best way of protecting workers. Examples include:
•Providing hoisting or materials handling equipment rather than have workers lift, lower, carry, etc. materials manually
•Eliminating the need for workers to work above grade, by lowering equipment that has to be accessed, such as valve controllers, gauges, sample points, etc.
•Providing proper working platforms instead of relying on personnel to access equipment or areas with ladders.
•Providing a chemical injection system that eliminates the need for workers to handle a hazardous chemical.
Substitution – if elimination is not practical, try substituting or replacing one substance or process with another. Examples include:
•Substituting a safer substance for a more hazardous one
•Replacing hazardous operations with less hazardous operations
•Selecting tools, equipment, and machinery that require less maintenance
•Replacing heavy, awkwardly shaped loads with lighter loads having handles and/or good gripping surfaces
•Storing hazardous materials in smaller quantities and containers
Redesign – hazards can sometimes be “engineered out” through redesign of the work site, workstations, work processes and jobs. Examples include:
•Providing fail-safe interlocks on equipment, doors, valves, etc.
•Installing guardrails on elevations
•Providing non-slip working surfaces
•Controlling traffic to avoid collisions
•Providing fixed detection systems and ESD systems
•Reducing the road grade
•Improving workplace lighting, ventilation, temperature control
•Using regulators, governors, and limit controls
Isolation – hazards can sometimes be isolated through containment or enclosure. Examples include:
•Negative-pressure fume hoods in laboratory settings
•Sound reducing enclosures for noisy equipment
Automation – some processes can be automated or mechanized. Examples include:
•Spot welding by industrial robots
•Assembly line operations that require repetitive manual handling by workers
Barriers – some hazards can be blocked. The further a barrier keeps a hazard away from workers, the more effective the barrier. Examples include:
•Guards on machines
•Enclosures and covers
•Welding screens to prevent welding flash from reaching workers
•Debris and personnel safety nets
•Machinery lockout systems that protect maintenance workers from exposure to electricity, heat, pressure, radiation, etc.
•Separating vehicle and pedestrian traffic
Absorption – examples include:
•Baffles that block or absorb noise
•Local exhaust ventilation that removes toxic gases, dusts, or fumes where they are produced
Dilution – some hazards can be diluted or dissipated. Examples include:
•General ventilation that dilutes the concentration of a hazardous gas with clean air from the outside. While suitable for less toxic substances, it is not effective for substances that are harmful at low concentrations.
Administrative Controls
When engineering controls are not possible or practical, administrative controls are the next approach to controlling hazards. Administrative controls are less effective than engineering controls since they do not eliminate the hazard. Examples include:
•Safe work procedures
•Hazard assessment / work permit
•Scheduling to reduce exposure to a hazard
•Transferring an operation to a contract service that has extensive experience in dealing with the hazard
•Training on the effects and controls of the hazard
Personal protective equipment (PPE)
Personal protective equipment (PPE) should only be used as a last line of defense to reduce the potentially harmful effects of exposure to a hazard. PPE is much less effective than engineering controls since it does not eliminate the hazard. The equipment must be used properly and consistently to be effective. Awkward or bulky PPE may prevent a worker from working safely. In some cases, PPE can increase the likelihood of hazards such as heat stress and tripping and falling.
Often, effective control of hazards requires a combination of different types of the above controls. All control measures must meet legislation and be developed by following the above hierarchy of control methods. Supervisors and workers that may be affected by the hazard and control measures will be involved in developing the controls to mitigate the hazard.
All hazards shall be recorded, appropriate controls shall be identified and assigned for corrective action to a specified person and date. The hazard and control methods will be monitored by the immediate Supervisor to ensure they are effective. Final completion of these corrective actions shall be the responsibility of management. Each corrective action shall be signed off as they are completed.