Health and Safety Management – A Permit to Work is a procedure, a written permit form, which is used to authorize and control high risk work activities. This permit, when effectively developed and implemented, serves as a checklist to ensure that all hazards, control measures, procedures and general safe work requirements are identified, documented, reviewed and understood by the personnel who will be involved with the activities. It provides a record of the authorization and completion of the hazardous activities, the controls and the authorization for the task.
Specifically, the permit identifies and clearly describes the task that is to be completed and ensures that all potentially hazardous jobs are controlled and properly authorized and responsibilities for proceeding with the assignment within a specified time and within specified limitations are stated. It also ensures that all hazards associated with the job have been identified. All necessary safety procedures for controlling the risks are properly implemented while the job is being completed and that the site is left in a safe condition when the assignment is completed or suspended. Through the permit, all affected personnel will be informed that the activity is being done and the plant and equipment will be returned to a safe condition when the job has been completed or suspended.
A Permit should be used for all high risk activities where existing controls have not reduced the risks to acceptable levels. Additional risk controls will be developed and implemented through the Permit process (procedure) to ensure that the risks are reduced to acceptable levels. Often, it is used for non-routine tasks. A “non-routine” task is any task that is not described in established procedures and which involves hazardous activities that must be controlled to reduce the risks to acceptable levels.
The main types of Permits to Work commonly used are described below.
Hot Work Permit
By definition, hot work is any work that could create a source of ignition that could result in a fire/explosion. Examples of hot work include, but are not restricted to, welding and torch cutting. Spark producing tools such as grinders, power tools such as drills, use of explosives among many others. A Hot Work Permit is necessary for any of these activities.
Cold Work Permit
Cold work includes other high risks activities such as any work carried out in equipment or plant components. That are under pressure or are energized in some form e.g. mechanical energy, work on any equipment or plant components that are at extreme temperatures (cold or hot), general construction, work on pressure vessels or tanks, work performed in the immediate vicinity of overhead power lines, work on equipment or plant components that contain hazardous materials, among many others. These activities will require a Cold Work Permit. Some jobs such as non-routine maintenance work or work on de-energized electrical circuits or energized circuits of under 120 volts may require Cold Work Permits.
Confined Space Entry Work Permit
A confined or partially confined space is any space having restricted access or egress. And/or which is or may become hazardous to personnel. Because of space design, construction and/or location, atmospheric content such as gas composition, or due to the materials in the confined space.
Examples of confined spaces include open or closed tanks, vessels, towers, furnaces, sewers, dry wells, ventilation. And exhaust ducts, pipes, boreholes, grain silos among many others. Such spaces are hazardous or may become hazardous because of their nature. Any work carried out in these areas will require a Permit to Work.
Electrical Work Permit
Electrical work is any work where the worker or the worker’s tools will intentionally be in contact with electrically energized circuits greater than 120 volts. Testing and/or the use of testing equipment is not considered electrical work, unless the testing requires. That the worker and/or the worker’s tools will intentionally be in contact with the electrically energized circuits. Electricity is dangerous and electrical work can be very dangerous when proper safe work procedures are not followed. All electrical work on electrically energized circuits above 120 volts require a work permit.
Excavation, Trenching and Ground Disturbance Work Permit
Trenching, excavating or ground disturbance is any work where excavation,trenching, tunnels, drilling, pile driving and scraping (earth removal) are done. In such work, there is a possibility of damaging buried pipes, electrical cables or other sub-surface equipment or structures. These activities require a work permit to ensure that all precautions are taken before the work commences.
Vehicle Entry Work Permit
Vehicle Entry permits are used whenever heavy-duty equipment such as cranes. Loaders or back-hoes will be entering areas. Where there is a possibility of volatile gas releases or the potential for serious, major or critical accidents occurring. Because of the vehicle entry into the area (e.g. potential for the vehicle striking and damaging equipment). In such instances, a work permit is used to ensure that all precautions have been taken.
The above types of work permits are used to ensure. That any high risk activity to be carried out is properly planned for. Authorized and precautions taken to mitigate any identified risks. That may potentially harm those performing the work or others who may be around the work site.